The synergistic stimulating effect of combined intake of carbohydrate and protein on plasma insulin concentration has been reported previously. However, it remains unclear whether the amount of protein ingested after exercise affects the concentrations of plasma insulin and amino acids. This study of trained men compared the effects of post-exercise co-ingestion of carbohydrate plus different amounts of whey protein hydrolysates (WPHs) with carbohydrate alone on (1) blood biochemical parameters of carbohydrate metabolism during the post-exercise phase, and (2) endurance performance. Eight trained men exercised continuously for 70 min. Immediately after exercise and 30, 60, 90, and 120 min later, the participants received supplements containing: (1) 17.5 g carbohydrate, (2) 3.0 g WPHs and 17.5 g carbohydrate (L-WPH), or (3) 8.0 g WPHs and 17.5 g carbohydrate (H-WPH). After a 2-h recovery period, the participants performed an endurance performance test. The concentrations of blood glucose were lower and plasma insulin significantly higher in the H-WPH trial compared with the carbohydrate trial. The concentrations of plasma amino acids were increased in a dose-dependent manner following ingestion of different amounts of WPHs with carbohydrate. Endurance performance was not significantly different between the three trials. Co-ingestion of carbohydrate and H-WPH was more effective than ingestion of carbohydrate alone for stimulating insulin secretion and increasing the availability of plasma amino acids. These results suggest that plasma concentrations of amino acids during the recovery period are determined by the amount of dietary protein ingested, and that it is necessary to increase the concentration of plasma amino acids above a certain level to stimulate insulin secretion.

The present study elucidated the effects of habitual rowing exercise on arterial stiffness and plasma levels of the vasoconstrictor endothelin-1 and the vasodilator nitric oxide (NO) in older men. Eleven rowers (68.0 +/- 1.6 years) and 11 sedentary control older men (64.9 +/- 1.1 years) were studied. Peak oxygen uptake (36.0 +/- 1.7 vs. 27.7 +/- 1.9 ml . kg(-1) . min(-1)), leg press power (1346 +/- 99 vs. 1077 +/- 68 W), and HDL-cholesterol (75 +/- 5 vs. 58 +/- 3 mg . ml(-1)) were higher and triglyceride (78 +/- 9 vs. 120 +/- 14 mg . ml(-1)) was lower in rowers than in control participants (all P < 0.05). Arterial stiffness indices (carotid beta-stiffness and cardio-ankle vascular index) and plasma endothelin-1 and NOx (nitrite+nitrate) levels did not differ between the two groups. These results suggest that habitual rowing exercise in older men is associated with high muscle power and aerobic capacity, and favourable blood lipid profile without affecting arterial stiffness or plasma levels of endotheline-1 and NO.

The synergistic stimulating effect of combined intake of carbohydrate and protein on plasma insulin concentration has been reported previously. However, it remains unclear whether the amount of protein ingested after exercise affects the concentrations of plasma insulin and amino acids. This study of trained men compared the effects of post-exercise co-ingestion of carbohydrate plus different amounts of whey protein hydrolysates (WPHs) with carbohydrate alone on (1) blood biochemical parameters of carbohydrate metabolism during the post-exercise phase, and (2) endurance performance. Eight trained men exercised continuously for 70 min. Immediately after exercise and 30, 60, 90, and 120 min later, the participants received supplements containing: (1) 17.5 g carbohydrate, (2) 3.0 g WPHs and 17.5 g carbohydrate (L-WPH), or (3) 8.0 g WPHs and 17.5 g carbohydrate (H-WPH). After a 2-h recovery period, the participants performed an endurance performance test. The concentrations of blood glucose were lower and plasma insulin significantly higher in the H-WPH trial compared with the carbohydrate trial. The concentrations of plasma amino acids were increased in a dose-dependent manner following ingestion of different amounts of WPHs with carbohydrate. Endurance performance was not significantly different between the three trials. Co-ingestion of carbohydrate and H-WPH was more effective than ingestion of carbohydrate alone for stimulating insulin secretion and increasing the availability of plasma amino acids. These results suggest that plasma concentrations of amino acids during the recovery period are determined by the amount of dietary protein ingested, and that it is necessary to increase the concentration of plasma amino acids above a certain level to stimulate insulin secretion.

Objective: Depletion of glycogen stores is associated with fatigue during both sprint and endurance exercises and therefore it is considered important to maintain adequate tissue stores of glycogen during exercise. The aims of the present study in rats were therefore to investigate the effects of preexercise supplementation with carbohydrate and whey protein hydrolysates (WPH) on glycogen content, and phosphorylated signaling molecules of key enzymes that regulate glucose uptake and glycogen synthesis during exercise.
Methods: Male SD rats were used in the study (n = 7/group). Prior to exercise, one group of rats was sacrificed, whereas the other groups were given either water, glucose, or glucose plus WPH solutions. After ingestion of the test solutions, glycogen-depleting exercise was carried out for 60 min. The rats were then sacrificed and the triceps muscles excised quickly.
Results: Compared to water or glucose only, preexercise ingestion of glucose plus WPH caused a significant attenuation of muscle glycogen depletion during the postexercise period. Coingestion of glucose and WPH also significantly lowered phosphorylated glycogen synthase levels compared to ingestion of water only. In the glucose plus WPH group, the levels of phosphorylated Akt were increased significantly compared to the group ingesting water only, while the levels of phosphorylated PKC were significantly higher than in the groups ingesting only water or glucose.
Conclusion: Taken together, these results indicate that, compared to ingestion of glucose or water only, preexercise ingestion of carbohydrate plus WPH activates skeletal muscle proteins of key enzymes that regulate glucose uptake and glycogen synthesis during exercise, thereby attenuating exercise-induced glycogen depletion. (C) 2011 Elsevier Inc. All rights reserved.

Energy requirements can be estimated from resting energy expenditure (REE). However, little is known about factors influencing REE in Japanese female athletes. This study was performed to evaluate the relationship between REE and body composition in Japanese female athletes with a wide range of body sizes. Ninety-three athletes (age 20.3 +/- 1.2y, height 162.8 +/- 6.4 cm, body weight (BW) 57.0 +/- 9.2 kg, fat-free mass (FFM) 45.4 +/- 6.2 kg) were classified into three groups according to BW: small-size (S) (n=34), medium-size (M) (n=34), and large-size (L) (n=25). Systemic and regional body compositions (skeletal muscle (SM), fat mass (FM), bone mass (BM), and residual mass (RM)) were estimated by dual energy X-ray absorptiometry (DXA). Measured resting energy expenditure (REEm) was evaluated by indirect calorimetry. Marked differences were found in REEm (S: 1,111 +/- 150, M: 1,242 +/- 133, L: 1,478 +/- 138 kcal/d), and systemic and regional body compositions among the three groups. REEm was strongly correlated with PPM, and absolute values of RM and SM increased significantly according to body size. There was good agreement between REEm and estimated REE (REEe) from the specific metabolic rates of four major organ tissue level compartments. These data indicate that REE for female athletes can be attributed to changes in organ tissue mass, and not changes in organ tissue metabolic rate. That is, change in REE can be explained mainly by the change in PPM, and REE can be assessed by PPM in female athletes regardless of body size.

The number of lean young women has been increasing. Fear of being fat may induce unnecessary attempts to reduce body weight, which can cause several types of illness. Many investigations have demonstrated dysfunction of the hypothalamus and metabolic differences in patients with anorexia nervosa. However, it is unclear whether there are any differences in physical characteristics between women with lower body weight and no illness compared to those of normal body weight. In this study, we investigated the differences in body composition, biochemical parameters, and resting energy expenditure (REE) between young women with low and normal body mass index (BMI). Twenty lean women (BMI < 18.5 kg/m(2)) and 20 normal women (18.5 <= BMI < 25 kg/m(2)) were recruited for this study. Body composition, biochemical parameters, and REE (REEm: measurement of REE) were measured, and the REE (REEe: estimation of REE) was estimated by using a prediction model. Marked differences were found in body composition. All of the values of blood analysis were in the normal ranges in both groups REEm (kcal/d and kcal/kg BW/d) was significantly lower in lean than in normal women, but there were no significant differences in the REEm to fat free mass (PPM) ratio between the two groups. In addition, there was good agreement between REEm and REEe obtained from the specific metabolic rates of four tissue organs. These data indicate that the lean women without any illness have normal values of biochemical parameters and energy metabolism compared to women with normal BMI.

Habitual moderate-to-vigorous-intensity physical activity attenuates arterial stiffening. However, it is unclear whether light physical activity also attenuates arterial stiffening. It is also unclear whether light physical activity has the same effects in fit and unfit individuals. This cross-sectional study was performed to determine the relationships between amount of light physical activity determined with a triaxial accelerometer and arterial stiffness. A total of 538 healthy men and women participated in this study. Subjects in each age category were divided into either high-light or low-light physical activity groups based on daily time spent in light physical activity. Arterial stiffness was measured by carotid-femoral pulse wave velocity. Two-way ANOVA indicated a significant interaction between age and time spent in light physical activity in determining carotid-femoral pulse wave velocity (P<0.05). In the older group, carotid femoral pulse wave velocity was higher in the low-light physical activity level group than in the high-light physical activity level group (945 +/- 19 versus 882 +/- 16 cm/s; P<0.01). The difference remained significant after normalizing carotid-femoral pulse wave velocity for amounts of moderate and vigorous physical activity. The carotid-femoral pulse wave velocity (r=-0.47; P<0.01) was correlated with daily time spent in light physical activity in older unfit subjects. No relationship was observed in older fit subjects. These results suggested that longer time spent in light physical activity is associated with attenuation of arterial stiffening, especially in unfit older people. (Hypertension. 2010;56:540-546.)

Exercise training induces various adaptations in skeletal muscles. However, the mechanisms remain unclear. In this study, we conducted 2D-DIGE proteomic analysis, which has not yet been used for elucidating adaptations of skeletal muscle after high-intensity exercise training (HIT). For 5 days, rats performed HIT, which consisted of 14 20-s swimming exercise bouts carrying a weight (14% of the body weight), and 10-s pause between bouts. The 2D-DIGE analysis was conducted on epitrochlearis muscles excised 18 h after the final training exercise. Proteomic profiling revealed that out of 800 detected and matched spots, 13 proteins exhibited changed expression by HIT compared with sedentary rats. All proteins were identified by MALDI-TOF/MS. Furthermore, using western immunoblot analyses, significantly changed expressions of NDUFS1 and parvalbumin (PV) were validated in relation to HIT. In conclusion, the proteomic 2D-DIGE analysis following HIT-identified expressions of NDUFS1 and PV, previously unknown to have functions related to exercise-training adaptations.

The effect of protein fractionation on the bioavailability of amino acids and peptides and insulin response and whether the protein source influences these effects in humans are poorly understood. This study compared the effects of different sources and degrees of hydrolysis of dietary protein, independent of carbohydrate, on plasma amino acid and dipeptide levels and insulin responses in humans. Ten subjects were enrolled in the study, with five subjects participating in trials on either soy or whey protein and their hydrolysates. Protein hydrolysates were absorbed more rapidly as plasma amino acids compared to nonhydrolyzed protein. Whey protein also caused more rapid increases in indispensable amino acid and branched-chain amino acid concentrations than soy protein. In addition, protein hydrolysates caused significant increases in Val-Leu and lle-Leu concentrations compared to nonhydrolyzed protein. Whey protein hydrolysates also induced significantly greater stimulation of insulin release than the other proteins. Taken together, these results demonstrate whey protein hydrolysates cause significantly greater increases in the plasma concentrations of amino acids, dipeptides, and insulin.

Recent studies showed that a combination of carbohydrate and protein was more effective than carbohydrate alone for replenishing muscle glycogen after exercise. However, it remains to be unclear whether the source or degree of hydrolysis of dietary protein influences post-exercise glycogen accumulation. The aim of this study was to compare the effect of dietary protein type on glycogen levels in the post-exercise phase, and to investigate the effects of post-exercise carbohydrate and protein supplementation on phosphorylated enzymes of Akt/PKB and atypical PKCs. Male Sprague-Dawley rats, trained for 3 days, swam with a 2% load of body weight for 4 h to deplete skeletal muscle glycogen. Immediately after the glycogen-depleting exercise, one group was killed, whereas the other groups were given either glucose or glucose plus protein (whey protein, whey protein hydrolysates (WPH), casein hydrolysates or branched-chain amino acid (BCAA) solutions. After 2 h, the rats were killed, and the triceps muscles quickly excised. WPH caused significant increases in skeletal muscle glycogen level (5.01 +/- A 0.24 mg/g), compared with whey protein (4.23 +/- A 0.24 mg/g), BCAA (3.92 +/- A 0.18 mg/g) or casein hydrolysates (2.73 +/- A 0.22 mg/g). Post-exercise ingestion of glucose plus WPH significantly increased both phosphorylated Akt/PKB (131%) and phosphorylated PKC zeta (154%) levels compared with glucose only. There was a significant positive correlation between skeletal muscle glycogen content and phosphorylated Akt/PKB (r = 0.674, P < 0.001) and PKC zeta (r = 0.481, P = 0.017). Post-exercise supplementation with carbohydrate and WPH increases skeletal muscle glycogen recovery by activating key enzymes such as Akt/PKB and atypical PKCs.

This study investigated regulation of autophagy in slow-twitch soleus and fast-twitch plantaris muscles in fasting-related atrophy. Male Fischer-344 rats were subjected to fasting for 1, 2, or 3 days. Greater weight loss was observed in plantaris muscle than in soleus muscle in response to fasting. Western blot analysis demonstrated that LC3-II, a marker protein for macroautophagy, was expressed at a notably higher level in plantaris than in soleus muscle, and that the expression level was fasting duration-dependent. To identify factors related to LC3-II enhancement, autophagy-related signals were examined in both types of muscle. Phosphorylated mTOR was reduced in plantaris but not in soleus muscle. FOXO3a and ER stress signals were unchanged in both muscle types during fasting. These findings suggest that preferential atrophy of fast-twitch muscle is associated with induction of autophagy during fasting and that differences in autophagy regulation are attributable to differential signal regulation in soleus and plantaris muscle. (C) 2010 Elsevier Inc. All rights reserved.

We previously reported that 14 bouts of exhaustive high-intensity intermittent training [20 s periods of swimming while carrying a weight (14% of body weight), separated by pauses of 10 s] is the highest stimuli in terms of exercise training-induced glucose transporter 4 (GLUT-4) expression in rat epitrochlearis (EPI) muscles. In the present study, we found that the GLUT-4 protein content in the skeletal muscle of male Sprague-Dawley rats (age 5 weeks old; body weight 90-110 g) that underwent intermittent exercise training of 3 and 14 bouts of 20 s swimming for 5 days was increased over age-matched sedentary control rats by 75 and 71%, respectively, 18 h after the last bout of exercise. These results suggest that GLUT-4 content in rat EPI muscle increases dramatically after very short (60 s) and nonexhaustive high-intensity intermittent exercise training.

