Abstract

Background

Although the negative relationship between cardiorespiratory fitness (CRF) or muscular fitness and diabetes mellitus were respectively observed in many previous studies, there is still a lack of studies that include CRF and muscular fitness simultaneously. Therefore, this study aimed to investigate the relationship between the combination of CRF and muscular fitness and diabetes through a cross-sectional study. 

Methods

This study was part of WASEDA'S Health Study, a cohort study launched in 2014. We used a part of the baseline data collected for this study. Maximal exercise test using a cycle ergometer and leg extension power (LEP) test were respectively used to evaluate CRF and muscular fitness. Since LEP is affected by body weight, relative LEP (rLEP) which is LEP per body weight, was used as an index of muscular fitness. 796 men (56.5 ± 10.4 years old) who completed a medical examination and fitness tests, were divided into two groups based on CRF and rLEP, respectively. The prevalence of diabetes was collected based on a self-reported questionnaire or blood test. Odds ratios and 95% confidence intervals (CIs) for the prevalence of diabetes were obtained using logistic regression models while adjusting for age, body mass index, exercise habits, family history of diabetes, smoking habits, and drinking habits.

Results

55 (7%) participants had diabetes. Compared to participants with lower CRF or rLEP, the odds ratio (95% CIs) of diabetes in those with higher CRF or rLEP was 0.46 (0.21–0.98) or 0.34 (0.16–0.74), respectively. Furthermore, using the lower CRF and lower rLEP group as the reference, the odds ratio (95% CIs) for the lower CRF and higher rLEP group was 0.32 (0.12–0.88), and higher CRF and higher rLEP group was 0.21 (0.07–0.63), after adjusting for potential confounding factors.

Conclusions

CRF and rLEP have independent and joint inverse associations with diabetes prevalence. In addition, participants with high CRF and high rLEP had a lower prevalence of diabetes compared to those with only high CRF or only high rLEP.

Abstract

Few studies have examined the association between coffee consumption and muscle mass; their results are conflicting. Therefore, we examined the association between coffee consumption and low muscle mass prevalence. We also performed an exploratory investigation of the potential effect modification by demographic, health status-related, and physical activity-related covariates. This cross-sectional study included 2085 adults aged 40–87 years. The frequency of coffee consumption was assessed using a self-administered questionnaire. Muscle mass was assessed as appendicular skeletal muscle mass/height² using a multifrequency bioelectrical impedance analyser. We defined low muscle mass using cut-offs recommended by the Asian Working Group for Sarcopenia. Multivariable-adjusted odds ratios for low muscle mass prevalence were estimated using a logistic regression model. The prevalence of low muscle mass was 5.4% (n = 113). Compared with the lowest coffee consumption group (<1 cup/week), the multivariable-adjusted odds ratios (95% confidence intervals) of low muscle mass prevalence were 0.62 (0.30, 1.29) for 1–3 cups/week, 0.53 (0.29, 0.96) for 4–6 cups/week or 1 cup/day, and 0.28 (0.15, 0.53) for ≥2 cups/day (P for trend <0.001). There were no significant interactions among the various covariates after Bonferroni correction. In conclusion, coffee consumption may be inversely associated with low muscle mass prevalence.

Background

Glucose and lipid tolerance reportedly exhibit diurnal variations, being lower in the evening than in the morning. Therefore, the effects of exercise on glucose and blood lipid levels at different times of the day may differ. This study aimed to investigate the effects of short-term endurance exercise intervention in the morning versus late afternoon on 24-h blood glucose variability and blood lipid levels.

Methods

Twelve healthy young men participated in a randomized crossover trial. The participants were assigned to morning (09:00–11:00) or late afternoon (16:00–18:00) endurance exercise for a week, consisting of supervised exercise sessions on Mondays, Wednesdays, and Fridays. In the morning and evening trials, the participants walked for 60 min on a treadmill at approximately 60% of maximal oxygen uptake (VO_2max). Following a 2-week wash-out period, the participants performed the exercise training regimen at another time point. Continuous glucose monitoring was used to evaluate blood glucose fluctuations during each 24-h trial period. Blood samples were collected before and after each intervention to examine blood lipid and hormonal responses.

Results

Examination of the area under the curve (AUC) of the glucose level changes for 24 h after the late afternoon versus morning exercise intervention revealed significantly lower values for the former versus the latter (P < 0.01). The AUC of glucose level changes after each meal was also lower after the late afternoon versus morning intervention, and significantly lower values were observed in the late afternoon versus morning trial for breakfast and dinner (P < 0.05, P < 0.01). In addition, a significant decrease in triglycerides (TG) and TG/high-density lipoprotein cholesterol (HDL-C) was noted after versus before the late afternoon intervention (P < 0.05).

Conclusions

These results suggest that late afternoon endurance exercise is more effective than morning endurance exercise at improving 24-h glucose and triglyceride levels.

Although many studies have reported that a posteriori dietary pattern is associated with metabolic health, there is little evidence of an association between dietary patterns and different metabolic phenotypes. The present study aimed to examine the association between major dietary patterns and different metabolic phenotypes (metabolically healthy non-obese [MHNO], metabolically unhealthy non-obese [MUNO], metabolically healthy obese [MHO], and metabolically unhealthy obese [MUO]) in middle-aged and elderly Japanese adults. This cross-sectional study enrolled 2,170 Japanese adults aged ≥40 years. The four different metabolic phenotypes were determined based on the presence of obesity, abdominal obesity, hypertension, hyperglycemia, and dyslipidemia. The major dietary patterns were determined using principal component analysis based on energy-adjusted food intake. Two dietary patterns were identified: the healthy dietary pattern, which was characterized by a high intake of vegetables, fruits, potatoes, soy products, mushrooms, seaweeds, and fish; and the alcohol dietary pattern, which was characterized by a high intake of alcoholic beverages, liver, chicken, and fish. The healthy dietary pattern was associated with the MHNO and MHO phenotypes (MUNO and MUO as reference groups, respectively), and the multivariate-adjusted odds ratios (ORs) (95% confidence intervals [CIs]) in the highest quartile of healthy dietary pattern score with the lowest quartile as the reference category were 2.10 (1.40-3.15) and 1.86 (1.06-3.25), respectively. Conversely, the alcohol dietary pattern was inversely associated with the MHNO and MHO phenotypes, while the multivariate-adjusted ORs (95% CIs) in the highest quartile of the alcohol dietary pattern score with the lowest quartile as the reference category were 0.63 (0.42-0.94) and 0.45 (0.26-0.76), respectively. There were no significant interactions between sex and healthy/alcohol dietary patterns in the prevalence of the MHNO and MHO phenotypes. In conclusion, the present study's findings suggest that major dietary patterns are associated with different metabolic phenotypes in middle-aged and elderly Japanese adults. These findings provide useful evidence for maintaining metabolic health through diet regardless of obesity status.

PURPOSE: The age-associated increase in arterial wall viscosity (AWV) is attenuated by high cardiorespiratory fitness level. However, AWV in endurance-trained athletes have not been determined. We designed a cross sectional study to compare central AWV and compliance between endurance-trained young athletes and age-matched control men. METHODS: Twenty-one endurance-trained men (age 20.7 ± 0.3 years) and 20 age-matched healthy control men (age 21.6 ± 0.4 years) were studied. The common carotid artery was measured noninvasively by tonometry and automatic tracking of B-mode images to obtain instantaneous pressure and diameter hysteresis loops, and we calculated the dynamic carotid arterial compliance, static (effective and isobaric) compliance, and viscosity index. RESULTS: The AWV index in the endurance-trained men was larger than the control peers (2285 ± 181 vs. 1429 ± 124 mmHg·s/mm: P < 0.001). In addition, dynamic and static compliance were not statistically different between both groups. CONCLUSION: The present study indicated that the central AWV in endurance-trained athletes was greater than age-matched healthy control men. We believe that the AWV, as well as arterial compliance, is an important element for assessing vascular adaptation to endurance training.

The association between a dietary pattern characterised by high alcohol intake and dyslipidaemia has not been fully investigated. Therefore, the present study aimed to investigate the association between alcohol dietary patterns and the prevalence of dyslipidaemia and its components. This cross-sectional study enrolled 2,171 men and women aged ≥40 years who were alumni of a Japanese university. To identify dietary patterns, a principal component analysis was performed based on the energy-adjusted food intake estimated by a brief-type self-administered diet history questionnaire. Three dietary patterns were identified, the second of which was named the alcohol dietary pattern and was characterised by a high intake of alcoholic beverages, liver, chicken, and fish. This alcohol dietary pattern was associated with reduced low-density lipoprotein cholesterol (LDL-C) levels. The fully adjusted odds ratios (95% confidence intervals) of high LDL-C for the lowest through highest quartile of alcohol dietary pattern score were 1.00 (reference), 0.83 (0.64-1.08), 0.84 (0.64-1.10), and 0.68 (0.49- 0.94), respectively. Subgroup analysis showed that the alcohol dietary pattern was inversely associated with the prevalence of dyslipidaemia in women, whereas it was positively associated with high triglyceride levels in men. In conclusion, the alcohol dietary pattern, characterised by a high intake of alcoholic beverages, liver, chicken, and fish, was associated with the prevalence of dyslipidaemia and its components. This finding provides useful information for the prevention and treatment of dyslipidaemia by modifying the diet.