Arterial stiffening, hypertension and left ventricular (LV) remodelling are associated with increased risk of cardiovascular disease. Cardiorespiratory fitness is associated with cardiovascular function and reduced risk of cardiovascular disease. This cross-sectional study was carried out to determine the relationships between cardiorespiratory fitness, arterial stiffness, blood pressure (BP) and LV remodelling in women. On the basis of peak oxygen uptake, a total of 159 premenopausal (young) and postmenopausal (older) women were categorized into either low (unfit) or high (fit) cardiorespiratory fitness groups. The arterial stiffness and LV remodelling were measured by brachial-ankle pulse wave velocity (baPWV) and carotid augmentation index (AI) and LV relative wall thickness (RWT). Two-way analysis of variance indicated a significant interaction between age and cardiorespiratory fitness in baPWV, carotid AI, BP and RWT. In the older group, arterial stiffness (baPWV; 1401 +/- 231 vs 1250 +/- 125cms(-1), P<0.01, AI; 32.9 +/- 9.9 vs 24.8 +/- 10.1%, P<0.01), systolic blood pressure (SBP) (130 +/- 22 vs 117 +/- 15mmHg, P<0.01) and RWT (0.47 +/- 0.08 vs 0.42 +/- 0.04, P<0.05) in fit women were lower than in unfit women. In older women, RWT was significantly related to baPWV (r = 0.46, P<0.01), carotid AI (r = 0.29, P<0.05), SBP (r = 0.57, P<0.01). (V) over dot(2peak) (r = -0.32, P<0.05). In young women, they were not significant correlations, except for a weak correlation between RWT and SBP (r = 0.21, P<0.05). These results suggest that higher cardiorespiratory fitness is associated with lower arterial stiffness, BP and RWT in older women. Journal of Human Hypertension (2010) 24, 197-206; doi:10.1038/jhh.2009.57; published online 16 July 2009

CAO Z., N. MIYATAKE. M. HIGUCHI, M. MIYACHI, K. ISHIKAWA-TAKATA, and I. TABATA. Predicting (V)over dotO(2max) with an Objectively Measured Physical Activity in Japanese women. Med. Sci. Sports Exerc., Vol. 42. No. 1 pp. 179-186, 2010. Purpose: To investigate the use of the accelerometer-determined physical activity (PA) intensity variables as the objective PA variables for estimating (V)over dotO(2max) in Japanese adult women. Methods: The subjects Of this Study were 148 Japanese women aged 20 to 69 yr. Maximal oxygen Uptake was measured with a maximal incremental test oil a bicycle ergometer. Daily step Counts (SC) and file amount Spent ill moderate to vigorous PA (MVPA) and Vigorous PA (VPA) were measured using accelerometer-based activity monitors for 7 consecutive days. Using data of age. SC, MVPA, or VPA, and either body mass index (BMI) or waist circumference (WC), the nonexercise (V)over dotO(2max) prediction models Were derived as BMI model(MVPA), WC models(MVPA), BMI models(VPA), and WC models(VPA), and cross-validated by using two separate cross-validation procedures. Results: SC, MVPA, and VPA were significantly related to (V)over dotO(2max) (r = 0.43, r = 0.52, and r = 0.58, respectively), The Multiple correlation coefficients for the BMI and WC models(MVPA) were 0.83and 0.85, respectively and for the BMI and WC models(MVPA), they were 0.85 and 0.86. respectively. The SEE Was 3.3 and 3.1 mL.kg(-1).min(-1) for the BMI and WC models(MVPA), respectively, and it Was 3.1 and 3.0 mL.kg(-1).min(-1) for the BMI and WC models(VPA), respectively, All regression models demonstrated a high level of cross-validity Supported by the minor shrinkage of the coefficient of determination and the increment of SEE in file predicted residual sum of squares procedure, and by small constant errors for the Subgroups of age, SC, and (V)over dotO(2max) between 25 and 35 mL.kg(-1).min(-1). Conclusions: This study demonstrated that multiple regression models using data of MVPA or VPA were useful in predicting for Japanese adult women.

This study examined the effects of maintaining euhydration by ingesting fluids with or without carbohydrate on subjective responses of untrained men during prolonged exercise in a hot environment. Six healthy untrained subjects completed 90 min of cycling exercises at 55% maximal oxygen consumption (V(O2max)) in a hot environment (temperature: 28 degrees C. humidity: 50%) under three different experimental conditions. During the first trial. subjects did not ingest fluids during exercise (dehydration (DH) trial). In the second and third trials, subjects received mineral water (MW) and hypotonic fluid containing carbohydrate (HF), respectively, in amounts equaling their weight loss in the DH trial. At the end of exercise, the overall rating of perceived exertion (RPE-O) was lower in the MW and HF trials than in the DH trial (14.3+/-1.0 and 13.7+/-0.6 vs 17.7+/-1.0. p<0.05. respectively). RPE-cardiovascular and RPE-legs were lower at the end of exercise in the HF trial compared with the DH trial. V(O2), heart rate (HR), and rectal temperature increased during exercise in the three trials. At the end of exercise, the drift in V(O2) was lower in the MW and HF trials than in the DH trial (304+/-41 and 339+/-40 vs 458+/-33 mL, p<0.05. respectively). HR at the end of exercise in the HF trial was lower than in the DH. trial (158+/-5 vs 173+/-7 bpm. p<0.05). These results suggest that maintaining euhydration during prolonged exercise in untrained men could attenuate RPE-O and that hypotonic electrolyte-carbohydrate solution could attenuate RPE-legs during exercise.

It has recently been reported that a 4-wk high-fat diet gradually increases skeletal muscle peroxisome proliferator activated receptor (PPAR) gamma coactivator-1 alpha (PGC-1 alpha) protein content, which has been suggested to regulate GLUT-4 gene transcription. However, it has not been reported that a high-fat diet enhances GLUT-4 mRNA expression and protein content in skeletal muscle, suggesting that an increase in PGC-1 alpha protein content is not sufficient to induce muscle GLUT-4 biogenesis in a high-fat fed animal. Therefore, we first evaluated the relationship between PGC-1 alpha and GLUT-4 expression in skeletal muscle of rats fed a high-fat diet for 4 wk. The PGC-1 alpha protein content in rat epitrochlearis muscle significantly increased by twofold after the 4-wk high-fat diet feeding. However, the high-fat diet had no effect on GLUT-4 protein content and induced a 30% decrease in GLUT-4 mRNA expression in rat skeletal muscle (p<0.05). To clarify the mechanism by which a high-fat diet downregulates GLUT-4 rnRNA expression, we next examined the effect of PPAR delta activation. which is known to occur in response to a high-fat diet. on GLUT-4 rnRNA expression in L6 myotubes. Incubation with 500 nm GW501516 (PPAR delta activator) for 24 h significantly decreased GLUT-4 rnRNA in L6 myotubes. Taken together, these findings suggest that a high-fat diet downregulates GLUT-4 mRNA, possibly through the activation of PPAR delta, despite an increase in PGC-1 alpha protein content in rat skeletal muscle, and that a posttranscriptional regulatory mechanism maintains GLUT-4 protein content in skeletal muscle of rats fed a high-fat diet.

Reduced response to reactive hyperemia (RH) in the extremities reflects impaired endothelium-dependent vasodilation of the microvasculature. The aims of the present study were to determine whether resistance training and a combination of aerobic and resistance training increase the endothelial vasodilation of the forearm assessed by RH. A total of 39 young men were assigned to either high-intensity resistance training (HIR; six types of exercises, 80% 1RM x 10 repetitions x 3 sets, n = 14) or moderate-intensity resistance training (MIR; six types of exercises, 50% 1RM x 16 repetitions x 3 sets, n = 14) or a combination of high-intensity resistance training and moderate-intensity endurance training (COMBO; HIR and 60% maximal heart rate x 30 min, n = 11) groups. We measured forearm blood flow response to RH before and after 4 months of exercise intervention. All training groups increased maximal strength in all muscle groups tested (all P < 0.05). After 4 months of training, the forearm blood flow during RH increased significantly in the MIR and COMBO groups, from 57 +/- 4 to 66 +/- 7 ml/min per 100 ml tissue and from 59 +/- 6 to 74 +/- 8 ml/min per 100 ml tissue, respectively (both P < 0.05). There was no change in the response to RH in the HIR groups. In conclusion, the findings in this study demonstrate that combined resistance and aerobic training may affect the vasoreactivity response to RH in the forearm, but not resistance training alone.

Sarcopenia is characterized by increased regenerating myofibres and decreased myofibre size. Sarcopenia progression might be partially regulated by ageing-related signals associated with necrotic fibre disruption and nuclear apoptosis. This study sought to identify ageing-related signals in aged atrophying skeletal muscle by comparison with unloaded muscle atrophy in adults. Adult (6-month) and old (32-month) rats were used. Some adult rats were subjected to 2 weeks of hindlimb unloading (6-month-HU). Histological analysis found that regenerating fibres increased by about 30-fold only in 32-month aged soleus muscle compared with 6-month rats. The number of apoptotic DNA fragmented nuclei was increased by 3.9-fold in 6-month-HU and 2.8-fold in 32-month rats. Cleaved caspase-3 was observed at high levels on basal membranes and in nuclei in 32-month rats. By Western blot analysis additional ageing-related signals could be identified since (1) phosphorylated Bcl-2 content was increased in both cytosolic and mitochondrial fractions; (2) ER stress signal proteins caspase-12, CHOP/GADD153, and GRP78 were increased; and (3) stress-inducible chaperone HSP70 was decreased in soleus muscle from 32-month but not changed in 6-month-HU rats. We conclude that activation of ageing-related signals may mediate necrotic myofibre disruption and nuclear apoptosis induction that contribute to progression of sarcopenia. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

Objective: To evaluate the possibility that measurement of the magnitude and distribution of fundamental somatic heat-producing units using dual-energy X-ray absorptiometry (DXA) can be used to estimate resting energy expenditure (REE) in both young and elderly women with different aerobic fitness levels.
Subjects and methods: Peak oxygen uptake (VO(2) peak) and REE(m) were directly measured in 116 young (age: 22.3 +/- 2.1 years) and 72 elderly (63.3 +/- 6.4 years) women. The subjects were divided into four groups according to categories of age and VO(2) peak; young: high fitness (YH, n = 58); low fitness (YL, n = 58); elderly: high fitness (EH, n = 37) and low fitness (EL, n = 35). Using DXA, systemic and regional body compositions were measured, and REE(e) was estimated from the sum of tissue organ weights multiplied by corresponding metabolic rate.
Results: Although there were remarkable differences in systemic and regional body compositions, no significant differences were observed between REE(m) and REE(e) in the four groups. REE(e) significantly correlated with REE(m) in elderly as well as young women; the slopes and intercepts of the two regression lines were statistically not different between the elderly and young groups (elderly: y = 0.60x+472, r = 0.667; young: y = 0.78x+250, r = 0.798; P < 0.001, respectively). A Bland-Altman analysis did not indicate bias in calculation of REE for all the subjects.
Conclusion: These results suggest that REE can be estimated from tissue organ components in women regardless of age and aerobic fitness.

Objective: To investigate the relationships between regional skeletal muscle mass (SM mass) and bone mineral indices and to examine whether bone mineral content (BMC) normalized to SM mass shows a similar decrease with age in young through old age.
Subjects/Methods: One hundred and thirty-eight young and postmenopausal women aged 20-76 years participated in this study and were divided into three groups: 61 young women, 49 middle-aged postmenopausal women and 28 older postmenopausal women. Muscle thickness (MTH) was determined by ultrasound, and regional SM mass (arm, trunk and leg) was estimated based on nine sites of MTH. Whole-body and regional lean soft tissue mass (LSTM), bone mineral density (BMD) and BMC (whole body, arms, legs and lumbar spine) were measured using dual-energy X-ray absorptiometry.
Results: Ultrasound spectroscopy indicated that SM mass is significantly correlated with site-matched regional bone mineral indices and these relationships correspond to LSTM. The BMC and BMD in older women were significantly lower than those in middle-aged women. When BMC was normalized to site-matched regional SM mass, BMC normalized to SM mass in arm and trunk region were significantly different with age; however, whole-body and leg BMC normalized to SM mass showed no significant difference between middle-aged and older postmenopausal women.
Conclusions: The age-related differences in BMC were found to be independent of the ageing of SM mass in the arm and trunk region. However, differences in BMC measures of the leg and whole body were found to correspond to age-related decline of SM mass in postmenopausal women.

In earlier studies we showed that dietary whey protein increased skeletal muscle and liver glycogen content in exercise-trained rats. However, little is known about whether ingredients of whey protein stimulate skeletal muscle glycogen accumulation. The aim of this Study was to identify bioactive peptides in whey protein hydrolysates (WPH) which stimulated glucose uptake and glycogen synthesis rate in skeletal muscles. Branched-chain amino acid (BCAA)-containing dipeptides in WPH were identified using LC/MS/MS. L6 myotubes and isolated epitrochlearis muscles were used for the glucose uptake assays. The myotubes and muscles were incubated with or without 1 mM dipeptides, LY294002 a phosphoinositide 3-kinase (PI3-kinase) inhibitor. or GF102903X an atypical protein kinase C (aPKC) inhibitor, followed by measurement of 2-deoxyglucosc uptake. Isolated muscles were incubated for 3 h with or without 1 mM Ile-Leu to determine glycogen synthesis rate. The BCAA-containing dipeptides, Ile-Val, Leu-Val, Val-Leu, Ile-Ile, Leu-Ile, Ile-Leu, and Ile-Leu were detected in the WPH. by LC/MS/MS. These dipeptides caused significant stimulation in glucose uptake rate in the L6 myotubes. Ile-Leu. the main component in WPH, also stimulated glucose uptake in isolated skeletal muscles. Stimulation of glucose uptake by Ile-Leu was completely inhibited by treatment with either LY294002, or GF109203X in both L6 cells and isolated muscles. Ile-Leu increased glycogen contents in isolated muscles. These results suggest that BCAA-containing bioactive dipeptides in WPH stimulate glucose uptake in skeletal Muscles via the P13-kinase and aPKC pathways, resulting in increased skeletal muscle glycogen contents.

The purpose of the study was to develop a new non-exercise VO(2max) prediction model using a physical activity (PA) variable determined by pedometer-determined step counts (SC, steps day(-1)) in Japanese women aged 20-69 years old. Eighty-seven and 102 subjects were used to develop the prediction model, and to validate the new model, respectively. VO(2max) was measured using a maximal incremental test on a bicycle ergometer. SC was significantly related to VO(2max) (partial correlation coefficient r = 0.40, P < 0.001) after adjusting for BMI (kg m(-2)) and age (years). When the new prediction equation developed by multiple regression to estimate VO(2max) from age, BMI, and SC (R = 0.71, SEE = 5.3 ml kg(-1) min(-1), P < 0.001) was applied to the Validation group, predicted VO(2max) correlated well with measured VO(2max) (r = 0.81, P < 0.001), suggesting that SC is a useful PA variable for non-exercise prediction of VO(2max) in Japanese women.

The aim of this cross-sectional study was to compare body composition and risk factors of lifestyle-related diseases between young and older male rowers and sedentary controls. Healthy males aged 19-73 years participated in the study, and were divided into four groups: 26 young rowers, 24 senior rowers, 23 young sedentary controls, and 22 senior sedentary controls. Total and regional lean soft tissue, fat mass, and bone mineral density were measured using dual-energy X-ray absorptiometry. The HDL-cholesterol of senior rowers (67.4 +/- 13.4 mg . dl(-1)) was significantly (P < 0.05) higher than that of senior sedentary controls (59.2 +/- 11.9 mg . dl(-1)), while HDL-cholesterol was similar in senior rowers and young rowers (66.1 +/- 10.8 mg . dl(-1)). Arm, leg, and trunk lean soft tissue mass were significantly higher in senior rowers (5.6 +/- 0.6 kg, 18.2 +/- 1.8 kg, and 27.3 +/- 3.2 kg respectively) than in senior sedentary controls (5.1 +/- 0.4 kg, 16.3 +/- 1.4 kg, and 24.6 +/- 1.7 kg respectively; P < 0.05). Bone mineral density was also significantly higher in senior rowers than in senior sedentary controls (ribs, lumbar spine, and pelvic segments; P < 0.05). We conclude that age-related increases in the risk of lifestyle-related diseases, such as osteoporosis and sarcopenia, are attenuated in male rowers. These results suggest that regular rowing exercise may have a positive influence in the prevention of lifestyle-related diseases in older Japanese people.

CC-chemokine receptor 2 (CCR2) and its ligand, monocyte chemotactic protein-1 (MCP-1, also known as CCL2), are crucial for the recruitment of monocytes/macrophages to sites of inflammation. We conducted a series of experiments to investigate the relationship between stress, monocyte CCR2 expression and migration activity. First, we collected peripheral blood mononuclear cells (PBMC) from untrained subjects (n = 8) and measured CCR2 expression on CD14(+) monocytes cultured with cortisol, epinephrine and norepinephrine. Second, we collected PBMC from the subjects before and after they cycled for 60 min at 70% peak O-2 uptake (V-O2peak), and measured alterations in CCR2 expression on monocytes following exercise. Third, we cultured PBMC with serum obtained before and after exercise and the glucocorticoid antagonist RU-486 to determine the effect of cortisol on CCR2 expression in vitro. Last, we measured the ability of PBMC treated with serum or cortisol to migrate through membrane filters in response to CCL2. Cortisol (but not epinephrine or norepinephrine) increased CCR2 expression on monocytes in a dose- and time-dependent manner. Exercise did not influence CCR2 expression on PBMC, whereas incubation of PBMC with post-exercise serum significantly increased CCR2 expression. Both cortisol and post-exercise serum increased the migration of PBMC toward CCL2. The increase in CCR2 expression on PBMC following stimulation with cortisol and serum was blocked by the glucocorticoid receptor antagonist RU-486. In conclusion, cortisol released during exercise increased monocyte CCR2 expression and migration activity in vitro. These alterations may influence inflammation and regeneration of damaged tissue after acute stress. (C) 2008 Elsevier Inc. All rights reserved.

The present study was performed to test the hypothesis that the blood pressure (BP) response to resistance exercise in middle-aged men with stiffening arteries is greater than that in young men with compliant arteries. The BP responses to acute dynamic resistance exercise (leg press) at individual relative (low, moderate and high) and absolute intensities were investigated in both young and middle-aged men. A total of 21 sedentary healthy normotensive men, 21-25 years of age (young) and 41-59 years of age (middle-aged), were included in the study. At rest, the arterial compliance (simultaneous ultrasound and applanation tonometry) and muscle strength (leg press) were lower, and indices of arterial stiffness and BP were higher in the middle-aged men than in the young men (p < 0.05). There were no significant differences in height, body mass, or heart rate between the two groups. During exercise, the systolic BP of the middle-aged men at 80% one-repetition maximum (1RM) was significantly lower than that of the young men for the last half of the exercise period (p < 0.05). The amounts of change in systolic and diastolic BP from baseline to the end of resistance exercise were lower in the middle-aged men than in the young men at individual relative intensities (p < 0.05) and at individual absolute intensity. In contrast to our hypothesis, these findings indicated that the BP response during dynamic resistance exercise using large muscle groups may be attenuated in middle-aged men relative to young men.

Resistance training is a popular mode of exercise, but may result in stiffening of the central arteries. Changes in carotid artery diameter were determined using the cold pressor test (CPT), which results in production of nitric oxide via sympathetic activation and is one of the novel methods available for assessing endothelial function in the carotid artery. To investigate the effect of resistance training on endothelial function, we designed a cross-sectional study of carotid arterial vasoreactivity to CPT in men participating in regular resistance training with increased carotid arterial stiffness compared with age-matched control subjects. Twelve resistance-trained middle-aged men (age 38.7 +/- 1.7 years) and 17 age-matched control subjects (age 36.8 +/- 1.2 years) were studied. The direction and magnitude of changes in carotid artery diameter were measured by B-mode ultrasonography during sympathetic stress induced by submersion of the foot in ice slush for 90 s. Carotid arterial beta-stiffness index, and systolic and mean arterial blood pressure were higher (7.7 +/- 0.7 versus 6.0 +/- 0.4 arbitrary units, 116 +/- 2 versus 131 +/- 4 mmHg and 86 +/- 2 versus 95 +/- 2 mmHg, respectively, all P < 0.05) in the resistance training group compared with control subjects. There were, however, no significant differences in the amount or percentage change in carotid artery diameter in CPT between the two groups (resistance training group, 0.33 +/- 0.07 mm and 5.2 +/- 1.1%; control group, 0.37 +/- 0.06 mm and 5.8 +/- 0.9%, respectively). These findings suggest that while carotid arterial stiffening and higher blood pressure are observed in regular resistance-trained men, these are not associated with abnormalities in carotid arterial vasoreactivity to sympathetic stimulus, which implies intact endothelial function.

Endurance exercise induces mitochondrial biogenesis in skeletal muscle. It has been shown that lipin-1 acts as a transcriptional coactivator in liver, and stimulates gene expression of mitochondrial enzymes. We hypothesized that lipin-1 might be involved in exercise-induced mitochondrial biogenesis in skeletal muscle. The present investigation first demonstrated that lipin-1 mRNA in rat triceps muscle was increased by approximately 2-fold after an acute bout of endurance swimming exercise. Second, ectopic expression of lipin-1 in L6 myotube increased carnitine palmitoyltransferase-1 and delta-aminolevulinate synthase gene expression. Finally, lipin-1 mRNA expression in rat triceps muscle was significantly elevated at 6h after subcutaneous injections of 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) or clenbuterol, which are 5'-AMP-activated protein kinase (AMPK) and beta2-adrenergic receptor (beta2-AR) activators, respectively. These results may suggest that enhanced expression of lipin-1 is involved in exercise-induced mitochondrial enzyme adaptations, possibly through AMPK- and beta2-AR-related mechanisms.

It has been demonstrated in a previous study that resting energy expenditure (REE) is associated with adiponectin levels in the blood. However, body composition was not taken into consideration in that study. The purpose of the present study was to again investigate the relationship between blood adipocytokines and REE, adjusted by body composition, in both young and elderly women. REE and blood adipocytokines were measured in 115 young (age: 22.3 +/- 2.1 y, BMI: 21.3 +/- 1.9 kg/ml) and 71 elderly (63.4 +/- 6.5 y, 22.9 +/- 2.3 kg/m(2)) women. Dual energy X-ray absorptiometry was used to measure percent body fat. Fat mass and fat free mass (FFM) were calculated. REE (kcal/d and kcal/kg BW/d) was lower in elderly women than in young women, but no significant difference was observed in REE, expressed as kcal/kg FFM/d, between the two groups. Although elderly women had a higher percent body fat and higher serum leptin concentrations than young women, plasma adiponectin concentrations did not differ between young and elderly women. In elderly women, REE (kcal/d) was significantly and inversely correlated with plasma adiponectin concentration (r = -0.386, p<0.001), but REE expressed per kilogram of BW or FFM was not significantly correlated. Furthermore, no significant correlation was observed between REE (kcal/d) and concentrations of plasma adiponectin or serum leptin, after adjusting for potential confounders such as body composition and hormones, in either age group. These results suggest that adipocytokines do not influence REE in adult women.

Ventilatory threshold (VT) is an important predictor of cardiorespiratory fitness, such as peak oxygen uptake (<(V)over dot >(O2peak)) and is a valuable index of aerobic exercise intensity. However, little is known about the role of skeletal muscle ( SM) mass in the ageassociated decline of VT. Therefore, the present study was performed to investigate the effects of age on cardiopulmonary fitness normalised for regional SM mass in 1,463 Japanese men and women, and to determine the relevance of VT normalised to SM mass based on age and gender. Total, trunk and thigh SM mass were measured using an ultrasound method, while <(V)over dot >(O2pea)k and VT were determined during treadmill walking. <(V)over dot >(O2peak) was estimated using the predicted maximum heart rate ( HR) and the HR-<(V)over dot >(O2) relationship for sub- maximal treadmill walking. There were significant negative correlations between VT normalised for body mass and age in men and women ( P < 0.001). Age- associated declines were also observed in VT normalised for body mass in both men and women; however, VT normalised for SM mass was not significantly different with age. Significant correlations were also observed between thigh SM mass and VT in both men and women. These results suggest that thigh SM mass is closely associated with <(V)over dot >(O2peak) and/ or VT in both men and women, and the decrease in VT with age is predominantly due to an age- related decline of SM mass. Moreover, this study provides normative cardiorespiratory fitness data regarding VT normalised SM mass in healthy men and women aged 20 - 80 years.

Although it is clear that rowers have a large muscle mass, their distribution of muscle mass and which of the main motions in rowing mediates muscle hypertrophy in each body part are unclear. We examine the relationships between partial motion power in rowing and muscle cross-sectional area of the thigh, lower back, and upper arms. Sixty young rowers (39 males and 21 females) participated in the study. joint positions and forces were measured by video cameras and rowing ergometer software, respectively. One-dimensional motion analysis was performed to calculate the power of leg drive, trunk swing, and arm pull motions. Muscle cross-sectional areas were measured using magnetic resonance imaging. Multiple regression analyses were carried out to determine the association of different muscle cross-sectional areas with partial motion power. The anterior thigh best explained the power demonstrated by leg drive (r(2) = 0.508), the posterior thigh and lower back combined best explained the power demonstrated by the trunk swing(r(2) = 0.493), and the elbow extensors best explained the power demonstrated by the arm pull (r(2) = 0.195). Other correlations, such as arm muscles with leg drive power (r(2) = 0.424) and anterior thigh with trunk swing power (r(2) = 0.335), were also significant. All muscle cross-sectional areas were associated with rowing performance either through the production of power or by transmitting work. The results imply that rowing motion requires a well-balanced distribution of muscle mass throughout the body.

The combined intervention of isoflavone intake and walking exercise over 1 year in postmenopausal Japanese women exhibited a trend for a greater effect on prevention of bone loss at the total hip and Ward's triangle regions.
Introduction: The additive effects of isoflavones and exercise on bone and lipid metabolism have been shown in estrogen-deficient animals. In this study, we determined the effects of isoflavone intake, walking exercise, and their interaction on bone, fat mass, and lipid metabolism over I year in postmenopausal Japanese women.
Materials and Methods: A total of 136 postmenopausal women at < 5 years after the onset of menopause were randomly assigned to four groups: (1) placebo, (2) walking (45 minutes/day, 3 days/week) with placebo, (3) isoflavone intake (75 mg of isoflavone conjugates/day), and (4) combination of isoflavone plus walking. BMD, fat mass, serum lipid, and serum and urinary isoflavone concentrations were assessed.
Results: A significant main effect of isoflavone on the reduction in trunk fat mass was obtained at 12 months. Significant main effects of walking on the reduction in fat mass in the whole body and the trunk were observed at 3, 6, and 12 months and that in the legs and arms at 6 and 12 months. Serum high-density lipoprotein (HDL)-cholesterol concentration significantly increased by 12 months after the walking and the combined intervention. After 12 months, a significant main effect of isoflavone on BMD was observed only at Ward's triangle. Walking prevented bone loss at the total hip and the Ward's triangle to significant degrees. The effect of the combined intervention on BMD at total hip and Ward's triangle regions was greater than that of either alone. No significant interaction was observed between isoflavone and walking in any measurements recorded during the study.
Conclusions: Our study suggest that combined intervention of 75 mg/day of isoflavone intake and walking exercise 3 times/week for I year showed a trend for a greater effect on BMD at total hip and Ward's triangle regions than either alone. Intervention with isoflavone in postmenopausal Japanese women showed a modest effect on BMD compared with those in Westerners. Further studies over longer treatment duration that include assessment of BMD at various regions are necessary to ascertain the clinical significance of the combined intervention of isoflavone plus walking in postmenopausal women.

Cooperative effects of isoflavones and exercise on bone and lipid metabolism have been exhibited in estrogen-deficient animals; however, results from clinical trials have not been published. In this study, we determined the effects of isoflavone intake and walking and their interaction on bone and lipid metabolism in postmenopausal women over 24 weeks. The bioavailability and metabolism of isoflavones (daidzein in particular) were also examined to clarify the mechanism of their bone-protective effects in humans. One hundred twenty-eight Subjects were randomly assigned to 4 groups: placebo; placebo combined with walking (3 times per week); isoflavone intake (75 mg of isoflavones conjugates per day); and isoflavone combined with walking. The Subjects were classified by equol status (producers or nonproducers) as identified using production of equol from daidzein in fecal Culture. Bone mineral density (BMD), body composition, and serum concentrations of isoflavones were assessed. Scrum high-density lipoprotein cholesterol concentration significantly increased (6.1%, P = .03), and fat mass in the whole body significantly decreased (-4.3%, P = .0003) from the baseline in the combined intervention group. There were no significant differences in BMD between baseline and postintervention in any of the treatment groups. However, the percent changes in BMD in equol producers were -0.53% and +0.13% in the sub-whole body and total hip, respectively. This was significantly different compared with -1.35 and -1.77 for the sub-whole body and total hip, respectively, in nonproducers in the isoflavone group (P = .049 and .040, respectively). The mean scrum equol concentration was significantly higher in equol producers than in nonproducers in the isoflavone groups, but not in the placebo group. The combination of isoflavones and exercise exhibited favorable effects on serum lipid and body composition of postmenopausal women. The findings of this study suggest that the preventive effects of isoflavones on bone loss depend on the individual's intestinal flora for equol production. (c) 2006 Elsevier Inc. All rights reserved.

The basal metabolic rate (BMR) in 46 fit older people (age: 66&plusmn;3yrs., height: 163.3&plusmn;9.5cm, body weight (BW): 59.0&plusmn;10.4kg; mean&plusmn;SD) was evaluated in relation to the body composition (body fat mass (FM): 15.3&plusmn; 4.0kg, lean body mass (LBM): 43.7&plusmn;9.5kg). BMR for all the subjects was 1, 328&plusmn;218kcal/day, 22.6&plusmn;1.9kcal/kgBW/day, and 30.9&plusmn;3.6kcal/kgLBM/day. BMR (kcal/day) was significantly correlated with BW (r=0.87, p<0.001) and LBM (r=0.85, p<0.001). The height, BW, BMI and LBM were significantly higher in the males than in the females (p<0.01, respectively). No difference was apparent in FM between the two sexes. BMR (kcal/day) was higher in the males than in the females (p<0.01), but the males had lower BMR in terms of kcal/kgBW/day and kcal/kgLBM/day than the females (p<0.05 and p<0.01, respectively). No significant difference was apparent in the adjusted BMR (kcal/(kgLBM&plusmn;24.5)/day) between the males and females. A multiple-regression analysis showed the most powerful predictor to be LBM and the second most powerful to be FM of BMR in fit older people.

We tested the hypothesis that methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism, folic acid deficiency and riboflavin deficiency, independently or interactively, are important determinants of genomic stability, cell death, cell proliferation and homocysteine (Hcy) concentration in 9-d human lymphocyte cultures. Lymphocytes of seven wild-type (CC) and seven mutant (TT) homozygotes were cultured under the four possible combinations of deficiency and sufficiency of riboflavin (0 and 500 nmol/L) and folic acid (20 and 100 nmol/L) at a constant L-methionine concentration of 50 mumol/L. Viable cell growth was 25% greater in TT than in CC cells (P &lt; 0.05) and 32% greater at 100 nmol/L folic acid than at 20 nmol/L folic acid (P = 0.002). The comprehensive cytokinesis-block micronucleus assay was used to measure micronuclei (MNi; a marker for chromosome breakage and loss), nucleoplasmic bridges (NPB; a marker of chromosome rearrangement) and nuclear buds (NBUD, a marker of gene amplification). The MNi levels were 21% higher in TT cells than in CC cells (P &lt; 0.05) and 42% lower in the high folic acid medium than in the low folic acid medium (P &lt; 0.0001). The NBUD levels were 27% lower in TT cells than in CC cells (P &lt; 0.05) and 45% lower in the high folic acid medium than in the low folic acid medium (P &lt; 0.0001). High riboflavin concentration (500 nmol/L) increased NBUD levels by 25% (compared with 0 nmol/L riboflavin) in folate-deficient conditions (20 nmol/L folic acid medium; P &lt; 0.05), and there was an interaction between folic acid and riboflavin that affected NBUD levels (P = 0.042). This preliminary investigation suggests that MTHFR C677T polymorphism and riboflavin affect genome instability; however, the effect is relatively small compared with that of folic acid.