Purpose We aimed to investigate the hypothesis that type I collagen plays a role in increasing bone mineral density (BMD) and muscle stiffness, leading to low and high risks of fatigue fracture and muscle injury, respectively, in athletes. As a potential mechanism, we focused on the effect of the type I collagen alpha 1 chain gene (COL1A1) variant associated with transcriptional activity on bone and skeletal muscle properties. Methods The association between COL1A1 rs1107946 and fatigue fracture/muscle injury was evaluated in Japanese athletes. Effects of the polymorphism on tissue properties (BMD and muscle stiffness) and type I collagen α1/α2 chain ratios in muscles were examined in Japanese nonathletes. Results The C-allele carrier frequency was greater in female athletes with fatigue fracture than in those without (odds ratio = 2.44, 95% confidence interval [CI] = 1.17-5.77) and lower in female athletes with muscle injury than in those without (odds ratio = 0.46, 95% CI = 0.24-0.91). Prospective validation analysis confirmed that in female athletes, muscle injury was less frequent in C-allele carriers than in AA genotype carriers (multivariable-adjusted hazard ratio = 0.27, 95% CI = 0.08-0.96). Among female nonathletes, the C-allele of rs1107946 was associated with lower BMD and lower muscle stiffness. Muscle biopsy revealed that C-allele carriers tended to have a larger type I collagen α1/α2 chain ratio than AA genotype carriers (2.24 vs 2.05, P = 0.056), suggesting a higher proportion of type I collagen α1 homotrimers. Conclusion The COL1A1 rs1107946 polymorphism exerts antagonistic effects on fatigue fracture and muscle injury among female athletes by altering the properties of these tissues, potentially owing to increased levels of type I collagen α1 chain homotrimers.

Previous studies have not investigated the determinants of resting oxidative stress, including physical fitness, as it relates to redox regulation. The present study therefore was aimed at identifying lifestyle and biological factors that determine resting oxidative stress, including objectively measured physical fitness. In 873 middle-aged and elderly men and women, age and anthropometric parameters, lifestyle-related parameters, medication and supplementation status, physical fitness, biochemical parameters, and nutritional intake status, as well as three plasma oxidative stress markers: protein carbonyl (PC), F2-isoprostane (F2-IsoP), and thiobarbituric acid reactive substances (TBARS), were surveyed and measured. The determinants of PC, F2-IsoP, and TBARS in all participants were investigated using stepwise multiple regression analysis. In PC, age (β = -0.11, P = 0.002), leg extension power (β = -0.12, P = 0.008), BMI (β = 0.12, P = 0.004), and HDL-C (β = 0.08, P = 0.040) were included in the regression model (adjusted R 2 = 0.018). In the F2-IsoP, smoking status (β = 0.07, P = 0.060), BMI (β = 0.07, P = 0.054), and HbA1c (β = -0.06, P = 0.089) were included in the regression model (adjusted R 2 = 0.006). In TBARS, glucose (β = 0.18, P < 0.001), CRF (β = 0.16, P < 0.001), age (β = 0.15, P < 0.001), TG (β = 0.11, P = 0.001), antioxidant supplementation (β = 0.10, P = 0.002), and HbA1c (β = -0.13, P = 0.004) were included in the regression model (adjusted R 2 = 0.071). In conclusion, the present study showed that age, anthropometric index, lifestyle-related parameters, medication and supplementation status, objectively measured physical fitness, biochemical parameters, and nutritional intake status explain less than 10% of oxidative stress at rest.

The relationships between cardiorespiratory fitness (CRF) measurements not confounded by adiposity and the prevalence of pre-diabetes mellitus (pre-DM) and diabetes mellitus (DM) are not well known. Thus, we aimed to investigate the associations of visceral fat (VF) and CRF with the prevalence of pre-DM/DM among Japanese adults. The study included 970 individuals (327 women and 643 men) who were 40-87 years old and had complete health examinations, abdominal fat area, and fitness data from WASEDA'S Health Study during 2015-2018. The VF area was measured using magnetic resonance imaging. CRF was measured using a cycle ergometer and was defined as VO2peak divided by fat free mass. The pre-DM/DM was identified based on the questionnaire and fasting blood tests. The odds ratios (ORs) and 95% confidence intervals (CIs) for prevalence of pre-DM/DM were calculated. Seventy-three participants had pre-DM and 48 participants had DM. Compared to the low VF group, the high VF group had a higher prevalence of pre-DM/DM (OR: 1.87, 95% CI: 1.18-2.96), although no significant relationship was observed between CRF and pre-DM/DM prevalence (P for trend = 0.239). The sub-group analyses also revealed no significant relationship between CRF and pre-DM/DM prevalence in the low VF group (P for trend = 0.979), although CRF values were inversely related to the prevalence of pre-DM/DM in the high VF group (P for trend = 0.024). Although CRF was not independently related to the prevalence of pre-DM/DM after adjusting for adiposity, higher VF values were related to a higher prevalence of pre-DM/DM. In addition, CRF levels were inversely associated with the prevalence of pre-DM/DM only among high VF individuals.

Background and objectives: It has been well established that the resting energy expenditure (REE) for the whole body is the sum of the REE for each organ-tissue in young and middle-aged healthy adults. Based on these previous studies, although it is speculated that sleeping energy expenditure (SEE, which has small inter-individual variability) changes with a commensurate gain or reduction in the resting metabolic rate of each organ-tissue, it is unclear whether a change in organ-tissue masses is directly attributed to the fluctuation of SEE at present. This study aimed to assess the relationship between changes in organ-tissue mass and sleeping energy expenditure (SEE) following weight change in college Sumo wrestlers. This included blood analysis, which is related to energy expenditure. Materials and Methods: A total of 16 healthy male college Sumo wrestlers were recruited in this study. All measurements were obtained before and after weight change. Magnetic resonance imaging measurements were used to determine the volume of the skeletal muscle (SM), liver, and kidneys, and an indirect human calorimeter was used to determine SEE before and after weight change. Results: The change in body mass and SEE ranged between −8.7~9.5 kg, and −602~388 kcal/day. Moreover, changes in SM, liver, and kidneys ranged between −3.3~3.6 kg, −0.90~0.77 kg, and −0.12~0.07 kg. The change in SEE was not significantly correlated with the change in SM or liver mass, nor with blood analyses; however, a significant relationship between the change in kidney mass and SEE was observed. Conclusions: Based on our results, there is a possibility that the mass of the kidneys has an effect on the change in SEE following weight change in college Sumo wrestlers.

AIM: To re-evaluate the suitability of calf circumference as a surrogate marker of low muscle mass measured by both bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA). We also examined the effects of obesity and age on low muscle mass screening using calf circumference. METHODS: In total, 1239 adults participated in this cross-sectional study. We measured the maximum calf circumference in a standing position and appendicular skeletal muscle mass (ASM) using BIA and DXA. We defined low muscle mass based on the Asian Working Group for Sarcopenia 2019 consensus. RESULTS: Calf circumference was positively correlated with BIA-measured ASM/height2 (men: r = 0.81, women: r = 0.73) and DXA-measured ASM/height2 (men: r = 0.78, women: r = 0.76). In the subgroup analyses by obesity and age, calf circumference was also positively correlated with ASM/height2 . The optimal calf circumference cut-offs for low muscle mass screening measured by BIA and DXA were 35 cm (sensitivity 91%, specificity 84%) and 36 cm (sensitivity 82%, specificity 80%) for men, and 33 cm (sensitivity 82%, specificity 84%) and 34 cm (sensitivity 85%, specificity 72%) for women, respectively. CONCLUSIONS: Calf circumference is positively correlated with BIA- and DXA-measured muscle mass regardless of obesity and age and is a simple and accurate surrogate marker of muscle mass for diagnosing sarcopenia. Geriatr Gerontol Int 2020; 20: 943-950.

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. This study aimed to examine when and how physical activity (PA) influences gestational weight gain (GWG) and infant birthweight (BW) by considering the PA’s total volume, timing, intensity, and type, controlling for the influence of energy intake. A total of 1272 participants in different stages of pregnancy were recruited from hospital. The associations between PA and GWG or BW in the latter half of pregnancy were significant. Women with the highest PA volume in the third trimester had significantly lower risks of inadequate and excessive GWG by 69% (OR = 0.31, 95%CI: 0.10–0.91) and 67% (OR = 0.33, 95% CI: 0.12–0.91), respectively, compared to women in the lowest quartile. Women who achieved the recommended moderate intensity of PA during their second and third trimesters, independent of total volume of PA, had infants with significantly lower BWs compared to those who did not (β = −0.15, SE = 66.33, p = 0.04; β = −0.20, SE = 64.54, p = 0.01, respectively). Therefore, the effects of total volume and intensity of PA on GWG and BW were different. Interventions to prevent inappropriate GWG and macrosomia may need to set different priorities and timing regarding total volume or intensity of PA.

This study examined the relationship between a healthy Japanese dietary pattern and micronutrient intake adequacy based on the Dietary Reference Intakes for Japanese 2015 (DRIs-J 2015) in men and women. A cross-sectional study was conducted in 1418 men and 795 women aged 40-87 years, who participated in the Waseda Alumni's Sports, Exercise, Daily Activity, Sedentariness, and Health Study. Dietary patterns were derived from principal component analysis of the consumption of 52 food and beverage items, which were assessed by a validated brief-type self-administered diet history questionnaire. Micronutrient intakes were quantified using the dietary reference intakes score (DRIs-score) for 21 micronutrients (based on DRIs-J 2015). The healthy dietary pattern score was significantly and positively correlated with the intakes of all 21 micronutrients used for constructing the DRIs-score in men and in women (each, p < 0.001). In both sexes, the healthy dietary pattern scores were strongly and positively associated with DRIs-scores (in men: ρ = 0.806, p < 0.001; in women: ρ = 0.868, p < 0.001), and the DRIs-scores reached a plateau around the highest tertile of the healthy dietary pattern score. These results indicate that a healthy Japanese dietary pattern is associated with adequate micronutrient intakes based on the DRIs-J 2015 in both men and women.

© 2019 The Author(s). Background: Physical activity (PA) and dietary intake are important modifiable factors associated with health outcomes. However, Chinese pregnant women's PA and dietary intake are only vaguely understood. The aim of this study was to reveal the characteristics of PA and dietary intake of Chinese women in different trimesters as well as the associations between PA and dietary intake. Methods: This is a cross-sectional observational study. PA, dietary intake, and demographics of 1077 Chinese pregnant women were measured. The Chi-square test, Kruskal-Wallis test, multiple logistic regression, and multiple linear regression were used for data analysis. Results: About 57.1% of the participants met the international guideline for PA. Household activity and occupational activity contributed the most to the total PA, while sports/exercise contributed little. The mean energy intake of the participants was 2008 ± 748.0 kcal. Most participants had normal energy intake, but they obtained excessive energy from fat (mean = 41.7 ± 8.7%). PA was not found to be significantly associated with dietary intake. Further, the participants who were unemployed during pregnancy (OR = 0.72, 95% CI: 0.55-0.95; p < 0.05) or had no exercise habits before pregnancy (OR = 0.62, 95% CI: 0.47-0.80; p < 0.01) were less likely to meet the PA guideline. The participants in the third trimester (OR = 1.43, 95% CI: 1.03-1.99; p < 0.05) were more likely to meet the PA guideline compared to those in the first trimester. The older participants (> 30 years) showed higher dietary intake than the younger (< 25 years) participants (p < 0.01). Conclusions: The total PA of Chinese women during pregnancy mostly consists of household and occupational activities, but little sports/exercise. Starting exercise before pregnancy may help women achieve adequate PA during pregnancy. Moreover, these women consumed an excessive amount of fat and their diet intake varies by age.

BACKGROUND/OBJECTIVES: In this study, we ascertained the relationship between resting energy expenditure (REE) obtained using two procedures: indirect calorimetry and from organ-tissue mass, calculated employing magnetic resonance imaging (MRI), and adult metabolic rate constants, in prepubertal children. Differences between the measured and the calculated REEs were assessed according to age at puberty approaching stage. SUBJECTS/METHODS: We recruited 6-12 years old 110 healthy Japanese prepubertal children (40 girls and 70 boys). Organ-tissue masses for different organs (skeletal muscle, liver, kidneys, brain and adipose tissue) were determined using MRI and dual-energy X-ray absorptiometry. Heart and residual masses were calculated on the basis of each equation. REE was measured using the Douglas bag technique (measured REE). On the other hand, calculated REE was obtained by multiplying the sum of body compartments with the corresponding adult tissue respiration rate. RESULTS: The measured REE was significantly greater than the calculated REE in both, boys and girls, although a significant association was noticed between the two REEs in both the sexes. Besides, correlation between age and difference in the two REEs was found to be significant only in girls. CONCLUSIONS: The present study revealed that: (1) measured and calculated REEs differ by approximately 300 kcal/day in a relatively large sample of prepubertal children, and (2) the difference in organ-tissue mass between the measured and calculated REEs increased from approximately 200 to 400 kcal/day during the developmental process in girls but not in boys.

AIM: Watching sports at stadiums can have a favorable impact on health-related outcomes in older adults. We examined the effect of watching professional baseball at a ballpark on older adults' health-related outcomes. METHODS: A total fo 58 participants aged 65-85 years were randomized into a spectator group (n = 29) and waiting-list group (n = 29). During the 2-month intervention, there were 21 games. The spectator group watched games at the ballpark, and the waiting-list group maintained their daily routines. The health-related outcomes were executive and cognitive functions, health-related quality of life, depression symptoms, subjective happiness and physical activity. RESULTS: The median days watching baseball games in the spectator group was 6 days (interquartile range 4-10 days). Executive function using the reverse Stroop interference rate showed a non-significant trend of improvement in the spectator group compared with the waiting-list group (P = 0.063). The spectator group showed a significant reduction in depressive symptoms compared with the waiting-list group (P = 0.016). CONCLUSIONS: Regularly watching professional baseball at a ballpark reduced older adults' depression symptoms. Geriatr Gerontol Int 2019; 19: 717-722.

OBJECTIVE: The aim of this study was to investigate the associations between dietary patterns and abdominal obesity among middle-aged and elderly Japanese people, using both waist circumference (WC) and visceral fat (VF) as indices. METHODS: A cross-sectional study was conducted with 829 adults (534 men and 295 women), 40 to 79 y of age, who participated in the Waseda Alumni's Sports, Exercise, Daily Activity, Sedentariness and Health Study (WASEDA'S Health Study). Dietary patterns were derived from principal component analysis. VF was measured using magnetic resonance imaging. To examine the associations of each dietary pattern with WC and VF, we calculated multivariate-adjusted means and 95% confidence intervals (CIs) of WC and VF for the tertile of each dietary pattern score. RESULTS: Two main dietary patterns were identified: "healthy Japanese" and "seafood and alcohol." The healthy Japanese dietary pattern score was inversely associated with WC and VF in men only. WC measurements were 84.9 cm (95% CI, 83.7-86.1), 83.9 cm (95% CI, 82.7-85.1), and 82.4 cm (95% CI, 81.2-83.6); Ptrend = 0.006, and VF measurements were 94.0 cm2 (95% CI, 85.6-102.4), 89.4 cm2 (95% CI, 81.1-97.7), and 80.4 cm2 (95% CI, 72.5-88.4); Ptrend = 0.027 for the lowest through the highest tertile of healthy Japanese dietary pattern scores in men. The seafood and alcohol dietary pattern was not associated with WC and VF. CONCLUSION: The healthy Japanese dietary pattern was negatively associated with WC and VF in middle-aged and elderly Japanese men.

Sumo wrestlers are a group of athletes who have high levels of fat mass and fat-free mass (FFM), not often observed in most other forms of competitive sports (Kanehisa et al., 1997). Research on sumo wrestlers is going to provide a clue for weight gain with enhancing sports performance. On energy balance of sumo wrestlers, energy intake exceeds energy expenditure over a considerable period for gaining weight because sumo wrestlers who have greater body mass possess one of the most effective ways to win. In fact sumo wrestlers have body weights in excess of 100. kg, with fat mass in excess of 30. kg and FFM greater than 80. kg (Kondo et al., 1994). Additionally, percent fat of the upper league wrestlers (Sekitori) was kept at about 25%, and FFM and the force generation capability were larger in the upper league wrestlers than in the lower leagues wrestlers (Kanehisa et al., 1998). Sumo wrestlers, especially "Sekitori" wrestlers, can be considered as "athletes.".

The effects of Chios mastic gum (Pistacia lentiscus var. Chia) and exercise on physical characteristics, blood lipid markers, insulin resistance, and hepatic function were investigated in healthy, non-smoking Japanese men aged ≥ 40 years. Participants were allocated to control (C, 5 g/day placebo powder, n = 7), mastic (M, 5 g/day mastic powder, n = 7), or mastic plus physical activity groups (M + PA, 5 g/day mastic powder and 30-min exercise three times/week, n = 7), and measurements were taken at baseline, 3 and 6 months. Serum triglycerides were significantly reduced at 3 months in M and M + PA compared with C (P &amp
lt
 0.05). Serum insulin and homeostatic model assessment of insulin resistance values were significantly reduced at 3 and 6 months in M + PA, and at 6 months in M, compared with C (P &amp
lt
 0.05). These results indicate that Chios mastic gum intake for 6 months reduced serum triglyceride and insulin concentrations, and additional exercise enhanced the effect on insulin.

It is difficult to precisely and easily estimate the changes in skeletal muscle mass (SMM) following exercise training. We aimed to assess whether the change in lean soft tissue mass measured using dual-energy X-ray absorptiometry (DXA) reflects the change in SMM measured using magnetic resonance imaging (MRI) following exercise training in both the leg and trunk regions. Anthropometry, DXA, and MRI measurements of the trunk and leg regions were obtained in 10 male college sumo wrestlers before and after exercise training (mean duration between measurements: ~2 yr). Contiguous magnetic resonance images with 1-cm slice thickness and without gap were obtained from the first cervical vertebra to the ankle joints as reference data. Skeletal muscle volume was calculated from the summation of the digitized cross-sectional areas. The volume measurements were converted into mass by using an assumed skeletal muscle density (1.041 g/cm3). Trunk and leg areas, using DXA regional computer-generated lines, were adjusted to coincide with each discrete region by using MRI. Although the change in the DXA-measured lean soft tissue mass in the trunk region was significantly different from that of the MRI-measured SMM (Cohen's d = −1.3145, concordance correlation coefficient = 0.26, p &lt
0.01), the changes were similar in the leg region (Cohen's d = 0.07, concordance correlation coefficient = 0.87, p = 0.88). The exercise training-induced change in lean soft tissue mass significantly correlated with that in SMM, both in the leg (r = 0.88, p &lt
0.01) and trunk (r = 0.64, p &lt
0.05) regions. Bland–Altman analysis did not indicate a bias for the changes in leg lean soft tissue mass and SMM following exercise training. These results suggest that lean soft tissue mass measured using DXA is an effective index for assessing change in leg SMM following exercise training.

Background and Study Aim: Many wrestlers undergo extreme dieting, with rapid weight loss and fluid restriction, to achieve rule weight as measured before a match. Insight into the genetics of weight loss has been gained from studies of patients with lifestyle-related diseases, including obesity and diabetes, who show weight loss resistance in the face of therapeutic interventions such as diet and exercise. However, the effect of single nucleotide polymorphisms (SNPs) in obesity-related genes on the rapid weight loss that athletes experience in weight-class sports such as wrestling remains to be elucidated. The purpose of this study was the effect of SNPs in ADRB3, ADRB2, and UCP1 on rapid weight loss in female wrestlers. Material and Methods: Twenty-two female wrestlers who sought weight loss before a match participated in this study. We performed real-time polymerase chain reaction using a quenching probe to determine subject genotypes. Results: Thirteen subjects had the ADRB3 (Trp/Trp) wild-type genotype, whereas 9 had the ADRB3 (Trp/Arg) polymorphic genotype. Five subjects had the ADRB2 (Arg/Arg) genotype, and 17 had the ADRB2 (Arg/Gly) polymorphic genotype. Five subjects had the UCP1 (−3826A/A) genotype, and 17 had the UCP1 (−3829A/G) polymorphic genotype. No statistically significant associations were detected between genotypes of obesity-related genes with any of the weight loss indicators measured. Conclusions: SNPs in the obesity-related genes ADRB3, ADRB2, and UCP1 do not appear to affect weight loss in female wrestlers during rapid weight loss regimens prior to a match.