We tested the hypothesis that methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism, folic acid deficiency and riboflavin deficiency, independently or interactively, are important determinants of genomic stability, cell death, cell proliferation and homocysteine (Hcy) concentration in 9-d human lymphocyte cultures. Lymphocytes of seven wild-type (CC) and seven mutant (TT) homozygotes were cultured under the four possible combinations of deficiency and sufficiency of riboflavin (0 and 500 nmol/L) and folic acid (20 and 100 nmol/L) at a constant L-methionine concentration of 50 mumol/L. Viable cell growth was 25% greater in TT than in CC cells (P &lt; 0.05) and 32% greater at 100 nmol/L folic acid than at 20 nmol/L folic acid (P = 0.002). The comprehensive cytokinesis-block micronucleus assay was used to measure micronuclei (MNi; a marker for chromosome breakage and loss), nucleoplasmic bridges (NPB; a marker of chromosome rearrangement) and nuclear buds (NBUD, a marker of gene amplification). The MNi levels were 21% higher in TT cells than in CC cells (P &lt; 0.05) and 42% lower in the high folic acid medium than in the low folic acid medium (P &lt; 0.0001). The NBUD levels were 27% lower in TT cells than in CC cells (P &lt; 0.05) and 45% lower in the high folic acid medium than in the low folic acid medium (P &lt; 0.0001). High riboflavin concentration (500 nmol/L) increased NBUD levels by 25% (compared with 0 nmol/L riboflavin) in folate-deficient conditions (20 nmol/L folic acid medium; P &lt; 0.05), and there was an interaction between folic acid and riboflavin that affected NBUD levels (P = 0.042). This preliminary investigation suggests that MTHFR C677T polymorphism and riboflavin affect genome instability; however, the effect is relatively small compared with that of folic acid.

We evaluated the impact of bilateral leg extension power and fat-free mass on 2000 m rowing ergometer performance in 332 young oarsmen (age 21+/-2 years, height 1.76+/-0.05 m, body mass 62+/-6 kg; mean+/- s ). The 2000 m rowing performance time was correlated with height (1.62-1.93 m; R-2 = 0.23, P &lt;0.001), body mass (53-95 kg; R-2 = 0.53, P &lt;0.001), fat-free mass (47-82 kg; R-2 = 0.58, P &lt;0.001) and bilateral leg extension power (1202-3302 W; R-2 = 0.38, P &lt;0.001). Multiple regression analysis selected fat-free mass and bilateral leg extension power as regressor variables. Fat-free mass explained 58% of the variability in rowing performance and the inclusion of bilateral leg extension power improved the power of prediction by 5%. The results suggest that rowing involves almost every muscle in the body and that bilateral leg extension power is very important during this activity.

We evaluated the impact of bilateral leg extension power and fat-free mass on 2000 m rowing ergometer performance in 332 young oarsmen (age 21+/-2 years, height 1.76+/-0.05 m, body mass 62+/-6 kg; mean+/- s ). The 2000 m rowing performance time was correlated with height (1.62-1.93 m; R-2 = 0.23, P &lt;0.001), body mass (53-95 kg; R-2 = 0.53, P &lt;0.001), fat-free mass (47-82 kg; R-2 = 0.58, P &lt;0.001) and bilateral leg extension power (1202-3302 W; R-2 = 0.38, P &lt;0.001). Multiple regression analysis selected fat-free mass and bilateral leg extension power as regressor variables. Fat-free mass explained 58% of the variability in rowing performance and the inclusion of bilateral leg extension power improved the power of prediction by 5%. The results suggest that rowing involves almost every muscle in the body and that bilateral leg extension power is very important during this activity.

The purpose of this study was to test the hypothesis that regular exercise training in elderly people affects the type 1/type 2 balance. Nine elderly women who train by walking (mean+/-S.E.M., age 63+/-1 years, VO2 peak 32.2+/-1.0 ml kg(-1) min(-1)), 12 age-matched untrained women (63+/-1 years, 27.8+/-0.9 ml kg(-1) min(-1)), and nine young untrained women (26+/-1 years, 37.8+/-1.3 ml kg(-1) min(-1)) participated in the study. We measured interferon gamma (IFN-gamma), IL-2, and IL-4 in CD4+ and CD8+ T cells, to compare type I and type 2 T cells. The number of CD4+ cells expressing intracellular IFN-gamma (CD4+/IFN-gamma cell) significantly higher in the elderly trained than in the young (P &lt; 0.01). The number of CD8+/IL-2 cells was significantly higher in the elderly trained than in the elderly untrained (P &lt; 0.05). The number of CD8+/IL-4 cells was significantly higher in the young than in the elderly untrained (P &lt; 0.01). No significant differences were apparent in the IFN-gamma/IL-4 ratio within CD4+ and CD8+ cells from the three groups. These results might indicate that the effect of age on the balance of type 1/type 2 T cells was stronger than the effect of physical training. (C) 2003 Elsevier Ireland Ltd. All rights reserved.

The purpose of this study was to test the hypothesis that regular exercise training in elderly people affects the type 1/type 2 balance. Nine elderly women who train by walking (mean+/-S.E.M., age 63+/-1 years, VO2 peak 32.2+/-1.0 ml kg(-1) min(-1)), 12 age-matched untrained women (63+/-1 years, 27.8+/-0.9 ml kg(-1) min(-1)), and nine young untrained women (26+/-1 years, 37.8+/-1.3 ml kg(-1) min(-1)) participated in the study. We measured interferon gamma (IFN-gamma), IL-2, and IL-4 in CD4+ and CD8+ T cells, to compare type I and type 2 T cells. The number of CD4+ cells expressing intracellular IFN-gamma (CD4+/IFN-gamma cell) significantly higher in the elderly trained than in the young (P &lt; 0.01). The number of CD8+/IL-2 cells was significantly higher in the elderly trained than in the elderly untrained (P &lt; 0.05). The number of CD8+/IL-4 cells was significantly higher in the young than in the elderly untrained (P &lt; 0.01). No significant differences were apparent in the IFN-gamma/IL-4 ratio within CD4+ and CD8+ cells from the three groups. These results might indicate that the effect of age on the balance of type 1/type 2 T cells was stronger than the effect of physical training. (C) 2003 Elsevier Ireland Ltd. All rights reserved.

For older people exercise intensity is often determined based on heart rate (HR) or the percentage of maximal HR (%HRmax). This study evaluated oxygen uptake ((V) over circleO(2)) and HR during ergometry rowing (combined arm and leg; sitting exercise) and treadmill running (leg; upright exercise) for 15 older people [age, (mean +/- SD) 62 +/- 3 years]. The HR was lower during ergometry rowing than during treadmill running at a blood lactate concentration of 4 mmol 1(-1) (151 +/- 4 beat min(-1) versus 160 +/- 5 beat min(-1), P &lt; 0(.)05) and at a maximal effort (171 +/- 7 beat min(-1) versus 177 +/- 7 beat min(-1), P &lt; 0(.)05). This was the case although the (V) over circleO(2) was higher during ergometry rowing than during treamill running both at a blood lactate concentration of 4 mmol 1(-1) (3(.)0 +/- 0(.)4 l min(-1) versus 2(.)7 +/- 0(.)4 l min(-1), P &lt; 0(.)05) and at a maximal effort (3(.)4 +/- 0(.)4 l min versus 3(.)1 +/- 0(.)3 l min P &lt; 0(.)05). %HRmax and %HR reserve were lower during ergometry rowing than during treadmill running. The results suggest that, in prescription of rowing for older people, the relation between HR and (V) over circleO(2) for rowing and the attenuated HR response to rowing should be taken into consideration.

There is evidence that estrogen plays an important role in skeletal tissue in males as well as females. We have reported that phytoestrogens, such as genistein, selectively act on bone and exhibit cooperative effects on bone mass when combined with exercise in ovariectomized mice. In this study, we examined whether both interventions exhibit cooperative effects on bone loss in androgen-deficient mice similar to those in estrogen-deficient mice. Male mice aged 7 wk were either sham operated or orchidectomized (ORX) and divided into six groups: 1) sham; 2) ORX; 3) ORX and treated with genistein (0.4 mg/day) subcutaneously; 4) ORX, exercised on a treadmill daily for 30 min/day at 12 m/min; 5) ORX, given genistein, and exercised (ORX+ExG); and 6) ORX and treated with 17beta-estradiol (E-2). Four weeks after the intervention, seminal vesicle weight strikingly decreased in ORX mice, and it was not affected by administration of genistein or E-2. Bone mineral density of whole femur was significantly reduced by ORX, and bone loss was prevented by the combined intervention. Histomorphometric analysis showed that bone volume and trabecular thickness in the distal femoral cancellous bone were significantly lower in the ORX group than in the Sham group, and they were completely restored in the ORX+ExG group, as in the ORX with E-2 group. These results indicate that the combined intervention of moderate exercise and a low dose of genistein administration shows an additive effect in preventing bone loss in ORX mice similar to that in ovariectomized mice.

For older people exercise intensity is often determined based on heart rate (HR) or the percentage of maximal HR (%HRmax). This study evaluated oxygen uptake ((V) over circleO(2)) and HR during ergometry rowing (combined arm and leg; sitting exercise) and treadmill running (leg; upright exercise) for 15 older people [age, (mean +/- SD) 62 +/- 3 years]. The HR was lower during ergometry rowing than during treadmill running at a blood lactate concentration of 4 mmol 1(-1) (151 +/- 4 beat min(-1) versus 160 +/- 5 beat min(-1), P &lt; 0(.)05) and at a maximal effort (171 +/- 7 beat min(-1) versus 177 +/- 7 beat min(-1), P &lt; 0(.)05). This was the case although the (V) over circleO(2) was higher during ergometry rowing than during treamill running both at a blood lactate concentration of 4 mmol 1(-1) (3(.)0 +/- 0(.)4 l min(-1) versus 2(.)7 +/- 0(.)4 l min(-1), P &lt; 0(.)05) and at a maximal effort (3(.)4 +/- 0(.)4 l min versus 3(.)1 +/- 0(.)3 l min P &lt; 0(.)05). %HRmax and %HR reserve were lower during ergometry rowing than during treadmill running. The results suggest that, in prescription of rowing for older people, the relation between HR and (V) over circleO(2) for rowing and the attenuated HR response to rowing should be taken into consideration.

There is evidence that estrogen plays an important role in skeletal tissue in males as well as females. We have reported that phytoestrogens, such as genistein, selectively act on bone and exhibit cooperative effects on bone mass when combined with exercise in ovariectomized mice. In this study, we examined whether both interventions exhibit cooperative effects on bone loss in androgen-deficient mice similar to those in estrogen-deficient mice. Male mice aged 7 wk were either sham operated or orchidectomized (ORX) and divided into six groups: 1) sham; 2) ORX; 3) ORX and treated with genistein (0.4 mg/day) subcutaneously; 4) ORX, exercised on a treadmill daily for 30 min/day at 12 m/min; 5) ORX, given genistein, and exercised (ORX+ExG); and 6) ORX and treated with 17beta-estradiol (E-2). Four weeks after the intervention, seminal vesicle weight strikingly decreased in ORX mice, and it was not affected by administration of genistein or E-2. Bone mineral density of whole femur was significantly reduced by ORX, and bone loss was prevented by the combined intervention. Histomorphometric analysis showed that bone volume and trabecular thickness in the distal femoral cancellous bone were significantly lower in the ORX group than in the Sham group, and they were completely restored in the ORX+ExG group, as in the ORX with E-2 group. These results indicate that the combined intervention of moderate exercise and a low dose of genistein administration shows an additive effect in preventing bone loss in ORX mice similar to that in ovariectomized mice.

We have reported that strenuous physical exercise causes a decrease in protein-bound sulfhydryl groups (p-SHs), such as albumin cysteine residues, in human plasma (Inayama et al., 1996, Life Sci., 59, 573-578). We further investigated the fate of plasma protein thiols after moderate exercise. Six untrained healthy female volunteers ran for 30-min at the individual ventilatory threshold. We observed an increase in protein cysteine mixed disulfides (p-S-Cys) after running, as evidenced by reducing plasma proteins with dithiothreitol to detect the increase of cysteine, along with the concomitant decrease in p-SHs in plasma. However, plasma protein-bound glutathione (GSH) and S-nitroso-protein were undetectable before and after exercise. Test tube experiments suggest that p-S-Cys are probably formed by the hydrolysis of protein GSH mixed disulfides by gamma-glutamyltranspeptidase and peptidase, and/or by the oxidative addition of p-SHs to cystine.

We have reported that strenuous physical exercise causes a decrease in protein-bound sulfhydryl groups (p-SHs), such as albumin cysteine residues, in human plasma (Inayama et al., 1996, Life Sci., 59, 573-578). We further investigated the fate of plasma protein thiols after moderate exercise. Six untrained healthy female volunteers ran for 30-min at the individual ventilatory threshold. We observed an increase in protein cysteine mixed disulfides (p-S-Cys) after running, as evidenced by reducing plasma proteins with dithiothreitol to detect the increase of cysteine, along with the concomitant decrease in p-SHs in plasma. However, plasma protein-bound glutathione (GSH) and S-nitroso-protein were undetectable before and after exercise. Test tube experiments suggest that p-S-Cys are probably formed by the hydrolysis of protein GSH mixed disulfides by gamma-glutamyltranspeptidase and peptidase, and/or by the oxidative addition of p-SHs to cystine.

We evaluated effects of age and rowing on concentrations of lipids and lipoprotein cholesterols in the blood. Maximal oxygen uptake ((V)over dot O-2max), and concentrations of total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were measured in 17 oarsmen [mean (SD)] [age 64 (4) years, body mass 69 (6) kg] and in sedentary men [age 65 (3) years, body mass 70 (7) kg] who were matched on the basis of body size. Also the variables were obtained from young oarsmen [age 22 (2) years, body mass 70 (4) kg] and young sedentary men [age 22 (3) years, body mass 69 (7) kg]. The percentage body fat of the older oarsmen was lower than that of the older sedentary men [18 (4)% compared to 23 (4)%, P&lt;0.05], but it was similar to that of the young sedentary men [17 (4)%]. Although older oarsmen possessed a lower (V)over dot O-2max than the young oarsmen [3.0 (0.4) 1.min(-1) compared to 4.1 (0.3) 1.min(-1), P&lt;0.01], they showed a (V)over dot O-2max, similar to that of the young sedentary men [3.1 (0.5) 1.min(-1)] but a higher value than obtained from the older sedentary men [2.2 (0.3) 1.min(-1), P&lt;0.05]. Although the indices of risk factors for coronary artery disease in the older oarsmen were higher than those in the young oarsmen [LDL-C/HDL-C 1.7 (0.2) compared to 1.3 (0.4), TC/HDL-C 3.1 (0.2) compared to 2.6(0.4), P&lt;0.05], they were lower than those in both the older [2.1 (0.3), 3.6 (0.3), P&lt;0.05] and the Young sedentary men [2.1 (0.4), 3.5 (0.4), P&lt;0.05]. The results suggest that rowing is an appropriate type of exercise for the promotion of health.

We evaluated effects of age and rowing on concentrations of lipids and lipoprotein cholesterols in the blood. Maximal oxygen uptake ((V)over dot O-2max), and concentrations of total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were measured in 17 oarsmen [mean (SD)] [age 64 (4) years, body mass 69 (6) kg] and in sedentary men [age 65 (3) years, body mass 70 (7) kg] who were matched on the basis of body size. Also the variables were obtained from young oarsmen [age 22 (2) years, body mass 70 (4) kg] and young sedentary men [age 22 (3) years, body mass 69 (7) kg]. The percentage body fat of the older oarsmen was lower than that of the older sedentary men [18 (4)% compared to 23 (4)%, P&lt;0.05], but it was similar to that of the young sedentary men [17 (4)%]. Although older oarsmen possessed a lower (V)over dot O-2max than the young oarsmen [3.0 (0.4) 1.min(-1) compared to 4.1 (0.3) 1.min(-1), P&lt;0.01], they showed a (V)over dot O-2max, similar to that of the young sedentary men [3.1 (0.5) 1.min(-1)] but a higher value than obtained from the older sedentary men [2.2 (0.3) 1.min(-1), P&lt;0.05]. Although the indices of risk factors for coronary artery disease in the older oarsmen were higher than those in the young oarsmen [LDL-C/HDL-C 1.7 (0.2) compared to 1.3 (0.4), TC/HDL-C 3.1 (0.2) compared to 2.6(0.4), P&lt;0.05], they were lower than those in both the older [2.1 (0.3), 3.6 (0.3), P&lt;0.05] and the Young sedentary men [2.1 (0.4), 3.5 (0.4), P&lt;0.05]. The results suggest that rowing is an appropriate type of exercise for the promotion of health.