© 2018 the Authors. Background and Study Aim: Materials and Methods: Results: Conclusions: Many athletes will lose weight 5% or more within 7 days. Many reports have been published on the negative health effects of rapid weight loss (RWL) in wrestlers. This study aim was the effects of different periods of RWL on dehydration state and oxidative stress. Participants were nine male collegiate wrestlers who reduce their body mass by 5% within short period in randomized order using the same methods. They have experienced 1-day, 3-days and 7-days) weight loss separated by more than 4 weeks. All participants reduced 5% of their body mass in all trials. Following the weight loss, they tried to regain all of their lost weight with an ad libitum diet for 14 h. Body composition and biochemical variables were measured at baseline and immediately after weight loss and weight regain. There were no statistically significant differences in hematocrit, serum sodium, chloride, potassium, calcium, osmotic pressure, and antidiuretic hormone. For plasma aldosterone concentrations and plasma d-ROMs concentrations, two-way analysis of variance revealed the main effect of time (p<0.05). RWL (loss of 5% of body weight within 7 days) is surmised to have increased oxidative stress via dehydration and elevated levels of aldosterone. Although different weight loss periods did not yield any changes, RWL of 5% of body weight was suggested to increase oxidative stress. It is necessary to study the influence of weight loss cycling on athlete’s disease risk in the future.

We examined the relationship between frequency of watching baseball games and thephysical, social, and psychological characteristics among elderly people who participated in anintervention study titled effects of spectating professional baseball at the stadium on healthrelatedoutcomes in middle-aged and older adults. We used self-administered questionnaires andsurveys to determine physical, social, and psychological characteristics. During the study period, weprovided participants with free tickets to professional baseball games. We recommended that eachparticipant attend at least two games per month, but to avoid excessive attendance. Following thestudy period, we used questionnaires to determine the characteristics associated with attendance atprofessional baseball games. Whether or not a participant attended games frequently was used asthe objective variable, and other characteristics were used as explanatory variables in a stepwisemultiple regression or multiple logistic regression analysis, to determine which physical, social, andpsychological characteristics correlated with attendance frequency.There were 57 participants in this study, with a mean age of 74 years. The mean attendancefrequency was 3.3 times per month. Attendance frequency had a significant negative correlationwith the presence of an orthopedic disorder. There was a significant positive correlation with thefrequency of attendance at social outings. There was also a significant negative correlation withsubjective happiness and a positive correlation with physical quality of life. This study showed thatelderly participants who frequently attended professional baseball games did not have orthopedicdiseases, tended to go on frequent, regular outings, had a low level of subjective happiness, and had a high physical quality of life. Further study is needed to clarify the factors correlated with attendance at sporting events by the elderly. The information can be used to provide an environment conducive to attendance by the elderly at sporting events in stadiums.

Purpose
We hypothesized that body mass-to-waist ratio is strongly associated with the total-body skeletal muscle volume (SMV) in children. The purpose of the present study was to examine this hypothesis.
Methods
By using magnetic resonance imaging, total-body SMV (SMVMRI) was determined in 70 boys and 53 girls aged 6 to 12 years. Waist was measured at each of the level of umbilicus (Wumb) and the minimum circumference (Wmin), and the ratio of body mass to each of the two measured values was calculated (BM/Wumb and BM/Wmin, respectively). A single regression analysis was used to examine the relationships between SMVMRI and either BM/Wumb or BM/Wmin. On the basis of the obtained regression equations, SMVMRI was estimated and referred to as SMVBM/Wumb or SMVBM/Wmin.
Results
In both boys and girls, SMVMRI was highly correlated to BM/Wumb (r = 0.937 for boys and r = 0.939 for girls, P &lt; 0.0001) and BM/Wmin (r = 0.915 and 0.942, P &lt; 0.0001). R-2 and the standard error of estimate for SMVBM/Wumb were 0.878 and 706.2 cm(3), respectively, in boys and 0.882 and 825.3 cm(3), respectively, in girls, and those for SMVBM/Wmin were 0.837 and 814.0 cm(3), respectively, in boys and 0.888 and 804.1 cm(3), respectively, in girls. In both boys and girls, there were no significant differences between SMVMRI and either SMVBM/Wumb or SMVBM/Wmin, without systematic errors in Band-Altman plots. There was no significant effect of model on the absolute values of the residuals in both boys and girls.
Conclusion
The current results indicate that body mass-to-waist ratio can be a convenient outcome measure for assessing the total-body skeletal muscle volume in children.

This study examined the validity of segmental bioelectrical impedance (BI) analysis for predicting the fat-free masses (FFMs) of whole-body and body segments in children including overweight individuals. The FFM and impedance (Z) values of arms, trunk, legs, and whole body were determined using a dual-energy X-ray absorptiometry and segmental BI analyses, respectively, in 149 boys and girls aged 6 to 12 years, who were divided into model-development (n = 74), cross-validation (n = 35), and overweight (n = 40) groups. Simple regression analysis was applied to (length)(2)/Z (BI index) for each of the whole-body and 3 segments to develop the prediction equations of the measured FFM of the related body part. In the model-development group, the BI index of each of the 3 segments and whole body was significantly correlated to the measured FFM (R-2 = 0.867-0.932, standard error of estimation = 0.18-1.44 kg (5.9%-8.7%)). There was no significant difference between the measured and predicted FFM values without systematic error. The application of each equation derived in the model-development group to the crossvalidation and overweight groups did not produce significant differences between the measured and predicted FFM values and systematic errors, with an exception that the arm FFM in the overweight group was overestimated. Segmental bioelectrical impedance analysis is useful for predicting the FFM of each of whole-body and body segments in children including overweight individuals, although the application for estimating arm FFM in overweight individuals requires a certain modification.

BACKGROUND: Leukocyte cell-derived chemotaxin 2 (LECT2) is a hepatokine linking obesity to skeletal muscle insulin resistance. Although previous studies reported that obesity was associated with high levels of circulating LECT2 in human, the associations of detailed body fat distribution with LECT2 levels have not been examined. Furthermore, although animal study suggested that exercise decreased circulating LECT2 levels, it remains unknown whether physical fitness is associated with LECT2 levels in human. We therefore examined the relationship of plasma LECT2 levels with various adiposity indices and cardiorespiratory fitness (CRF) in middle-aged and elderly Japanese men. Furthermore, we examined the relationship of LECT2 levels with the presence of metabolic syndrome, hypertension, insulin resistance and dyslipidemia to determine the clinical significance of measuring circulating LECT2. MATERIALS AND METHODS: This was a cross-sectional study of 143 Japanese men (age: 30-79 years). Participants' plasma LECT2 levels were measured by an enzyme-linked immunosorbent assay. To assess their abdominal fat distributions, visceral fat area (VFA) and subcutaneous fat area (SFA) were measured using magnetic resonance imaging. CRF was assessed by measuring peak oxygen uptake ([Formula: see text]). RESULTS: All adiposity indices measured in this study were positively correlated with plasma LECT2 levels, while [Formula: see text] was negatively correlated with LECT2 levels after adjustment for age. The correlations, except for VFA were no longer significant with further adjustment for VFA. Stepwise multiple linear regression analysis revealed that VFA was the strongest predictor of plasma LECT2 levels. Plasma LECT2 levels differed based on the presence of metabolic syndrome and dyslipidemia, but not hypertension and insulin resistance. Logistic regression analyses revealed that plasma LECT2 levels were significantly associated with dyslipidemia independently of VFA; VFA was not significantly associated with dyslipidemia after adjustment for LECT2. CONCLUSION: VFA was the strongest predictor of plasma LECT2 that is a potential biomarker linking visceral obesity to dyslipidemia.

The aim of this study was to investigate the effects of 8 weeks of training on O2 dynamics in university rugby players. University rugby players (n = 15) participated in 5 strength training sessions and 4 field-based training sessions per week for 8 weeks. Before and after 8-weeks’ training, the subjects performed ramp cycling exercise until exhaustion. Muscle O2 saturation (SmO2), relative changes from rest in deoxygenated hemoglobin concentration (∆Deoxy-Hb) and total hemoglobin concentration, cardiac output (CO), and pulmonary O2 uptake (VO2) were monitored continuously during exercise. Peak VO2 and CO were normalized by fat-free mass. Though peak VO2 tended to be increased after training, there were no significant changes in CO, nor any muscle O2 dynamic variables at peak exercise between before and after training. However, an increase in peak VO2 was significantly correlated with diminishment of deoxy-Hb and an increase in SmO2. Changes in CO caused by training were not related to improved peak VO2. The improvement of peak VO2 during 8 weeks of rugby training may have been caused by muscle O2 supply, rather than increased CO or muscle O2 extraction.

Objective: To determine the effects of watching a professional baseball game on the affect and subjective happiness of elders without a specific team to support. Method: Elderly Japanese (n = 16) were instructed to watch baseball games at a ballpark. They answered a questionnaire several weeks before (baseline) and, on the day of the game, before and after watching the game. Participants' affect and happiness were assessed using the General Affect Scale and Subjective Happiness Scale, respectively. Results: Calmness had a tendency to increase from baseline to before watching the game (p = .052). Furthermore, subjective happiness significantly increased after watching the game, compared with baseline (p = .017). Discussion: Visiting a ballpark to watch a professional baseball game increased elders' subjective happiness after they had finished watching it.

Objectives The objectives of the present study were to translate the English version of the Pregnancy Physical Activity Questionnaire into Chinese (PPAQ-C) and to determine its reliability and validity for use by pregnant Chinese women. Methods The study included 224 pregnant women during their first, second, or third trimesters of pregnancy who completed the PPAQ-C on their first visit and wore a uniaxial accelerometer (Lifecorder; Suzuken Co. Ltd) for 7 days. One week after the first visit, we collected the data from the uniaxial accelerometer records, and the women were asked to complete the PPAQ-C again. Results We used intraclass correlation coefficients to determine the reliability of the PPAQ-C. The intraclass correlation coefficients were 0.77 for total activity (light and above), 0.76 for sedentary activity, 0.75 for light activity, 0.59 for moderate activity, and 0.28 for vigorous activity. The intraclass correlation coefficients were 0.74 for "household and caregiving", 0.75 for "occupational" activities, and 0.34 for "sports/exercise". Validity between the PPAQ-C and accelerometer data was determined by Spearman correlation coefficients. Although there were no significant correlations for moderate activity (r = 0.19, P &gt; 0.05) or vigorous activity (r = 0.15, P &gt; 0.05), there were significant correlations for total activity [light and above; r = 0.35, P &lt; 0.01)] and for light activity (r = 0.33, P &lt; 0.01). Conclusions for Practice The PPAQ-C is reliable and moderately accurate for measuring physical activity in pregnant Chinese women.

To study the effects of different exercise intensity performed at different exercise times on lipid metabolism response during prolonged exercise. Nine young men performed endurance exercise at different exercise intensities (60% VO(2)max or Fatmax) in the morning (9 am to 10 am) or evening (5 pm to 6 pm); blood samples were collected before exercise and immediately and one and two hours after exercise completion. Expired gas was analyzed from the start of exercise until two hours after exercise completion. There were no significant changes in catecholamine (adrenaline and noradrenaline) and free fatty acid levels between morning and evening trials for each endurance exercise intensity. However, the morning and evening trials both exhibited significantly higher lipid oxidation at Fatmax than that at 60% VO(2)max. These results suggest that exercise at Fatmax offers greater lipid oxidation than that at 60% VO(2)max, regardless of exercise timing.

Short-term intake of a high-fat diet aggravates postprandial glucose metabolism; however, the dose-response relationship has not been investigated. We hypothesized that short-term intake of a eucaloric low-carbohydrate/high-fat diet (LCHF) would aggravate postprandial glucose metabolism and circulating adhesion molecules in healthy males. Seven healthy young males (mean +/- SE; age: 26 +/- 1 years) consumed either a eucaloric control diet (C, approximately 25% fats), a eucaloric intermediate-carbohydrate/ intermediate-fat diet (ICIF, approximately 50% fats), or an LCHF (approximately 70% fats) for 3 days. An oral meal tolerance test (MTT) was performed after the 3-day dietary intervention. The concentrations of plasma glucose, insulin, glucagon-like peptide-1 (GLP-1), intercellular adhesion molecule-1, and vascular cell adhesion molecule-1 (VCAM-1) were determined at rest and during MTT. The incremental area under the curve (iAUC) of plasma glucose concentration during MTT was significantly higher in LCHF than in C (P = 0.009). The first-phase insulin secretion indexes were significantly lower in LCHF than in C (P = 0.04). Moreover, the iAUC of GLP-1 and VCAM-1 concentrations was significantly higher in LCHF than in C (P = 0.014 and P = 0.04, respectively). The metabolites from ICIF and C were not significantly different. In conclusion, short-term intake of eucaloric diet containing a high percentage of fats in healthy males excessively increased postprandial glucose and VCAM-1 concentrations and attenuated first-phase insulin release.

The present study aimed to examine diurnal variation of the diving bradycardia responses on the same day.
Eighteen young men (age 26 +/- A 2 years; height 174.2 +/- A 6.0 cm; body mass 70.2 +/- A 8.1 kg; body fat 18.0 +/- A 3.8 %; mean +/- A standard deviation) participated in this study. Oral temperature, heart rate variability (HRV) from 5-min of electrocardiogram data, and diving bradycardia responses were measured at 0900, 1300, and 1700 hours daily. All participants performed diving reflex tests twice in the sitting position with the face immersed in cold water (1.9-3.1 A degrees C) and apnea at midinspiration for a minimum of 30 s and as long as possible, in consecutive order.
Oral temperature was found to be less in the morning (0900) than in the afternoon (1300) and evening (1700). In the frequency domain parameters of heart rate variability, the natural logarithms of high-frequency power were higher in the morning than in the evening. All participants showed bradycardia response to the two diving reflex tests. The peak values of R-R interval during the diving reflex test both for as long as possible and 30 s were longer in the morning than in the afternoon and evening.
Our results indicated that the maximal bradycardia during the diving reflex test exhibits a diurnal variation, with peak levels at morning and gradual decrease towards the evening. The HRV indexes show the same variation.

Muscle O-2 dynamics during ramp cycling exercise were compared between aerobic capacity-matched elderly men (n = 8, age 65 +/- 2 years) and women (n = 8, age 66 +/- 3 years). Muscle O-2 saturation (SmO2) and relative change in deoxygenated (Delta deoxy-Hb) and total hemoglobin concentration (Delta total-Hb) were monitored continuously during exercise in the vastus lateralis (VL) and gastrocnemius medialis (GM) by near infrared spatial resolved spectroscopy. SmO2 was significantly higher during exercise in women than in men in VL, but not in GM. In VL, Delta deoxy-Hb and Delta total-Hb were significantly higher in men than in women, especially during high intensity exercise. However, no significant difference was observed in Delta deoxy-Hb or Delta total-Hb in GM. Sex-related differences in muscle deoxygenation response may be heterogeneous among leg muscles in elderly subjects.

Very few effective field methods are available for accurate, non-invasive estimation of skeletal muscle volume (SMV) and mass in children. We aimed to develop regression-based prediction equations for SMV, using ultrasonography, in Japanese prepubertal children, and to assess the validity of these equations. In total, 145 healthy Japanese prepubertal children aged 6-12 years were randomly divided into two groups: the model development group (sixty boys, thirty-seven girls) and the validation group (twenty-nine boys, nineteen girls). Reference data in the form of contiguous MRI with 1-cm slice thickness were obtained from the first cervical vertebra to the ankle joints. The SMV was calculated by the summation of digitised cross-sectional areas. Muscle thickness was measured using B-mode ultrasonography at nine sites in different regions. In the model development group, strong, statistically significant correlations were observed between the site-matched SMV (total, arms, trunk, thigh and lower legs) measured by MRI and the muscle thickness x height measures obtained by ultrasonography, for both boys and girls. When these SMV prediction equations were applied to the validation groups, the measured total and regional SMV were also very similar to the values predicted for boys and girls, respectively. With the exception of the trunk region in girls, the Bland-Altman analysis for the validation group did not indicate any bias for either boys or girls. These results suggest that ultrasonography-derived prediction equations for boys and girls are useful for the estimation of total and regional SMV.

Purpose
To compare the effects of endurance exercise performed in the morning and evening on inflammatory cytokine responses in young men.
Methods
Fourteen healthy male participants aged 24.3 +/- 0.8 years (mean +/- standard error) performed endurance exercise in the morning (0900-1000 h) on one day and then in the evening (1700-1800 h) on another day with an interval of at least 1 week between each trial. In both the morning and evening trials, the participants walked for 60 minutes at approximately 60% of the maximal oxygen uptake ((V) over dotO(2max)) on a treadmill. Blood samples were collected to determine hormones and inflammatory cytokines at pre-exercise, immediately post exercise, and 2 h post exercise.
Results
Plasma interleukin (IL)-6 and adrenaline concentrations were significantly higher immediately after exercise in the evening trial than in the morning trial (P &lt; 0.01, both). Serum free fatty acids concentrations were significantly higher in the evening trial than in the morning trial at 2 h after exercise (P &lt; 0.05). Furthermore, a significant correlation was observed between the levels of IL-6 immediately post-exercise and free fatty acids 2 h post-exercise in the evening (r = 0.68, P &lt; 0.01).
Conclusions
These findings suggest that the effect of acute endurance exercise in the evening enhances the plasma IL-6 and adrenaline concentrations compared to that in the morning. In addition, IL-6 was involved in increasing free fatty acids, suggesting that the evening is more effective for exercise-induced lipolysis compared with the morning.

Background: Sedentary behavior, which includes sitting and TV viewing, has been identified as an independent risk factor for type 2 diabetes and cardiovascular disease. Breaking sedentary behavior improves metabolic health such as postprandial glycaemia and insulinemia. However, the mechanisms underlying this effect are unclear. Objectives: Here, we examined whether breaking sitting by standing and acute exercise reduces postprandial oxidative stress. Patient and Methods: Fifteen participants performed 3 trials (sitting, standing, and exercise), each lasting 2 days, in a randomised order. On day one of sitting trial, participants sat in a chair. For the standing trial, the participants stood 6 times, for a 45-minute period each time. For the exercise trial, the participants walked or ran at approximately 60% of age-predicted maximum heart rate for 30 minutes. On day two of each trial, participants rested and consumed the standardised breakfast and lunch. Blood samples were collected in the morning and afternoon on day one, and fasting and at 2, 4, and 6 hours postprandially on day two. Results: The concentrations of serum derivatives of reactive oxygen metabolites (d-ROMs) measured at 4 hours (P = 0.064) and 6 hours (P = 0.071) tended to be higher than that in the fasting state in the sitting trial, but not standing and exercise trial (two-factor analysis of variance (ANOVA), trial × time interaction, P = 0.006). Conclusions: Our results indicate the importance of reducing sitting time for improving postprandial oxidative stress status.

Aim: This study aimed to examine whether cardiorespiratory fitness (CRF) is associated with arterial stiffening, evaluated using the cardio-ankle vascular index (CAVI), independent of visceral fat (VF) in middle-aged and elderly Japanese men. We also examined whether the relationship between CRF and the CAVI is modified by age and/or hypertension.
Methods: The CAVI was determined in 157 Japanese men (age range, 30-79 years), including 96 hypertensive subjects (61.1%). CRF was assessed by measuring the peak oxygen uptake (VO(2)peak). The subjects were divided into low- and high-CRF groups, and the VF area was assessed using magnetic resonance imaging.
Results: The VO(2)peak correlated with the CAVI following adjustment for age and body mass index in the middle-aged and elderly groups (all the subjects: r = -0.285, p&lt;0.001; middle-aged: r = -0.240, p = 0.040; elderly: r = -0.225, p = 0.049). VF also correlated with the CAVI (r = 0.230, p = 0.004). A multiple linear regression analysis revealed that age (beta = 0.406, p&lt;0.001) and the VO(2)peak (beta = -0.186, p = 0.015) were associated with the CAVI independently of VF and the mean blood pressure. Two-way ANCOVA adjusted for age demonstrated that the hypertensive individuals had higher CAVI values than the normotensive individuals in the low-CRF group, whereas no significant differences in the CAVI were observed in the high-CRF group (p for interaction &lt;0.05).
Conclusions: In the present study, CRF was found to be associated with the CAVI, independent of age and VF, in hypertensive middle-aged and elderly Japanese men.