This study evaluated whether the heart rate (HR) response to exercise depends on body position and on the active muscle mass. The HR response to ergometer rowing (sitting and using both arms and legs) was compared to treadmill running (upright exercise involving mainly the legs) using a progressive exercise intensity protocol in 55 healthy men [mean (SD) height 176 (5) cm, body mass 71 (6) kg, age 21 (3) years]. During rowing HR was lower than during running at a blood lactate concentration of 2 mmol.l(-1) [145 (13) compared to 150 (11) beat-min(-1), P &lt; 0.05], 4 mmol.l(-1) [170 (10) compared to 177 (13) beat-min(-1), P &lt; 0.05], and 6 mmol.l(-1) [182 (10) compared to 188 (10) beat-min(-1), P &lt; 0.05]. Also during maximal intensity rowing, HR was lower than during maximal Intensity running [194 (9) compared to 198 (11) beat-min(-1), P &lt; 0.05]. These results were accompanied by a higher maximal oxygen uptake during rowing than during running [rowing compared to running, 4.50 (0.5) and 4.35 (0.4) l.min(-1), respectively, P &lt; 0.01]. Thus, the oxygen pulse, as an index of the stroke volume of the heart, was higher during rowing than during running at any given intensity. The results suggest that compared to running, the seated position and/or the involvement of more muscles during rowing facilitate venous return and elicit a smaller HR response for the same relative exercise intensity.

This study evaluated whether the heart rate (HR) response to exercise depends on body position and on the active muscle mass. The HR response to ergometer rowing (sitting and using both arms and legs) was compared to treadmill running (upright exercise involving mainly the legs) using a progressive exercise intensity protocol in 55 healthy men [mean (SD) height 176 (5) cm, body mass 71 (6) kg, age 21 (3) years]. During rowing HR was lower than during running at a blood lactate concentration of 2 mmol.l(-1) [145 (13) compared to 150 (11) beat-min(-1), P &lt; 0.05], 4 mmol.l(-1) [170 (10) compared to 177 (13) beat-min(-1), P &lt; 0.05], and 6 mmol.l(-1) [182 (10) compared to 188 (10) beat-min(-1), P &lt; 0.05]. Also during maximal intensity rowing, HR was lower than during maximal Intensity running [194 (9) compared to 198 (11) beat-min(-1), P &lt; 0.05]. These results were accompanied by a higher maximal oxygen uptake during rowing than during running [rowing compared to running, 4.50 (0.5) and 4.35 (0.4) l.min(-1), respectively, P &lt; 0.01]. Thus, the oxygen pulse, as an index of the stroke volume of the heart, was higher during rowing than during running at any given intensity. The results suggest that compared to running, the seated position and/or the involvement of more muscles during rowing facilitate venous return and elicit a smaller HR response for the same relative exercise intensity.

Exercise is known to induce the oxidation of blood low-molecular-weight (LMW) thiols such as reduced glutathione (GSH). We previously reported that full-marathon running induced a decrease in human plasma levels of protein-bound sulfhydryl groups (p-SHs). Moderate exercise, a 30-min running at the intensity of the individual ventilatory threshold, performed by untrained healthy females caused a significant decrease in erythrocyte levels of p-SHs (mostly hemoglobin cysteine residues) and LMW thiols, but their levels returned to each baseline by 2 h. No significant change in plasma LMW thiols was observed. However, plasma levels of p-SHs significantly decreased after running and remained unchanged after 24 h. These results suggest that moderate exercise causes the oxidation of blood thiols, especially protein-bound thiols. (C) 2002 Elsevier Science Inc. All rights reserved.

Exercise is known to induce the oxidation of blood low-molecular-weight (LMW) thiols such as reduced glutathione (GSH). We previously reported that full-marathon running induced a decrease in human plasma levels of protein-bound sulfhydryl groups (p-SHs). Moderate exercise, a 30-min running at the intensity of the individual ventilatory threshold, performed by untrained healthy females caused a significant decrease in erythrocyte levels of p-SHs (mostly hemoglobin cysteine residues) and LMW thiols, but their levels returned to each baseline by 2 h. No significant change in plasma LMW thiols was observed. However, plasma levels of p-SHs significantly decreased after running and remained unchanged after 24 h. These results suggest that moderate exercise causes the oxidation of blood thiols, especially protein-bound thiols. (C) 2002 Elsevier Science Inc. All rights reserved.

We evaluated the effects of rowing on the morphology and function of the leg extensor muscle in old people. The area and the power of the leg extensor muscle were measured in 15 oarsmen - age [mean (SD)] 65 (3) years
height 171 (4) cm, body mass 68 (6) kg - and in 15 sedentary men - age 66 (4) years, height 170 (4) cm, body mass 67 (7) kg - who were matched on the basis of their body size. The leg extensor muscle area of the oarsmen was larger than that of the sedentary men [77.8 (5.4) vs 68.4 (5.1) cm2, P &lt
0.05]. Also the bilateral leg extension power of the oarsmen was larger than that of the sedentary men [1,624 (217) vs 1,296 (232) W, P &lt
0.05]. Thus, the leg extension power per the leg extensor muscle area was not significantly different between two groups [20.9 (2.0) vs 19.9 (2.1) W·cm-2) and leg extension power was correlated to the leg extensor muscle area (59-89 cm 2, r = 0.74, P &lt
0.001). Also the 2,000-m rowing ergometer time of the oarsmen [495 (14) s
range 479-520 s] was related to leg extensor muscle area (68-89 cm2, r = 0.63, P &lt
0.01). The results suggest that rowing prevents age-related muscle wasting and weakness. © Springer-Verlag 2002.

We evaluated the effects of rowing on the morphology and function of the leg extensor muscle in old people. The area and the power of the leg extensor muscle were measured in 15 oarsmen - age [mean (SD)] 65 (3) years
height 171 (4) cm, body mass 68 (6) kg - and in 15 sedentary men - age 66 (4) years, height 170 (4) cm, body mass 67 (7) kg - who were matched on the basis of their body size. The leg extensor muscle area of the oarsmen was larger than that of the sedentary men [77.8 (5.4) vs 68.4 (5.1) cm2, P &lt
0.05]. Also the bilateral leg extension power of the oarsmen was larger than that of the sedentary men [1,624 (217) vs 1,296 (232) W, P &lt
0.05]. Thus, the leg extension power per the leg extensor muscle area was not significantly different between two groups [20.9 (2.0) vs 19.9 (2.1) W·cm-2) and leg extension power was correlated to the leg extensor muscle area (59-89 cm 2, r = 0.74, P &lt
0.001). Also the 2,000-m rowing ergometer time of the oarsmen [495 (14) s
range 479-520 s] was related to leg extensor muscle area (68-89 cm2, r = 0.63, P &lt
0.01). The results suggest that rowing prevents age-related muscle wasting and weakness. © Springer-Verlag 2002.

We developed an analytical method for measuring tea catechins in plasma by solid-phase extraction (SPE), followed by HPLC with a coulometric electrochemical detector. The plasma was mixed with an equal volume of acetonitrile to precipitate protein, and catechins in the resulting supernatant were extracted by SPE, using a C 18 cartridge. To correct the extraction efficiency, ethyl gallate was simultaneously added with acetonitrile as an internal standard. Plasma samples were treated in microtubes, and evaporation and SPE were performed by the use of a vacuum centrifuge and vacuum manifold for SPE. The use of these instruments allowed the handling of a large number of samples simultaneously. In this method, (-)-epicatechin (EC), (-)-epicatechin-3-O-gallate (ECg), (-)-epigallocatechin (EGC), (-)-epigallocatechin-3-O-gallate (EGCg), and ethyl gallate could be detected as a single peak with high sensitivity. For an analysis of the conjugated form of catechins, plasma samples were treated with glucuronidase and sulfatase. Type H-2 beta-glucuronidase effectively digested the conjugated forms, and the enzyme also converted EGCg and ECg to their nongallated form. When the concentrations of catechins in plasma were analyzed in subjects who took a single dose of catechin liquid, the concentration of free EGCg in plasma reached a maximum of 300 nM at 1 h after intake; those of the other free form of catechins increased only slightly after the intake. The concentration of total catechins (free+conjugated forms) in plasma increased up to 2 h after the intake.

We developed an analytical method for measuring tea catechins in plasma by solid-phase extraction (SPE), followed by HPLC with a coulometric electrochemical detector. The plasma was mixed with an equal volume of acetonitrile to precipitate protein, and catechins in the resulting supernatant were extracted by SPE, using a C 18 cartridge. To correct the extraction efficiency, ethyl gallate was simultaneously added with acetonitrile as an internal standard. Plasma samples were treated in microtubes, and evaporation and SPE were performed by the use of a vacuum centrifuge and vacuum manifold for SPE. The use of these instruments allowed the handling of a large number of samples simultaneously. In this method, (-)-epicatechin (EC), (-)-epicatechin-3-O-gallate (ECg), (-)-epigallocatechin (EGC), (-)-epigallocatechin-3-O-gallate (EGCg), and ethyl gallate could be detected as a single peak with high sensitivity. For an analysis of the conjugated form of catechins, plasma samples were treated with glucuronidase and sulfatase. Type H-2 beta-glucuronidase effectively digested the conjugated forms, and the enzyme also converted EGCg and ECg to their nongallated form. When the concentrations of catechins in plasma were analyzed in subjects who took a single dose of catechin liquid, the concentration of free EGCg in plasma reached a maximum of 300 nM at 1 h after intake; those of the other free form of catechins increased only slightly after the intake. The concentration of total catechins (free+conjugated forms) in plasma increased up to 2 h after the intake.

We reported that genistein, a soybean isoflavone, prevents bone loss caused by estrogen deficiency, without undesirable effects on the uterus. In this study, we examined cooperative effects of genistein administration and running exercise on bone mass in ovariectomized (OVX) mice. Female mice aged 7 weeks were either sham-operated or OVX and divided into six groups: (1) sham; (2) OVX; (3) OVX, treated with genistein at a submaximal dose (0.4 mg/day) subcutaneously (G); (4) OVX, exercised on a treadmill daily for 30 minutes/day at 12 m/minute on a 10 degrees uphill slope (Ex); (5) OVX, given genistein and exercised (ExG); and (6) OVX, treated with 17 beta -estradiol (0.03 mug/day) in the same manner as genistein (E-2). Four weeks after intervention, bone mass was estimated by dual-energy X-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT). Bone mineral density (BMD) of the whole femur measured by DXA was higher in both the G and the Ex groups than in the OVX group. Furthermore, BMD in the ExG group was significantly higher than that in the groups receiving either intervention alone. Bone area in distal region of the femur was significantly higher in Ex and ExG groups as compared with those in the OVX and G groups. pQCT analysis showed that the cross-sectional areas (CSAs) and periosteum perimeter at midshaft of the femur did not differ in the sham and OVX groups but were significantly higher in Ex and ExG groups. Histomorphometric analysis showed that bone formation rate/bone surface (BFR/BS) was significantly higher in both Ex and ExG groups as compared with that in non-exercised groups. The bone volume (BV/TV) in the distal femoral cancellous bone was lower in the OVX than that in the sham group, and it was restored completely in the ExG group, as in the E-2 group. Thickness of the trabecular bone (Tb.Th) was higher in Ex and ExG groups than that in the OVX and G groups. These results indicate that the combined intervention of moderate exercise and the submaximal dose of genistein administration show a cooperative effect in preventing bone loss in OVX mice.

We reported that genistein, a soybean isoflavone, prevents bone loss caused by estrogen deficiency, without undesirable effects on the uterus. In this study, we examined cooperative effects of genistein administration and running exercise on bone mass in ovariectomized (OVX) mice. Female mice aged 7 weeks were either sham-operated or OVX and divided into six groups: (1) sham; (2) OVX; (3) OVX, treated with genistein at a submaximal dose (0.4 mg/day) subcutaneously (G); (4) OVX, exercised on a treadmill daily for 30 minutes/day at 12 m/minute on a 10 degrees uphill slope (Ex); (5) OVX, given genistein and exercised (ExG); and (6) OVX, treated with 17 beta -estradiol (0.03 mug/day) in the same manner as genistein (E-2). Four weeks after intervention, bone mass was estimated by dual-energy X-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT). Bone mineral density (BMD) of the whole femur measured by DXA was higher in both the G and the Ex groups than in the OVX group. Furthermore, BMD in the ExG group was significantly higher than that in the groups receiving either intervention alone. Bone area in distal region of the femur was significantly higher in Ex and ExG groups as compared with those in the OVX and G groups. pQCT analysis showed that the cross-sectional areas (CSAs) and periosteum perimeter at midshaft of the femur did not differ in the sham and OVX groups but were significantly higher in Ex and ExG groups. Histomorphometric analysis showed that bone formation rate/bone surface (BFR/BS) was significantly higher in both Ex and ExG groups as compared with that in non-exercised groups. The bone volume (BV/TV) in the distal femoral cancellous bone was lower in the OVX than that in the sham group, and it was restored completely in the ExG group, as in the E-2 group. Thickness of the trabecular bone (Tb.Th) was higher in Ex and ExG groups than that in the OVX and G groups. These results indicate that the combined intervention of moderate exercise and the submaximal dose of genistein administration show a cooperative effect in preventing bone loss in OVX mice.

This study was performed to assess the effects of short-term, extremely high-intensity intermittent exercise training on the GLUT-4 content of rat skeletal muscle. Three- to four-week-old male Sprague-Dawley rats with an initial body weight ranging from 45 to 55 g were used for this study. These rats were randomly assigned to an 8-day period of high-intensity intermittent exercise training (HIT), relatively high-intensity intermittent prolonged exercise training (RHT), or low-intensity prolonged exercise training (LIT). Age-matched sedentary rats were used as a control. In the HIT group, the rats repeated fourteen 20-s swimming bouts with a weight equivalent to 14, 15, and 16% of body weight for the first 2, the next 4, and the last 2 days, respectively. Between exercise bouts, a 10-s pause was allowed. RHT consisted of five 17-min swimming bouts with a 3-min rest between bouts. During the first bout, the rat swam without weight, whereas during the following four bouts, the rat was attached to a weight equivalent to 4 and 5% of its body weight for the first 5 days and the following 3 days, respectively. Rats in the LIT group swam 6 h/day for 8 days in two 3-h bouts separated by 45 min of rest. In the first experiment, the HIT, LIT, and control rats were compared. GLUT-4 content in the epitrochlearis muscle in the HIT and LIT groups after training was significantly higher than that in the control rats by 83 and 91%, respectively. Furthermore, glucose transport activity, stimulated maximally by both insulin (2 mU/ ml) (HIT: 48%, LIT: 75%) and contractions (25 10-s tetani) (HIT: 55%, LIT: 69%), was higher in the training groups than in the control rats. However, no significant differences in GLUT-4 content or in maximal glucose transport activity in response to both insulin and contractions were observed between the two training groups. The second experiment demonstrated that GLUT-4 content after HIT did not differ from that after RHT (66% higher in trained rats than in control). In conclusion, the present investigation demonstrated that 8 days of HIT lasting only 280 s elevated both GLUT-4 content and maximal glucose transport activity in rat skeletal muscle to a level similar to that attained after LIT, which has been considered a tool to increase GLUT-4 content maximally.