Exercise is a stressor, and living organisms respond differently to various exercise patterns. This chapter describes one such biological response, the response patterns of the autonomic nervous and endocrine systems with a focus on stress hormones. Exercise-related accidents, especially in relation to the abnormal secretion of stress hormones that leads to chronic fatigue and sleep deprivation and which may cause sudden death, are also discussed.

Context: Fibroblast growth factor-21 (FGF21) is an important metabolic regulator suggested to improve glucose metabolism and prevent dyslipidemia. An FGF21-resistant state that increases circulating FGF21 has been reported in obese patients. Although regular exercise prevents metabolic disease, the relationship of the fitness level to serum FGF21 level and body fat distribution in humans remains poorly understood.
Objective: The objective of the study was to determine the relationship among the serum FGF21 concentration, cardiorespiratory fitness (CRF) level, and visceral fat area (VFA).
Design: Serum FGF21 was measured by an ELISA in 166 middle-aged and elderly Japanese men (aged 30-79 y) and 25 untrained and 21 endurance-trained young men (aged 19-29 y). CRF was assessed by measuring the peak oxygen uptake (VO(2)peak) and VFA by magnetic resonance imaging.
Results: In the middle-aged and elderly subjects, the serum FGF21 level correlated with the VO(2)peak (r = -0.355, P &lt; .001) and VFA (r = 0.487, P &lt; .001). Stepwise multiple regression analysis showed VFA to be most strongly associated with the serum FGF21 level (beta = .360, P &lt; .001), and VO(2)peak was also an independent predictor of the serum FGF21 level (beta = -.174, P = .019). Furthermore, the proportion of subjects with an FGF21 level below the limit of detection was significantly higher among the endurance-trained than among the untrained young men (71.4% vs 24.0%, P = .001), and the VO2 peak and VFA were independently associated with an undetectable FGF21 level (P &lt; .05).
Conclusions: CRF and VFA are key determinants of the circulating FGF21 concentration.

Genome-wide association studies identified single nucleotide polymorphisms (SNPs) associated with body mass index (BMI) in middle-aged populations; however, it is unclear whether these SNPs are associated with body fatness in elderly people. We examined the association between genetic risk score (GRS) from BMI-associated SNPs and body fatness in elderly Japanese men. We also examined the contribution of GRS, dietary macronutrient intake, and physical activity to body fatness by different age groups. GRS was calculated from 10 BMI-associated SNPs in 84 middle-aged (30-64 years) and 97 elderly (65-79 years) Japanese men; subjects were divided into low, middle, and high GRS groups. Dietary macronutrient intake was assessed using a questionnaire, and physical activity was evaluated using both a questionnaire and an accelerometer. The middle-aged individuals with a high GRS had greater BMI; waist circumference; and total abdominal fat, visceral fat, and subcutaneous fat areas than the middle-aged individuals with low GRS, whereas the indicators were not different between the GRS groups in elderly individuals. Multiple linear regression analysis showed that GRS was the strongest predictor of BMI, total abdominal fat, and visceral fat in the middle-aged group, whereas fat, alcohol, and protein intakes or vigorous-intensity physical activity were more strongly associated with these indicators than was GRS in the elderly group. These results suggest that GRS from BMI-associated SNPs is not predictive of body fatness in elderly Japanese men. The stronger contribution of dietary macronutrient intake and physical activity to body fatness may attenuate the genetic predisposition in elderly men.

High cardiorespiratory fitness (CRF) is associated with a reduced risk of Type 2 diabetes mellitus (T2DM) and improved beta-cell function; genetic factors also determine these risks. This cross-sectional study investigated whether CRF modifies the association of polygenic risk of T2DM with glucose metabolism in nondiabetic Japanese men. Fasting plasma glucose, insulin, and glycated hemoglobin (HbA1c) levels were measured in 174 Japanese men (age: 20-79 yr). beta-Cell function and insulin resistance were evaluated by calculating HOMA-beta and HOMA-IR, respectively. CRF was assessed by measuring maximal oxygen uptake ((V) over dot(O2max)). Subjects were divided into the low and high CRF groups within each age group according to the median (V) over dot(O2max). Eleven single nucleotide polymorphisms (SNPs) associated with T2DM were analyzed and used to calculate genetic risk score (GRS); subjects were divided into the low, middle, and high GRS groups. The high GRS group had higher HbA1c levels than the low GRS group in both the low and high CRF groups (P &lt; 0.05). Furthermore, the individuals with a high GRS had a lower HOMA-beta than those with a low GRS regardless of CRF (P &lt; 0.05). In multiple linear regression analysis, although GRS was a significant predictor of HbA1c (beta = 0.153, P = 0.025), (V) over dot(O2max) was also associated with HbA1c (beta = -0.240, P = 0.041) independent of GRS. These results suggest that CRF is associated with HbA1c levels independent of GRS derived from T2DM-related SNPs; however, it does not modify the association of GRS with increased HbA1c or impaired beta-cell function.

Objective. This cross-sectional study analyzed the association of serum irisin concentrations with cardiorespiratory fitness levels and common single nucleotide polymorphisms (SNPs) in the FNDC5 gene and examined the relationships between cardiorespiratory fitness levels, common SNPs in FNDC5, and glucose metabolism.
Materials/Methods. Cardiorespiratory fitness was assessed by measuring peak oxygen uptake (VO(2)peak) and serum irisin levels by ELISA in 163 Japanese men (age, 21-79 years). Subjects were divided into low- and high-fitness groups within each age group according to the median VO(2)peak value. Common SNPs (rs3480 and rs16835198) of the FNDC5 gene were genotyped with the TaqMan assay. Glucose metabolism was evaluated by measuring HbA1c, fasting plasma glucose (FPG), insulin levels, and HOMA-IR.
Results. Serum irisin levels were negatively correlated with age (p &lt;0.001) and not associated with the VO(2)peak or HOMA-IR. In the low-fitness group, SNP analysis revealed that subjects with the rs3480 AG and GG genotypes had higher levels of insulin and HOMA-IR than those with the AA genotype (p &lt;0.01; no significant difference was observed in the high-fitness group). The GG genotypes of rs16835198 were associated with increased HbA1c and FPG in the low-fitness group only (p &lt;0.05). SNPs and both fitness groups were not associated with serum irisin levels.
Conclusions. In Japanese men, cardiorespiratory fitness levels and common SNPs in FNDC5 are not associated with circulating irisin levels, whereas high cardiorespiratory fitness abolishes the association between the rs3480 and rs16835198 SNPs and glucose metabolism independent of serum irisin levels. (C) 2014 Elsevier Inc. All rights reserved.

High cardiorespiratory fitness (CRF) is associated with a reduced risk for dyslipidemia; however, blood lipid levels are also affected by individual genetic variations. We performed a cross-sectional study to determine whether CRF modifies polygenic risk for dyslipidemia. Serum levels of triglycerides (TG), LDL cholesterol (LDL-C), and HDL cholesterol (HDL-C) were measured in 170 Japanese men (age 20-79 yr). CRF was assessed by measuring maximal oxygen uptake ((V) over dot O-2max), and subjects were divided into low-fitness and high-fitness groups according to the reference (V) over dot O-2max value for health promotion in Japan. We analyzed 19 single nucleotide polymorphisms (SNPs) associated with TG, LDL-C, or HDL-C levels. Based on these SNPs, we calculated three genetic risk scores (GRSs: TG-GRS, LDL-GRS, and HDL-GRS), and subjects were divided into low, middle, and high groups according to the tertile for each GRS. Serum TG levels of low-fitness individuals were higher in the high and middle TG-GRS groups than in the low TG-GRS group (P &lt; 0.01 and P &lt; 0.05, respectively), whereas no differences were detected in the TG levels of high-fitness individuals among the TG-GRS groups. In contrast, the high LDL-GRS group had higher LDL-C levels than did the low LDL-GRS group, and HDL-C levels were lower in the high HDL-GRS group than in the low HDL-GRS group regardless of the fitness level (P &lt; 0.05). These results suggest that high CRF attenuates polygenic risk for hypertriglyceridemia; however, high CRF may not modify the polygenic risk associated with high LDL-C and low HDL-C levels in Japanese men.

Maximal fat oxidation (MFO) rate and the exercise intensity that elicits MFO (FATmax-intensity) were designed to evaluate fat metabolism capacity and to provide individuals with a target exercise intensity during prolonged exercise. However, the previous methods of determining FATmax-intensity were time-consuming. The purpose of this study was to examine the validity of FATmax-intensity determined by short-time testing. Nine healthy young men performed ramp exercise, in a short-time test, until exhaustion and 5 constant-load exercises of 60min each at individual FATmax-intensity determined by ramp protocol (FATmax-intensity((R))), FATmax-intensity((R))+/- 5% of peak oxygen uptake (VO(2)peak) and FATmax-intensity((R))+/- 10%VO(2)peak. FATmax-intensity was determined among 5 trials at points of early exercise (10min) and prolonged exercise (60min) to evaluate the validity of FATmax-intensity((R)). Ten minutes after starting constant-load exercise, FATmax-intensity((R)) showed the highest fat oxidation among 5 trials, even though MFO by ramp protocol was overestimated. Therefore, it may be useful for evaluation of fat metabolism to include the measurement of the FATmax-intensity in a routine ramp test. However, because FATmax-intensity((R)) did not elicit the highest fat oxidation among 5 trials of 60min each after starting constant-load exercise, FATmax-intensity((R)) may not be effective for prolonged exercise training.