This study was performed to assess the effects of short-term, extremely high-intensity intermittent exercise training on the GLUT-4 content of rat skeletal muscle. Three- to four-week-old male Sprague-Dawley rats with an initial body weight ranging from 45 to 55 g were used for this study. These rats were randomly assigned to an 8-day period of high-intensity intermittent exercise training (HIT), relatively high-intensity intermittent prolonged exercise training (RHT), or low-intensity prolonged exercise training (LIT). Age-matched sedentary rats were used as a control. In the HIT group, the rats repeated fourteen 20-s swimming bouts with a weight equivalent to 14, 15, and 16% of body weight for the first 2, the next 4, and the last 2 days, respectively. Between exercise bouts, a 10-s pause was allowed. RHT consisted of five 17-min swimming bouts with a 3-min rest between bouts. During the first bout, the rat swam without weight, whereas during the following four bouts, the rat was attached to a weight equivalent to 4 and 5% of its body weight for the first 5 days and the following 3 days, respectively. Rats in the LIT group swam 6 h/day for 8 days in two 3-h bouts separated by 45 min of rest. In the first experiment, the HIT, LIT, and control rats were compared. GLUT-4 content in the epitrochlearis muscle in the HIT and LIT groups after training was significantly higher than that in the control rats by 83 and 91%, respectively. Furthermore, glucose transport activity, stimulated maximally by both insulin (2 mU/ ml) (HIT: 48%, LIT: 75%) and contractions (25 10-s tetani) (HIT: 55%, LIT: 69%), was higher in the training groups than in the control rats. However, no significant differences in GLUT-4 content or in maximal glucose transport activity in response to both insulin and contractions were observed between the two training groups. The second experiment demonstrated that GLUT-4 content after HIT did not differ from that after RHT (66% higher in trained rats than in control). In conclusion, the present investigation demonstrated that 8 days of HIT lasting only 280 s elevated both GLUT-4 content and maximal glucose transport activity in rat skeletal muscle to a level similar to that attained after LIT, which has been considered a tool to increase GLUT-4 content maximally.

We investigated the influence of a single exhaustive bout of downhill running on oxidative damage to DNA and changes of antioxidant vitamin concentrations in rats. Plasma vitamin E levels were unchanged up to 48 hr postexercise. However, plasma ascorbic acid (AA) levels increased after the exercise, then decreased thereafter. This increase corresponded to a marked decrease in AA concentration in the adrenal glands. The activity of hepatic l-gulono-gamma -lactone oxidase, which catalyzes AA synthesis, was unaltered after the exercise. The weight of the adrenal glands was significantly increased 24 hr postexercise. These results indicate that the change in the plasma AA concentration after vigorous exercise was due mainly to the release of AA from the adrenal glands. The plasma creatine phosphokinase (CPK) activity and white blood cell (WBC) count increased 3 to 6 hr postexercise. Over this same period, a marker of oxidative DNA damage, 8-hydroxydeoxyguanosine in DNA, increased in the WBC, but not in the foreleg muscle. Lipid peroxide and vitamin E levels were also unchanged in the foreleg muscle. There was a positive correlation between CPK activity in the plasma and DNA damage in the WBC, suggesting that the DNA damage in the WBC was closely related with muscle damage due to exercise. (J. Nutr. Biochem. 11:401-407, 2000) (C) Elsevier Science Inc. 2000. All rights reserved.

We investigated the influence of a single exhaustive bout of downhill running on oxidative damage to DNA and changes of antioxidant vitamin concentrations in rats. Plasma vitamin E levels were unchanged up to 48 hr postexercise. However, plasma ascorbic acid (AA) levels increased after the exercise, then decreased thereafter. This increase corresponded to a marked decrease in AA concentration in the adrenal glands. The activity of hepatic l-gulono-gamma -lactone oxidase, which catalyzes AA synthesis, was unaltered after the exercise. The weight of the adrenal glands was significantly increased 24 hr postexercise. These results indicate that the change in the plasma AA concentration after vigorous exercise was due mainly to the release of AA from the adrenal glands. The plasma creatine phosphokinase (CPK) activity and white blood cell (WBC) count increased 3 to 6 hr postexercise. Over this same period, a marker of oxidative DNA damage, 8-hydroxydeoxyguanosine in DNA, increased in the WBC, but not in the foreleg muscle. Lipid peroxide and vitamin E levels were also unchanged in the foreleg muscle. There was a positive correlation between CPK activity in the plasma and DNA damage in the WBC, suggesting that the DNA damage in the WBC was closely related with muscle damage due to exercise. (J. Nutr. Biochem. 11:401-407, 2000) (C) Elsevier Science Inc. 2000. All rights reserved.

Exercise induced chromosomal damage was evaluated in trained and untrained subjects, who performed treadmill running at 85% of maximal oxygen uptake for 30 min. The subjects had their peripheral blood taken before, immediately after and 30 min after the running test for the analysis of lymphocyte chromosomal damage that was evaluated by micronucleus assay. The blood samples were also subjected to X-ray irraddiation in vitro to examine the modification of exercise induced chromosomal damage by a secondarily induced oxidative stress. Spontaneous chromosomal damage in lymphocytes did not significantly increase at least until 30 min after the running both in the trained and untrained subjects. However, the X-ray-induced chromosomal damage was significantly enhanced at 30 min after the running in the untrained group, but not in the trained group. The ratio of X-ray-induced/spontaneous chromosomal damage also tended to increase after the running only in the untrained group. These preliminary results suggest that intensive exercise induced Very slight chromosomal damage only in the untrained group. which could be intensified by the secondarily induced oxidative stress.

Exercise induced chromosomal damage was evaluated in trained and untrained subjects, who performed treadmill running at 85% of maximal oxygen uptake for 30 min. The subjects had their peripheral blood taken before, immediately after and 30 min after the running test for the analysis of lymphocyte chromosomal damage that was evaluated by micronucleus assay. The blood samples were also subjected to X-ray irraddiation in vitro to examine the modification of exercise induced chromosomal damage by a secondarily induced oxidative stress. Spontaneous chromosomal damage in lymphocytes did not significantly increase at least until 30 min after the running both in the trained and untrained subjects. However, the X-ray-induced chromosomal damage was significantly enhanced at 30 min after the running in the untrained group, but not in the trained group. The ratio of X-ray-induced/spontaneous chromosomal damage also tended to increase after the running only in the untrained group. These preliminary results suggest that intensive exercise induced Very slight chromosomal damage only in the untrained group. which could be intensified by the secondarily induced oxidative stress.

Recently (K. Kawanaka, I. Tabata, and M. Higuchi. J. Appl. Physiol. 83: 429-433, 1997), we demonstrated that glucose transport activity after repeated 10-s-long in vitro tetani in rat epitrochlearis (Epi) muscle was negatively correlated with the postcontraction muscle glycogen concentration. Therefore, we examined whether high-intensity intermittent swimming, which depletes muscle glycogen to a lower level than that observed after ten 10-s-long in vitro tetani, elicits higher glucose transport than that observed after ten 10-s-long in vitro tetani, which has been regarded as the exercise-induced maximal stimulus for glucose transport. In male rats, 2-deoxy-D-glucose transport rate in Epi muscle after eight bouts of high-intensity intermittent swimming with a weight equal to 18% of body mass (exercise duration: 20 s, rest duration between exercise bouts: 40 s) was higher than that observed after the ten 10-s-long tetani (2.25 +/- 0.08 vs. 1.02 +/- 0.16 mu mol.ml intracellular water(-1).20 min(-1)). Muscle glycogen concentration in Epi after eight bouts of high-intensity intermittent swimming was significantly lower than that observed after ten 10-s-long in vitro tetani (7.6 +/- 0.5 vs. 14.8 +/- 1.4 mu mol glucose/g muscle). These observations show that the high-intensity intermittent swimming increases glucose transport in rat Epi to a much higher level than that induced by ten 10-s-long in vitro tetani, which has been regarded as the exercise-related maximal stimulus for glucose transport. Furthermore, this finding suggests that the lower muscle glycogen level after high-intensity intermittent swimming than after in vitro tetani may play a role, because there was a significant negative correlation between glucose transport and muscle glycogen concentration in Epi after high-intensity swimming and in vitro tetani.

Recently (K. Kawanaka, I. Tabata, and M. Higuchi. J. Appl. Physiol. 83: 429-433, 1997), we demonstrated that glucose transport activity after repeated 10-s-long in vitro tetani in rat epitrochlearis (Epi) muscle was negatively correlated with the postcontraction muscle glycogen concentration. Therefore, we examined whether high-intensity intermittent swimming, which depletes muscle glycogen to a lower level than that observed after ten 10-s-long in vitro tetani, elicits higher glucose transport than that observed after ten 10-s-long in vitro tetani, which has been regarded as the exercise-induced maximal stimulus for glucose transport. In male rats, 2-deoxy-D-glucose transport rate in Epi muscle after eight bouts of high-intensity intermittent swimming with a weight equal to 18% of body mass (exercise duration: 20 s, rest duration between exercise bouts: 40 s) was higher than that observed after the ten 10-s-long tetani (2.25 +/- 0.08 vs. 1.02 +/- 0.16 mu mol.ml intracellular water(-1).20 min(-1)). Muscle glycogen concentration in Epi after eight bouts of high-intensity intermittent swimming was significantly lower than that observed after ten 10-s-long in vitro tetani (7.6 +/- 0.5 vs. 14.8 +/- 1.4 mu mol glucose/g muscle). These observations show that the high-intensity intermittent swimming increases glucose transport in rat Epi to a much higher level than that induced by ten 10-s-long in vitro tetani, which has been regarded as the exercise-related maximal stimulus for glucose transport. Furthermore, this finding suggests that the lower muscle glycogen level after high-intensity intermittent swimming than after in vitro tetani may play a role, because there was a significant negative correlation between glucose transport and muscle glycogen concentration in Epi after high-intensity swimming and in vitro tetani.

After running training, which increased GLUT-4 protein content in rat skeletal muscle by &lt;40% compared with control rats, the training effect on insulin-stimulated maximal glucose transport (insulin responsiveness) in skeletal muscle was short lived (24 h). A recent study reported that GLUT-4 protein content in rat epitrochlearis muscle increased dramatically (similar to 2-fold) after swimming training (J.-M. Ren, C. F. Semenkovich, E. A. Gulve, J. Gao, and J. O. Holloszy. J. Biol. Chem. 269, 14396-14401, 1994). Because GLUT-I protein content is known to be closely related to skeletal muscle insulin responsiveness, we thought it possible that the training effect on insulin responsiveness may remain for &gt;24 h after swimming training if GLUT-4 protein content decreases gradually from the relatively high level and still remains higher than control level for &gt;24 h after swimming training. Therefore, we examined this possibility. Male Sprague-Dawley rats swam 2 h a day for 5 days with a weight equal to 2% of body mass. Approximately 18, 42, and 90 h after cessation of training, GLUT-I protein concentration and 2-[1,2-H-3]deoxy-D-glucose transport in the presence of a maximally stimulating concentration of insulin (2 mU/ml) were examined by using incubated epitrochlearis muscle preparation. Swimming training increased GLUT-4 protein concentration and insulin responsiveness by 87 and 85%, respectively, relative to age-matched controls when examined 18 h after training. Forty-two hours after training, GLUT-4 protein concentration and insulin responsiveness were still higher by 52 and 51%, respectively, in muscle from trained rats compared with control. GLUT-4 protein concentration and insulin responsiveness in trained muscle returned to sedentary control level within 90 h after training. We conclude that 1) the change in insulin responsiveness during detraining is directly related to muscle GLUT-4 protein content, and 2) consequently, the greater the increase in GLUT-4 protein content that is induced by training, the longer an effect on insulin responsiveness persists after the training.

After running training, which increased GLUT-4 protein content in rat skeletal muscle by &lt;40% compared with control rats, the training effect on insulin-stimulated maximal glucose transport (insulin responsiveness) in skeletal muscle was short lived (24 h). A recent study reported that GLUT-4 protein content in rat epitrochlearis muscle increased dramatically (similar to 2-fold) after swimming training (J.-M. Ren, C. F. Semenkovich, E. A. Gulve, J. Gao, and J. O. Holloszy. J. Biol. Chem. 269, 14396-14401, 1994). Because GLUT-I protein content is known to be closely related to skeletal muscle insulin responsiveness, we thought it possible that the training effect on insulin responsiveness may remain for &gt;24 h after swimming training if GLUT-4 protein content decreases gradually from the relatively high level and still remains higher than control level for &gt;24 h after swimming training. Therefore, we examined this possibility. Male Sprague-Dawley rats swam 2 h a day for 5 days with a weight equal to 2% of body mass. Approximately 18, 42, and 90 h after cessation of training, GLUT-I protein concentration and 2-[1,2-H-3]deoxy-D-glucose transport in the presence of a maximally stimulating concentration of insulin (2 mU/ml) were examined by using incubated epitrochlearis muscle preparation. Swimming training increased GLUT-4 protein concentration and insulin responsiveness by 87 and 85%, respectively, relative to age-matched controls when examined 18 h after training. Forty-two hours after training, GLUT-4 protein concentration and insulin responsiveness were still higher by 52 and 51%, respectively, in muscle from trained rats compared with control. GLUT-4 protein concentration and insulin responsiveness in trained muscle returned to sedentary control level within 90 h after training. We conclude that 1) the change in insulin responsiveness during detraining is directly related to muscle GLUT-4 protein content, and 2) consequently, the greater the increase in GLUT-4 protein content that is induced by training, the longer an effect on insulin responsiveness persists after the training.

We improved the analytical method for the detection of ascorbic acid in plasma by high-performance liquid chromatography (HPLC) with an electrochemical detector (ECD) to be more selective and rapid than the protocol previously used. Main improvements are as follows. Applied potential of ECD to obtain the maximal response for ascorbic acid was +450 mV versus Ag/AgCl, but it was reduced to +350 mV. In that condition, uric acid did not respond to ECD, and only ascorbic acid was detected. EDTA contained in sample extraction/stabilizing solution gave the peak after the ascorbic acid. The addition of EDTA (0.2 mM) to the mobile phase eliminated the EDTA peak. These two improvements gave the chromatogram in which the peak that appeared from the plasma sample was only ascorbic acid, and shorten the sample run time. Ascorbic acid in plasma was unstable even though the plasma was treated with methanol/EDTA: it decreased from 1.5h at 4 degrees C. However, the treated sample, which was placed at -14 degrees C until the analysis was performed, gave the reliable ascorbic acid value at least up to 6h. The data obtained from the HPLC-ECD method was consistent with those from the hydrazine method.

We improved the analytical method for the detection of ascorbic acid in plasma by high-performance liquid chromatography (HPLC) with an electrochemical detector (ECD) to be more selective and rapid than the protocol previously used. Main improvements are as follows. Applied potential of ECD to obtain the maximal response for ascorbic acid was +450 mV versus Ag/AgCl, but it was reduced to +350 mV. In that condition, uric acid did not respond to ECD, and only ascorbic acid was detected. EDTA contained in sample extraction/stabilizing solution gave the peak after the ascorbic acid. The addition of EDTA (0.2 mM) to the mobile phase eliminated the EDTA peak. These two improvements gave the chromatogram in which the peak that appeared from the plasma sample was only ascorbic acid, and shorten the sample run time. Ascorbic acid in plasma was unstable even though the plasma was treated with methanol/EDTA: it decreased from 1.5h at 4 degrees C. However, the treated sample, which was placed at -14 degrees C until the analysis was performed, gave the reliable ascorbic acid value at least up to 6h. The data obtained from the HPLC-ECD method was consistent with those from the hydrazine method.

Vitamin D deficiency is highly prevalent in our study sample.In a cross-sectional study, we found that objectively measured physical activity and VO2max are independently and positively related to serum vitamin D status. Twelve months supplementation significantly improved 25(OH)D status in the vitamin D group compared to no changes in the Placebo group. However, the increase in 25(OH)D concentration in the vitmin D group did not result in signifi cant increases in VO2max

本研究は、持久性アスリートが経験的に実施しているテーパリングが科学的根拠に基づく手法であることを明らかとするために、テーパリングと骨格筋エネルギー生産系との関連性について検証することを目的としている。研究開始初年度である本年は、実験動物を用いてテーパリングが持久力および骨格筋エネルギー生産系に及ぼす影響を検討した。
実験にはSprague Dawley系雌ラットを用い、コントロール群、運動継続群およびテーパリング群の3群を設けた。運動継続群には9週間のトレッドミル運動を、テーパリング群には7週間の運動後に運動時間を半減させたトレッドミル運動を2週間負荷した。実験期間終了後、持久力を測定するために疲労困憊運動を実施し、その直後に解剖して各エネルギー生産系酵素の評価を実施した。
実験の結果、テーパリング群の運動継続時間はコントロール群と比較して有意に高い値を示した一方で、運動継続群とテーパリング群との間に有意な差は認め

【対象と方法】対象は長距離走鍛錬者8名(年齢21.4±1.3歳、身長171.6±6.1cm、体重56.7±8.5kg)であった。プレ実験で身体測定、座位安静時代謝測定、トレッドミルランプ負荷法での運動負荷試験を行い、ピーク時酸素摂取量(VO2peak)、最大脂質酸化量（MFO）、最大脂質酸化量時運動強度（Fatmax）を測定した。本実験で65％VO2peakで30分間あるいはFatmaxで運動中エネルギー消費量が等しく揃う時間、トレッドミル運動負荷を行い、その後2時間座位安静とした（回復期）。運動前から回復期まで呼気ガス分析を行い、総脂質酸化量等を求めた。運動前、運動中止直後、中止30分後、1時間後、2時間後に採血を行い、脂質酸化関連物質を測定した。【結果】Fatmaxは40％VO2peak前後であった。運動中および運動後のエネルギー消費量に試行間で有意差はなかった。運動中の総脂質酸化量はFatmax試行の方が65％VO2peak試行よりも有意に多く(Fatmax試行：15.6±5.1g、65％VO2peak試行：8.0±3.4g)、回復期総脂質酸化量は試行間に差

The present study found that rope skipping exercise is effectively induce anorexia, and moreover this greater exercise-induced reduction in appetite may not be strongly affected by plasma acylated ghrelin and peptide-YY concentrations in rope skipping exercise with up-and-down motions of center of mass compared without ups and downs. In addition, we observed that decreased appetite after rope skipping in women rapidly recovers compared with that of men. These results may be an evidence of exercise prescription for preventing and improving obesity in considerations of sex and exercise modes

Vitamin D deficiency is highly prevalent in our study sample.In a cross-sectional study, we found that objectively measured physical activity and VO2max are independently and positively related to serum vitamin D status. Twelve months supplementation significantly improved 25(OH)D status in the vitamin D group compared to no changes in the Placebo group. However, the increase in 25(OH)D concentration in the vitmin D group did not result in signifi cant increases in VO2max.

The present study found that rope skipping exercise is effectively induce anorexia, and moreover this greater exercise-induced reduction in appetite may not be strongly affected by plasma acylated ghrelin and peptide-YY concentrations in rope skipping exercise with up-and-down motions of center of mass compared without ups and downs. In addition, we observed that decreased appetite after rope skipping in women rapidly recovers compared with that of men. These results may be an evidence of exercise prescription for preventing and improving obesity in considerations of sex and exercise modes.

The peroxisome proliferator-activated receptor gamma 2(PPARγ2) genotypes are related to obesity and the metabolic syndrome(MetS). A low level of cardiorespiratory fitness is also a strong determining factor in the development of MetS. This cross-sectional study was performed to investigate the influence of the interaction between the PPARγ2 genotype and cardiorespiratory fitness on the risk of MetS. Healthy Japanese men(n=211) and women(n=505) participated in this study. All subjects were divided into 8 groups according to sex, fitness level(high and low fitness groups), and age(younger, age<40 years and middle-aged/older, age. 40 years). The PPARγ2 genotypes(Pro12Ala and C1431T) were analyzed by using real-time PCR with Taq-Man probes. Two-way ANCOVA with adjustment for age as a covariate indicated that fitness and the CC genotype of C1431T in the PPARγ2 gene interacted to produce a significant effect on MetS risk in younger men and that the risk of MetS in the CC genotype group with low cardiorespiratory fitness was significantly higher than that in the corresponding CT+TT genotypes or in the high fitness groups. There was no significant interaction between fitness and genoty

We carried out body composition, exercise stress test including expiration gas analysis and blood biochemical test on 36 pairs of mother and her offspring, and examined the relationship with body composition, exercise capacity and lipid metabolism between mother and offspring. We revealed the relationship concerning possession of abdominal obesity and insulin resistance, but did not reveal the correlation of serum lipid value and fasting plasma glucose between mother and her offspring. It is supposed that it is necessary for the child to take care of the improvement of life-style because the factor of falling metabolic syndrome(for example, insulin resistance) is recognized, but the child does not quite fall metabolic syndrome in the elementary school.

The aim of this study was to determine 1) relationship between cardiorespiratory fitness and central arterial viscoelasticity, and 2) effect of aerobic training on central arterial viscoelasticity. In first study, age-associated increase in central arterial viscosity was suppressed by maintenance of cardiorespiratory fitness. However, in second study, when performing 10-week aerobic training, the central arterial viscosity was not changed by the training. Therefore, this study suggests that the improvement of central arterial viscosity may need relative longer term of aerobic exercise, but shorter such a 10-week.

The purpose of this study is to determine the physical, physiological, and biochemical effects of resistance training in middle-aged women. The results of resistance training was compared with another different training modes, such as jogging/running, swimming, and tennis. Furthermore, middle-aged and young non-exercise women took part in the controls. Each subject completed their food records and caloric and major nutrient intakes were estimated.
Serum high-density lipoprotein cholesterol (HDL-C) levels was significantly higher in female endurance runners than in equal groups of female resistive trainers and sedentary female controls. Resistive trainers and controls showed no significant differences in HDL-C. No significant dose-response relationships were found for either runners or resistive trainers when daily training duration, weekly training frequency, and weekly mileage were correlated with HDL-C. It was concluded that HDL-C levels in females are associated with specific training methods.
The results of this study indicate that mean bone formation values were significantly less in the swimming group than in the resistive trained and jogging/running groups. The results also

中高年マスターズランナーの呼吸循環機能に関するフォローアップスタデイを実施した。対象者は、男性では1回目の検査時に40以上60歳以下の中年(n=12,M>40)、60歳以上65歳以下(n=9,M>60)、及び65歳以上の高齢者(n=8,M>65)、女性では35歳以上の閉経前の中年(n=6,F-Pre)と閉経後の中高年者(n=8,F-Post)である。男性ランナーは6.5〜8年、女性ランナーは約5年経過した時点で再検査を行い、Vo2max(ml/kg/min),HRmax(beat/min),02pulse(ml/kg/beat)の加齢変化を検討した。男女とも身体的特徴には変化は認められなかった。
男性ランナーにおいては、トレーニング距離の変化は、M>40:55±35→46±28km/wk,M>60:47±23→38±27km/wk,M>65:47±17→40±12km/wkであった。Vo2maxの変化はM>40:53.9±7.3→49.5±4.8(DELTAVo2max:0.58±0.52ml/kg/min/yr),M>60:50.2±4.5→43.8±4.5ml/kg/min(DELTAVo2max:0.96±0.56),M>65:46.5±3.9→42.0±4.2ml/kg/min(DELTAVo2max:0.78±0.40)であった。心拍数の変化はM>40:180±9→174±12bpm,M>60:169±8→167±6bpm,M>65:171±12→167±11bpmであった。02pulseの変化はM>40:0.30±0.04→0.29±0.03,M>60:0

In the present study, we examined whether glucose transporter in rat skeletal muscle (GLUT4) plays an important role in the process of muscle glycogen resynthesis after endurance exercise followed by glucose ingestion. Glycogen concentration in soleus muscle decreased by 25% in response to 120-min treadmill running. and increased by 100% 3 hours after glucose ingestion immediately after exercise. Muscle glycogen decreased to the level of pre-exercise state 24 hours after exercise. No significant changes were observed in GLUT4 concentration in soleus muscle during recovery period of 120-min exercise. An exhaustive running (@5.5 hours) induced significant decrease in glycogen concentration of soleus muscle, but 2-fold of muscle glycogen concentration was observed 24 hours after the exercise. GLUT4 in soleus decreased by 30% immediately after the exhaustive running, but recovered to the pre-exercise level. These results suggest that GLUT4 does not play an important role to modulate an increase of glucose uptake after endurance exercise followed by glucose ingestion.

This study was undertaken to determine if aging musele adapts to endurance training with an enhancement of mitochondrial oxidative enzyme activities and of enzymatic defenses against free radical damage by using senescent accelerated mice (SAM). A program of 8 week endurance running induced 30-40% increases in citrate synthase and 3-OH acyl CoA debydrogenase acvitities in leg muscles of either SAM-P/2 strain or SAM-R mice aged 6 and 10 months. The training also resulted in 20-30% increases in mitochondrial superoxide dismutase activities in leg muscle of different age-groups. These findings suggest that aging does not result in a progressive impairment in the ability for increasing the oxidative enzymes and free radical scavenging enzyme in muscle mitochondria in response to chronic endurance exercise in healthy mice.

The peroxisome proliferator-activated receptor gamma 2(PPARγ2) genotypes are related to obesity and the metabolic syndrome(MetS). A low level of cardiorespiratory fitness is also a strong determining factor in the development of MetS. This cross-sectional study was performed to investigate the influence of the interaction between the PPARγ2 genotype and cardiorespiratory fitness on the risk of MetS. Healthy Japanese men(n=211) and women(n=505) participated in this study. All subjects were divided into 8 groups according to sex, fitness level(high and low fitness groups), and age(younger, age<40 years and middle-aged/older, age. 40 years). The PPARγ2 genotypes(Pro12Ala and C1431T) were analyzed by using real-time PCR with Taq-Man probes. Two-way ANCOVA with adjustment for age as a covariate indicated that fitness and the CC genotype of C1431T in the PPARγ2 gene interacted to produce a significant effect on MetS risk in younger men and that the risk of MetS in the CC genotype group with low cardiorespiratory fitness was significantly higher than that in the corresponding CT+TT genotypes or in the high fitness groups. There was no significant interaction between fitness and genoty

The aim of this study was to determine 1) relationship between cardiorespiratory fitness and central arterial viscoelasticity, and 2) effect of aerobic training on central arterial viscoelasticity. In first study, age-associated increase in central arterial viscosity was suppressed by maintenance of cardiorespiratory fitness. However, in second study, when performing 10-week aerobic training, the central arterial viscosity was not changed by the training. Therefore, this study suggests that the improvement of central arterial viscosity may need relative longer term of aerobic exercise, but shorter such a 10-week

The purpose of this study was to describe the relationships among energy expenditure in daily living, leg extensor power, and lactate threshold (LT) to clear the physical fitness level necessary for independent life in older people. The subjects of this study were 25 volunteers (6 maled and 19 females).healthy and living independently. Their mean age was 67 years (range from 60 to 79 years).(1) Relationship between daily physical activity level and physical fitnessIt is proved that the activity level of dily living in elderly people is low and most of walking of dily living are intermittent. Daily energy expenditure correlated positively with LT and leg extensor power. It is concluded that elderly people who maintain a physically active life-style do not experience the decline in aerobic work capacity and muscle function (leg extensor power) in elderly people.(2) Effect of daily physical activity on physical fitnessWe examined the change of led extensor power, LT and pedometer score (number of steps) to ascertain the change of physical fitness which are influenced by a change of physiological function by ageing or daily physical activity. Leg extansor power, LT and pedometer score

We studied antioxidative function in response to exercise by using animal and humans. In animal studies. we observed increased level of lipid peroxide in plasma and skeletal muscle after 90-min swimming exercise, and lower level of plasma vitamin C was observed rats one day after swimming. One bout of down-hill running in rats induced higher increase of plasma CPK activity with higher level of plasma lipid peroxide, and although plasma CPK activity returned to the resting level 48 hr after tunning, plasma antiocidant vitamines remained to the lower level compared with pre-exercise state. We evaluated DNA damage induced by one bout or repeated bouts of vigorous exercise in trained and untrained men. Spontaneous DNA damage in lymphocytes did not increase until 30 min after one bout of vigorous running in both trained and untrained men. The trained subjects had higher spontaneous DNA damage in lymphocytes and higher plasma CPK activity at the resting stale. The spontaneous DNA damage showed significant posotive correlation with plasma CPK activity, indicating that oxidative DNA damage in lymphocytes could be occured by extensive exercise, and might be closely associated with muscle da

従来、筋運動による糖代謝機能の向上は、いわゆる低強度・長時間運動により増加すると考えられ、マラソンの競技の競技成績向上のために行うグリコーゲンロ-ディング中の運動のほとんどが、低強度・長時間運動であった。しかし、試験管内の実験では、電気刺激による短時間の等尺性筋活動によっても骨格筋の糖代謝機能が長時間運動と同程度に増加することが知られており、高い強度の運動でも糖代謝機能が増加する可能性が示唆されていた。もし、試合直前にグリコーゲンロ-ディングのために、長時間におよぶ低強度運動ばかりではなく、より高い強度の運動を短い時間行うことにより筋の糖代謝能が充分高まることが理論的に明らかになれば、マラソン選手等も通常のトレーニングメニューを変えることなく試合前の練習を行うことができ、選手の負担も低減する。そこで本研究では、高強度・短時間運動が糖代謝機能に及ぼす影響を明らかにすることを目的に、ラットに短時

The factors such as lean body mass(LBM), hormonal status, energy balance, previous physical activity has been shown to influence energy metabolism. This study investigated 1) basal metabolic rate(BMR) in 32 elite long distance runners, 11 rowers and 21 sedentary controls, and 2) the effect of body composition, nutritional status, menstrual status on BMR. BMR was significantly higher in rowers(1346±195kcal/day) than in runners(1205±152kcal/day) and sedentary(1207±158/day). But BMR per LBM did not differ significantly among three groups. Body weight, LBM, and energy intake were highly correlated with BMR (p<0.01). BMR in the runners who has athletic menstrual dysfunction was significantly lower than in eumenorrheic runners (1280±143 vs. 1171±146, p<0.05). The daily caloric intakes of amenorrheic and oligomenorrheic runners was lower than in eumenorrheic runners. These results suggest that a lower BMR is one mechanism that contributes to weight maintenance in amenorrheic and oligomenorrheic runners

Body fat accumulation and bone loss are both often associated with estrogen deficiency following menopause. In this study, we examined whether soy isoflavone, one of the phytoestrogens, and moderate exercise interventions exhibit cooperative effects on body composition and bone mass in ovariectomized (OVX) mice. Eight week-old female mice were assigned to six groups : (1)sham-operated (sham) ; (2)OVX ; (3)OVX with received a soy isoflavone diet (OVX+ISO) ; (4)OVX with exercised on a treadmill (OVX+EX) ; (5)OVX with given both isoflavone and exercise (OVX+ISO&EX) ; and (6)OVX with treated with 17 β-estradiol subcutaneously (OVX+E2). Body composition and bone mineral density (BMD) were estimated by dual-energy X-ray absorptiometry (DXA). After the 6-week intervention, whole body fat (%) in the OVX group showed significantly higher than that in the sham group. Intervention of exercise and isoflavone alone partially inhibited OVX-induced body fat gain, and the combined intervention as well as E2 treatment completely restored fat mass to the sham level. Lean body mass in the whole body was not different in OVX group compared with that in OVX+ISO, OVX+EX and OVX+E2 groups, but it was si