Muscle O-2 saturation (SmO2) and blood volume response in activating muscles during treadmill exercise were compared between prepubertal boys (n = 9, age: 9 +/- 1 years) and young men (n = 9, age: 22 +/- 2 years). SmO2 and blood volume responses were monitored continuously during the exercise at the gastrocnemius medialis muscle by near infrared spatial resolved spectroscopy. SmO2 was significantly decreased only at peak exercise in the boys, even though a significant decrease in SmO2 was observed at 60, 80, and 100 % of peak O-2 uptake in the men (p &lt; 0.05). No significant increase in blood volume was observed in the boys, while blood volume was significantly increased in the men with increased exercise intensity (p &lt; 0.05). These results suggest that both blood volume and deoxygenation response in activating muscle may be minor in prepubertal boys, compared to young men. The blunted deoxygenation response in prepubertal boys may be caused by undeveloped diffusive O-2 transport (i.e. mitochondrial respiration).

The purpose of this study was to investigate the effects of low-volume exercise training (90 min/wk) and vitamin E supplementation on oxidative stress markers in postmenopausal women. The participants were non-randomly assigned the following four groups: control (C, n=8), vitamin E (S, n=8), exercise (Ex, n=6), or vitamin E and exercise (S+Ex, n=7). The S and S+Ex groups were instructed to take vitamin E (alpha-tocopherol, 300 mg/d) capsules for 12 wk. The exercise program of Ex and S+Ex groups consisted of walking for a 30-60 min/session 2 d per week for 12 wk. The serum derivatives of reactive oxygen metabolites concentrations were significantly decreased in the Ex, and S+Ex groups after 12 wk compared with the baseline values (three-factor ANOVA, an interaction between exercise and time, p&lt;0.05). Conversely, serum biological antioxidant potential concentrations in the S and Ex groups were significantly higher at 12 wk than at the baseline, but not in the S+Ex group (three-factor ANOVA, an interaction between supplementation, exercise and time, p&lt;0.05). Plasma thioredoxin concentrations in the S, Ex, and S+Ex groups were significantly higher at 12 wk than at the baseline values (three-factor ANOVA, interactions between exercise and time, and between supplementation, exercise and time, p&lt;0.05). Our findings suggest that low-volume physical activity may improve resting oxidative stress status in postmenopausal women.

Objective. A single bout of exercise can improve acute postprandial glucose metabolism aggravated by short-term low-carbohydrate/high-fat diet (HFD). The purpose of this study was to investigate the effect of a single bout of aerobic exercise on short-term HFD-induced postprandial glucose and incretin metabolism during an oral glucose tolerance test (OGTT).
Materials/Methods. Eleven healthy young men (age [mean +/- SE] 27 +/- 1 years; body mass index, 22 +/- 1 kg/m(2)) performed three, 3-day interventions in randomized order: (1) a normal diet (ND: similar to 22% fat), (2) an HFD (similar to 69% fat) and (3) an HFD with a single bout of aerobic exercise (HFDEx). The exercise (50% peak oxygen consumption; similar to 200 kcal) was performed on the third day in HFDEx. An OGTT was performed after each 3-day dietary intervention.
Results. The incremental area under the curve (iAUC) of plasma glucose levels during the OGTT was significantly higher in the HFD and HFDEx trials than in the ND trial (P = 0.001). In addition, the iAUC of glucagon-like peptide-1 (GLP-1) level was significantly higher in the HFD trial than in the ND and HFDEx trials (P = 0.04). The first-phase insulin secretion indexes were significantly lower in the RED (P = 0.01 and 0.002) and HFDEx trials (P = 0.05 and 0.008) than in the ND trial.
Conclusion. A single bout of aerobic exercise did not improve the short-term HFD-induced aggravation of postprandial glucose and insulin metabolism during the OGTT. However, it did normalize the increased postprandial GLP-1 level induced by HFD. (c) 2013 Elsevier Inc. All rights reserved.

Objective: Lower birth weight is associated with higher insulin resistance in later life. The aim of this study was to determine whether cardiorespiratory fitness modifies the association of birth weight with insulin resistance in adults.
Methods: The subjects were 379 Japanese individuals (137 males, 242 females) aged 20-64 years born after 1943. Insulin resistance was assessed using a homeostasis model assessment of insulin resistance (HOMA-IR), which is calculated from fasting blood glucose and insulin levels. Cardiorespiratory fitness (maximal oxygen uptake, VO(2)max) was assessed by a maximal graded exercise test on a cycle ergometer. Birth weight was reported according to the Maternal and Child Health Handbook records or the subject's or his/her mother's memory.
Results: The multiple linear regression analysis revealed that birth weight was inversely associated with HOMA-IR (beta = -0.141, p = 0.003), even after adjustment for gender, age, current body mass index, mean blood pressure, triglycerides, HDL cholesterol, and smoking status. Further adjustments for VO(2)max made little difference in the relationship between birth weight and HOMA-IR (beta = -0.148, p = 0.001), although VO(2)max (beta = -0.376, p&lt;0.001) was a stronger predictor of HOMA-IR than birth weight.
Conclusions: The results showed that the association of lower birth weight with higher insulin resistance was little modified by cardiorespiratory fitness in adult life. However, cardiorespiratory fitness was found to be a stronger predictor of insulin resistance than was birth weight, suggesting that increasing cardiorespiratory fitness may have a much more important role in preventing insulin resistance than an individual's low birth weight.

Sumo wrestlers are a group of athletes who have high levels of fat mass and fat-free mass, not often observed in most other forms of competitive sports. Research on Sumo wrestlers may provide insight into weight gain to enhance sports performance. Regarding the energy balance of Sumo wrestlers, energy intake exceeds energy expenditure over a considerable period, for gaining weight, since Sumo wrestlers that have greater body mass possess one of the most effective ways to win. In fact, Sumo wrestlers have body weights in excess of 100 kg, with fat mass in excess of 30 kg and fat-free mass greater than 80 kg. Additionally, percent fat of the upper-leagues wrestlers ("Sekitori") remained at about 25%, and fat-free mass and the force generation capability was larger in the upper-leagues wrestlers than in the lower-leagues wrestlers. Sumo wrestlers, especially Sekitori wrestlers, can be considered to be athletes. © 2013 Elsevier Inc. All rights reserved.

The present study determined the changes in appetite and appetite-regulating gut hormones during and following bouts of both rope skipping exercise (weight-bearing) and bicycle ergometer exercise (non-weight-bearing). After a 12-h fast, 15 young men (mean ± SD, age 24.4 ± 1.7. yrs, maximal oxygen uptake 47.0 ± 6.5. mL/kg/min) participated in three 160. min trials: (1) rope skipping exercise (295 ± 40. kcal, 3 sets × 10. min with 5-min interval, then rested for 120. min)
(2) bicycle ergometer exercise (288 ± 36. kcal, 3 sets × 10. min with 5-min interval, then rested for 120. min)
(3) control (rested for 160. min). Ratings of perceived hunger and acylated ghrelin were suppressed and total peptide YY (PYY) were increased during and immediately after exercise in both exercise trials, but glucagon liked peptide-1 was not changed. Furthermore, suppressed hunger during rope skipping exercise was greater than that during bicycle ergometer exercise, but there were no differences in acylated ghrelin and total PYY. These results indicate that weight-bearing exercise has a greater exercise-induced appetite suppressive effect compared with non-weight-bearing exercise, and both forms of exercise lowered acylated ghrelin and increased total PYY, but the changes did not differ significantly between exercise modes. © 2013 Elsevier Ltd.

We investigated the effects of two carbohydrate-based sports drinks on fluid intake and immunoendocrine responses to cycling. Six well-trained male cyclists completed trials on three separate days that involved cycling at 60% V(O) over dot(2peak) for 90 min in hot conditions (28.1 +/- 1.5 degrees C and 52.6 +/- 3.1% relative humidity). During each trial, the subjects consumed ad libitum (1) an isotonic sports drink (osmolality 317 mOsm/kg), (2) a hypotonic sports drink (osmolality 193 mOsm/kg) or (3) plain water. The cyclists consumed significantly (p&lt;0.05) more of the isotonic drink (1.23 +/- 0.35 L) and hypotonic drink (1.44 +/- 0.55 L) compared with water (0.73 +/- 0.26 L). Compared with water ( 0.96 +/- 0.26 kg), body mass decreased significantly less after consuming the hypotonic drink (-0.50 +/- 0.38 kg) but not the isotonic drink (-0.51 +/- 0.41 kg). Blood glucose concentration was significantly higher at the end of the isotonic and hypotonic drink trials compared with the water trial. Neutrophil count and the plasma concentrations of catecholamines, interleukin 6 (IL-6), myeloperoxidase, calprotectin and myoglobin increased significantly during all three trials. IL-6 and calprotectin were significantly lower following the hypotonic drink trial compared with the water trial. In conclusion, hypotonic sports drinks are appealing for athletes to drink during exercise, and may help to offset fluid losses and attenuate some inflammatory responses to exercise.

The purpose of this study was to investigate the effects of low-volume exercise training (100 min/week) on oxidative stress and neutrophils activation markers in older adults. Twenty-eight older adults (age range 65-78 years) were assigned into control (n = 14) or exercise (n = 14) groups. The exercise program consisted of walking 30-60 min/session, 2 days each week for 12 weeks. Blood samples were taken before starting the sessions (baseline) and when they ended. Fasting plasma and serum oxidative stress and inflammatory markers were measured using commercial kits. Cell surface expression of adhesion molecules on circulating leukocytes (CD66b and CD62L) was determined using flow cytometry. The concentrations of derivatives of reactive oxygen metabolites tended to be lower than the baseline values only in the exercise group (P = 0.05). The biological antioxidant potential, thioredoxin concentrations, and glutathione peroxidase activities significantly increased only in the exercise group (P < 0.05 for all). While CD66b expression tended to decrease only in the exercise group, CD62L expression significantly increased (P < 0.05). Our findings indicate that exercise training below the current recommended level of at least 150 min/week attenuates basal oxidative stress and neutrophil activation in older adults. Thus, our findings may encourage more people to incorporate a small amount of physical activity into their lives.