We evaluated effects of age and rowing on cardiovascular function, blood lipid-lipoprotein profile and muscle mass. Although older oarsmen possessed a lower Vo2max than the young oarsmen, they showed a Vo2max similar to that of the young sedentary men but a higher value than obtained from the older sedentary men. The index of risk factors for CHD in the older oarsmen (LDL-C/HDL-C) was lower than that in the sedentary older men. The results suggest that rowing is an appropriate type of exercise for the promotion of health.We also evaluated the effects of rowing on the morphology and function of the leg muscle in older people. The leg extensor muscle area (CSA) of the oarsmen was larger that that of the sedentary men. Also the bilateral leg extension power of the oarsmen was larger than that of the sedentary men. Thus, the leg extensor power per CSA was not different between the two groups. The results suggest that rowing prevents age-related muscle wasting and weakness.This study evaluated oxygen uptake (Vo2) and heart rate (HR) during ergometry rowing (combined arm and leg ; sitting exercise) and treadmill running (leg ; upright exercise) for older people. The HR was lower during e

The purpose of this study was to determine the effect of high fat diet on glycogen loading in rats, Male Wistar rats were assigned to low fat diet (13% calories as fat) and a high fat diet (60% calories as fat). They ate their diets ad libitum for 5 weeks, After an overnight fast, both groups were exercised by using a two hours swimming protocol to deplete muscle glycogen. After the swimming, rats were given a high carbohydrate diet and 5% sucrose solution ad libitum. Rats were anesthetized with pentobarbital sodium, and the triceps and vastus lateralis muscles were dissected out before, immediately after, 4h after and 24h after exercise. Epididymal fat pad weight, plasma triglyceride and free fatty acids were significantly (P<0.001) higher in the high fat diet group than in the low fat group, Although the high fat diet decreased muscle glycogen concentration before exercise, the high fat diet induced increases in citrate synthase and 3-hydroxyacyl CoA dehydogenase activities, Glycogen concentration in both groups were depleted immediately after the exercise and recovered to normal level 24h after exercise. These results suggest that long term feeding of high fat diet harm the effe

Little information is available regarding the relationships among human obesity-related genes, cardiorespiratory fitness and metabolic syndrome (MS) or predisposition to MS (MP). The purpose of this study was to investigate the contribution of obese-related genes and cardiorespiratory fitness to the MS in middle-aged and old men and women. Seven hundred fifty eight healthy men and women participated in this study. We measured maximal oxygen uptake (VO2max) during an incremental cycle ergometer exercise test. Serum BDL-cholesterol, triglyceride and plasma glucose levels were measured in all subjects. Total and regional lean soft tissue and fat mass were also measured by dual-energy X-ray absorptiometry (DXA). We analysed the genotype of b3-adrenergic receptor (ADRB3 64 T>A), peroxisome proliferator-activated receptor gamma (PPARG 1431 C>. Pro12Ala), uncoupling protein 1(UCP1 3826 A>G), and fatty acid-binding protein 2(FABP2 54 A>T) using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. Significant associations were observed between VO2max less than 32 nil/kg/min in men and 30 ml/kg/min in women and increases in the number of risk factors of MS (

This study was designed to observe physiological response during one bout of high-intensity intermittent short time rowing exercise and to evaluate the effect of repeated bouts of the exercise on rowing performance for college oarsmen.The high-intensity, intermittent exercise consisted of either five or eight bouts of 20-sec rowing with the maximal effort of the subjects, and each bout was separated by 10-sec rest. In the first experiment, subjects reached to the maximal level of VO_2 and heart rate at the fourth set during both 5- and 8- sets of high-intensity, intermittent exercises. However, blood lactate concentration after high-intensity, intermittent exercise was significantly lower in the 5-set protocol than in the 8-set protocol (9.0±1.2vs. 11.3±1.6mM, p<0.05), suggesting that the 8-set protocol is much vigorous and better than the 5-set protocol as high-intensity, intermittent rowing exercise for rowers. In the 6-week rowing training, low frequency group (LF: 2 times/week) markedly improved their rowing performance (Δ3.2±1.9sec/1000m, Δ8.4±5.5sec/2000m time trials), whereas high frequency group (HF: 5 times/week) improved only in 1000m trial (Δ4.5±2.3sec).Bowers pe

Rowing exercise is a safe and efficient exercise for health promotion in elderly people. The purpose of this study was to evaluate the effects of rowing exercise on psoas major muscle size and walking ability in elderly people. The data lead us to conclude that the rowing exercise using by both rowing ergometer and exercise resistance tube is a valuable tool for increasing psoas major and thigh muscle size. Further studies are needed to confirm the effect of rowing exercise on walking ability

本研究は、加齢やトレーニング様式といった身体および動脈や静脈の硬化度といった心血管の特性が浸水時の心血管応答に及ぼす影響について検討し、浸水時の心血管応答の規定因子を決定することを目的とした。被験者は定期的な運動習慣のない若年男性11名(22.0±1.0歳)、習慣的に持久的トレーニングを行っている若年男性15名(21.0±1.5歳)、習慣的にウェイトトレーニングを行っている若年男性12名(20.7±2.2歳)の計38名の若年男性(21.2±1.7歳)、さらに心血管疾患を有さない健康的な高齢男性20名(65.1±3.2歳)であった。水温(29.5±0.2℃)の環境下において、各自の剣状突起に合わせた水位で3分間浸水し、3分目に心拍数(HR)と血圧を計測した。また事前に陸上にて、静脈血管容量、静脈コンプライアンス、動脈の硬化度(CAVI)、動脈圧受容器反射感受性(BRS)、最大酸素摂取量(VO2max)、下腿骨格筋断面積を測定した。静脈血管容量および静脈コンプライアンスは、プレチスモグラフィー法によって評価した。動脈の硬化度の評価には、Cadio-ankle vascular index法を用いた。動脈圧受容器反射感受性は、バルサルバ中の心電図のRR間隔とフィナプレスで連続的に測定された収縮期血圧の関係から算出された。VO2maxは、自転車エルゴメーターにおいて漸増負荷運動中の酸素摂取量を測定することで得られた。下腿断面積は、磁気共鳴装置によって評価された。浸水に伴うHRの低下量は高齢者に比べて若年者で有意に高値を示した。重回帰分析により、浸水に伴うHRの低下量には年齢(β=0.16)、VO2max(β=－0.04)、BRS(β=－0.04)が総合的に関連していた。浸水に伴う収縮期血圧(SBP)の増加量は若年者に比べて高齢者で有意に高値を示した。重回帰分析により、浸水に伴うSBPの上昇には年齢(β=－0.62)、安静時の平均血圧(β=0.40)、CAVI(β=0.64)が独立して関係していることが明らかとなった。これらの結果は、浸水に伴う心拍数および血圧の応答に対して、心拍出量を規定する静脈容量や静脈硬化度は関与せず、加齢、安静時血圧および動脈スティフネスなどの動脈特性および心肺体力といった身体特性が影響を及ぼすことを示唆している。今後は、運動時の心拍や血圧応答の規定因子を探索する必要があるだろう。

　本研究課題は、体重制限がないコンタクトスポーツ系選手において、体重増加が三つのテーマ（①エネルギーバランスの調節、②パフォーマンスの向上、③生活習慣病リスクの進展）に及ぼす影響を解明することを目的とした。今年度はその中でも、テーマ①として体重増加に伴う身体組成の変化が内臓量と基礎代謝量へ及ぼす影響と、テーマ③としてスポーツ選手の身体的特性と生活習慣病リスクの把握、および体重増加が生活習慣病リスクに及ぼす影響の解明を行った。　今年度は、横断研究に加えて2010年度開始の縦断研究を行い、本学米式蹴球部および運動習慣のない学生計53名を対象とし、身体組成、基礎代謝量、体力、血圧、採血による一般生化学的指標、身体活動量や栄養摂取量の測定評価を行った。テーマ①の研究においては、米式蹴球部１年生の１年間で9.0kgの体重増加に伴い、骨格筋重量が31.7±3.0kgから34.2±3.6kg、心臓重量が0.26±0.07kgから0.29±0.06kg、腎臓重量が0.34±0.03kgから0.37±0.05kgと有意に増加した。基礎代謝量においては有意な増加が認められた（Pre：1646±120kcal/day、Post:1723±189kcal/day）。しかし、肝臓重量に有意な増加は見られなかった。肝臓および、腎臓の増加量と基礎代謝量に有意な相関関係（⊿肝臓：r=0.630、P<0.05、⊿腎臓：r=0.655、P<0.05）が認められたことから、基礎代謝量の増加には、肝臓および腎臓の重量の変化が関係していること明らかになった。そして重回帰分析より、基礎代謝量の増加には特に腎臓重量の増加が及ぼす影響が大きいことが示唆された。　本研究テーマの成果として、2011年度第62回日本体育学会にてポスター発表を行った。また、2012年度European College of Sports Scienceの第17回学会において発表を行うため抄録を提出済みであり、現在本研究テーマで論文を執筆中である。また、テーマ③の研究により、米式蹴球部選手の中でも特に体格の大きさを求められるライン選手は、他のポジションの選手に比べ有意に体脂肪率が高く内臓脂肪断面積が多く、インスリン抵抗性も高いことが判明した。また米式蹴球部１年生において１年間の体重増加に伴い、内臓脂肪断面積が33.1±11.4 cm2から70.5±28.0 cm2、収縮期血圧が116.3±8.3mmHgから130.3±10.4mmHg、拡張期血圧が61.8±5.6 mmHgから69.2±9.0mmHgと有意に増加したが、インスリン抵抗性は有意に増加しなかった。以上のように、全体として悪化した指標はあったものの、選手の生活習慣病リスクは低かった。　本研究テーマの成果においては、2011年度第5回Asia-Pacific Conference on Exercise and Sports Scienceにて口頭発表を行った。また現在論文執筆中であり、2012年度中に投稿および受理を目指す。

　近年、持久的な運動能力に深く関係している骨格筋のミトコンドリアが、高脂肪食を摂取することで増加することが報告され、骨格筋のミトコンドリアの増加に、食事から摂取する脂肪が重要な役割を担っていることが明らかとなっている。そこで、我々は、実験動物を用いて、体脂肪の蓄積を伴わずに骨格筋のミトコンドリアを増加させ、持久的運動パフォーマンスを高めることができる最適な脂肪の摂取量を検討することを目的として研究を行った。課題1：異なる脂質濃度の食餌摂取が体組成及び骨格筋ミトコンドリア酵素活性に及ぼす影響　SD系の雄性ラットを低脂肪食(エネルギー比：12.5％)群、普通食(25％)群、高脂肪食(40％)群及び超高脂肪食(60％)群に分け、それぞれの食餌を4週間摂取させた。　4週間の食餌介入の結果、低脂肪食(12.5％)群と比較して超高脂肪食(60％)群の体重当たりの内臓脂肪重量は有意に高い値であった。60％群の3-ヒドロキシアシルCoA脱水素酵素活性は、12.5及び25％群と比較して有意に高い値であった。40％群の3-ヒドロキシアシルCoA脱水素酵素活性は12.5％と比較して、高い傾向が観察された。課題2：異なる脂質濃度の食餌摂取が持久的運動パフォーマンスに及ぼす影響　研究課題2では、実際にラットに走行運動を行わせ、4週間の異なる脂質濃度の食餌摂取がラットの持久的運動パフォーマンスに及ぼす影響を検討した。　40及び60％群の疲労困憊にいたるまでの走行時間は、12.5及び25％群と比較して有意に高い値であった。脂質エネルギー比が60％の食事は競技者の食事に導入するには難しいものの、本研究結果から、脂質エネルギー比が40％の食事であっても持久的パフォーマンスを向上させる可能性が示唆された。

ボート競技とは、全身の筋力・持久力を必要とするミドルパワー系競技であり、その競技時間が2000mレースの場合、世界的なトップレベルの選手で数分～数十分にわたることから、これまでのローイング・トレーニングの多くは、持久力強化を目的とした有酸素性トレーニングが主であった。一方、数十秒の高強度ローイングもトレーニングとして行われてきたが、インターバルが比較的長いトレーニングであった。スピードスケート選手が取り入れてきた高強度・間欠的トレーニングは、ミドルパワー系パフォーマンスの要因である有酸素性と無酸素性の能力を向上させることが知られている。　本研究では、このスピードスケートのトレーニング法がローイングにも適応できるかどうかを明らかにすることを目的として、短期間の高強度・間欠的トレーニングが、生体内の生理学的指標に影響を与え、持久性能力要素（VO2など）を向上させることで、ローイング・パフォーマンスの向上に有効なのではないかという仮説を立てて、6週間に及ぶ断続的な高強度・間欠的トレーニング（週3回）を実施し、エルゴメータによるローイング・パフォーマンスや生理学的指標に与える影響、トレーニング最中・直後の生化学的状態を観察した。本研究で行った『高強度・間欠的トレーニング』とは、（ローイング・エルゴメータによる20秒間の全力漕ぎ＋10秒間のインターバル）×8セットという、計230秒のトレーニングである。　被験者は早稲田大学漕艇部員18名（男：12名、女：6名）で、男子6名・女子3名ずつになるようにトレーニング群（T-群）とコントロール群（C-群）とに無作為に振り分けた。T-群には、計17回(6週間)の高強度・間欠的トレーニングを行ってもらった。C-群には、T-群が高強度・間欠的トレーニングで消費するのと同程度のエネルギーをローイングエルゴメータによる有酸素運動で消費してもらった。　その結果、①6週間のトレーニング期間を前期・中期・後期に分類した上で、それぞれの期間におけるT-群のトレーニング時の運動量（W）を比較したところ、後期の運動量は前期・中期に比べて有意に高かった。②トレーニング期間前後に行ったT-群のVO2max測定において、トレーニング後の乳酸値は、トレーニング前に比べて有意に高かった。③トレーニング後の2000mの記録の1500m～2000m区間のラップタイムにおいて、T-群はC-群に比べて有意に好タイムを記録した。　6週間に及ぶ高強度・間欠的トレーニングによって、潜在能力のより多くを出し切ることが助長され、ローイング・パフォーマンスに有酸素性・無酸素性いずれについても正の影響を与える可能性が示唆された。

持久的トレーニングにより，骨格筋の脂肪酸酸化酵素活性が上昇することが良く知られている．しかしながら，高強度運動トレーニングが骨格筋の脂肪酸酸化酵素活性に及ぼす影響はこれまでほとんど明らかとされていない．そこで，本研究では，短時間のうちに行われる高強度・間欠的水泳運動トレーニングが骨格筋脂肪酸酸化酵素活性に及ぼす影響について，持久的トレーニングによる効果と比較検討した．4～5週齢のSD系雄ラットを1)高強度・間欠的トレーニング（HIT）群，2)持久的トレーニング（LIT）群，3)コントロール群（CON）の3群に無作為に分けた．HIT群には，体重の14～16％に相当する錘を装着させながら，20秒間の水泳運動を10秒間の休憩を挟みながら14セット行わせた．LIT群には，無負荷で3時間の水泳運動を45分間の休憩を挟み2セット行わせた．トレーニングは1日1回，10日間行わせた．最終トレーニングの翌日に，麻酔下において，心臓および内臓脂肪を摘出し，その重量を測定した．また，前肢骨格筋Tricepsを摘出し，骨格筋の脂肪酸β酸化において重要な役割を果たしていると考えられている 3-β-hydroxyacyl-CoA dehydrogenase（HAD）活性の測定に用いた．その結果，HIT群の心臓重量は，LITおよびCON群に比べて有意に高い値を示した．内臓脂肪量は，LIT群において，CON群に比べて有意に低い値を示した．前肢骨格筋TricepsにおけるHAD活性は，LITおよびHIT群で，CON群と比較して有意に高い値を示した．LIT群とHIT群のHAD活性には有意な差は認められなかった．以上の結果から，総運動時間が6時間の持久的トレーニングと同程度に，高強度・間欠的トレーニング（総運動時間：280秒）でも骨格筋の脂肪酸酸化酵素活性が上昇することが明らかとなった．