The aim of this study was to investigate the effects of sleep deprivation on autonomic and endocrine functions during the day and on exercise tolerance in the evening. Ten healthy young males completed two, 2-day control and sleep deprivation trials. For the control trial, participants were allowed normal sleep from 23:00 to 07:00 h. For the sleep deprivation trial, participants did not sleep for 34 h. Autonomic activity was measured from 19:00 h on day 1 to 16:00 h on day 2 by frequency-domain measures of heart rate variability. Endocrine function was examined by measuring adrenocorticotropic hormone and cortisol from venous blood samples collected on day 2 at 09:00, 13:00, and 17:00 h and immediately after an exercise tolerance testing. Autonomic regulation, particularly parasympathetic regulation estimated from the high-frequency component of heart rate variability analysis, was significantly higher in the sleep deprivation trial than in the control trial in the morning and afternoon of day 2. Plasma adrenocorticotropic hormone concentrations were significantly higher at 09:00 and 13:00 h of day 2 under sleep deprivation. Heart rate during exercise was significantly lower following sleep deprivation. Therefore, the effects of sleep deprivation on autonomic regulation depend on the time of the day. © 2013 Copyright Taylor and Francis Group, LLC.

Oxidative stress increases with advancing age and is a mediator of several diseases including cancer, cardiovascular disease, and diabetes. Moreover, postmenopausal women have a lower estrogen concentration, which is associated with elevated oxidative stress. However, there is no definitive evidence regarding the relationship between daily physical activity and oxidative stress status in older adults, including postmenopausal women. Twenty- nine adults (age, 70.1 ± 1.0 years, mean ± SE; 12 women and 17 men) were examined in this cross-sectional study. Prior to blood collection, the participants were asked to wear a uniaxial accelerometer for 4 consecutive weeks to determine their level of physical activity. After a 48-h period of physical activity avoidance and a 10-h overnight fast, venous blood samples were obtained from each participant. Fasting plasma derivatives of reactive oxygen metabolites (d-ROMs) and malondialdehyde (MDA) concentrations of oxidative stress markers were negatively correlated with the amount of physical activity in women (d-ROMs; r = -0.708, p = 0.002) (MDA; r = -0.549, p = 0.028), but not in men. Fasting plasma biological antioxidant potential of antioxidant capacity marker was positively correlated with the amount of physical activity in women (BAP; r = 0.657, p = 0.006) (GSH; r = 0.549, p = 0.028), but not in men. Moreover, superoxide dismutase activity of antioxidant capacity marker was positively correlated with the amount of physical activity in men (r = 0.627, p = 0.039), but not in women. There were no associations between physical activity and other oxidative stress markers (reduced and oxidized glutathione, glutathione peroxidise, thioredoxin). These findings suggest that regular physical activity may have a protective effect against oxidative stress by increasing total antioxidant capacity, especially in postmenopausal women. © Journal of Sports Science and Medicine.

:The purpose of this study was to investigate the effects of low-volume exercise training (90 min/wk) and vitamin E supplementation on oxidative stress markers in postmenopausal women. The participants were non-randomly assigned the following four groups: control (C, n=8), vitamin E (S, n=8), exercise (Ex, n=6), or vitamin E and exercise (S+Ex, n=7). The S and S+Ex groups were instructed to take vitamin E (α-tocopherol, 300 mg/d) capsules for 12 wk. The exercise program of Ex and S+Ex groups consisted of walking for a 30-60 min/session 2 d per week for 12 wk. The serum derivatives of reactive oxygen metabolites concentrations were significantly decreased in the Ex, and S+Ex groups after 12 wk compared with the baseline values (three-factor ANOVA, an interaction between exercise and time, p&lt;0.05). Conversely, serum biological antioxidant potential concentrations in the S and Ex groups were significantly higher at 12 wk than at the baseline, but not in the S+Ex group (three-factor ANOVA, an interaction between supplementation, exercise and time, p&lt;0.05). Plasma thioredoxin concentrations in the S, Ex, and S+Ex groups were significantly higher at 12 wk than at the baseline values (th

The aim of this study was to investigate the effects of one night of sleep deprivation on maximal fat oxidation during a graded exercise test. Ten healthy young males underwent two 2-day control and sleep deprivation trials. Participants were allowed normal sleep from 2300 to 0700 for the control trial, whereas they were required to stay awake for 34 h during the sleep deprivation trial. At 1700 on day 2, participants performed a graded exercise test to exhaustion on a treadmill; this allowed us to determine maximal oxygen uptake and maximal fat oxidation. Before and immediately after the graded exercise test, blood samples were collected in order to measure glucose, insulin, free fatty acid, and triglyceride concentrations. Plasma glucose concentrations were significantly higher in the sleep deprivation trial than in the control trial before the graded exercise test. Serum insulin and free fatty acid concentrations were not significantly different between the two trials. Serum triglyceride concentrations were significantly lower in the sleep deprivation trial than in the control trial. The maximal fat oxidation rate, oxygen uptake, and heart rate at maximal fat oxidation intensity, during the graded exercise test, were not significantly different between the two trials. These findings suggest that maximal fat oxidation during graded exercise is unaffected by one night of sleep deprivation.

BACKGROUND/OBJECTIVES: Postprandial hyperglycemia increases the risks of development of type 2 diabetes and cardiovascular diseases. The purpose of this study was to determine whether a 3-day low-carbohydrate/high-fat diet (LC/HFD) alters postprandial plasma glucose and incretin levels during oral glucose tolerance test (OGTT) in healthy men.
SUBJECTS/METHODS: Nine healthy young men (age (mean +/- s.e.), 27 +/- 1 years; body mass index, 22 +/- 1 kg/m(2)) consumed either a normal diet (ND: energy from similar to 22% fat) or a LC/HFD (energy from similar to 69% fat) for 3 days each. The total energy intake from each diet was similar. An OGTT was performed after each 3-day dietary intervention. Postprandial plasma glucose, insulin, free fatty acid and glucagon-like peptide-1 (GLP-1) levels were determined at rest and during the OGTT.
RESULTS: Plasma glucose levels and incremental area under the curve during the OGTT were significantly higher in the LC/HFD trial than in the ND trial (P = 0.024). In addition, increase in GLP-1 levels was significantly higher in the LC/HFD trial than in the ND trial (P = 0.025). The first-phase insulin secretion indexes were significantly lower in the LC/HFD trial than in the ND trial (P &lt; 0.041).
CONCLUSIONS: These results demonstrate that even short-term LC/HFD increased postprandial plasma glucose and GLP-1 levels in healthy young men. A decrease in first-phase insulin secretion may partially contribute to the short-term LC/HFD-induced increase in postprandial plasma glucose levels.

Background: When previously sedentary males and females follow the same exercise training programs with ad libitum feeding, males reduced body mass, but females do not, which suggests that females may increase appetite in response to exercise training compared with males. Rope skipping is traditional exercise modality that everyone had experienced during elementary school years in Japan. The purpose of this study was to determine whether there is a sex difference on appetite after acute rope skipping exercise.
Methods and results: Thirteen healthy young males (22.5 +/- 0.8 years, 172.2 +/- 1.7 cm, 68.8 +/- 2.3 kg, 18.4 +/- 0.9%) and 13 females (22.9 +/- 0.8 years, 160.6 +/- 1.5 cm, 52.9 +/- 1.6 kg, 25.0 +/- 1.0%) participated in this study. Subjects consumed their lunch by 13:00, and performed a total of 20 min rope skipping exercise (2 sets x 10 min with 5 min interval) from 16:00. In females, appetite significantly increased from immediately after the exercise to 30 min after the exercise (from 13 mm to 30 mm), but remained unchanged in males. Although heart rate, ratings of perceived exertion, and lactate concentrations increased from baseline to immediately after exercise, there were no differences in the increase between males and females. Blood glucose concentrations at baseline and 30 min after exercise were higher in females than in males.
Conclusion: These results indicated that rope skipping exercise induces an increase in appetite in females, but not in males. This increased appetite in females after the rope skipping exercise was induced without change in blood glucose concentrations. (C) 2011 Asian Oceanian Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.

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 &lt; 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 purpose of this study was to investigate the effects of three different intensities of exercise on oxidative stress and antioxidant capacity. Eight healthy male subjects performed three different intensities of exercise for 20 minutes: (1) 70% anaerobic threshold (AT) (light intensity, LI), (2) 100% AT (moderate intensity, MI), and (3) 130% AT (high intensity, HI) on a cycle ergometer. A control (C) trial was conducted under resting conditions. Blood samples were taken pre-exercise, immediately and 30 min after exercise. In the HI trial only, the concentrations of plasma derivatives of reactive oxygen metabolites (d-ROMs) were significantly higher immediately (P<0.01) and 30 min after exercise (P<0.05) than at pre-exercise. Furthermore, plasma trolox equivalent antioxidant capacity was significantly higher immediately after exercise in the HI trial (P<0.01). And, plasma glutathione peroxidase (GPX) activity was significantly higher immediately after exercise than at pre-exercise in the MI (P<0.05) and HI trials (P<0.01). These data suggest that 20 min of pedaling exercise above the AT level may increase ROS production, while endogenous enzyme activity (especially GPX activity) or non-enzymatic antioxidants may modulate exercise-induced ROS generation. Thus, exercise under the AT level induces very little oxidative stress damage in young people.

The present study was performed to develop regression-based prediction equations for fat mass by ultrasound in Japanese children and to investigate the validity of these equations. A total of 127 healthy Japanese pre-pubertal children aged 6-12 years were randomly separated into two groups: the model development group (fifty-four boys and forty-four girls) and the validation group (eighteen boys and eleven girls). Total body, trunk, arm and leg fat masses were initially determined by dual-energy X-ray absorptiometry (DXA, Delphi A-QDR whole-body scanner; Hologic, Inc., Bedford, MA, USA). Then, fat thickness was measured by B-mode ultrasound (5 MHz scanning head) at nine sites (arm: lateral forearm, anterior and posterior upper arm; trunk: abdomen and subscapular; leg: anterior and posterior thigh, anterior and posterior lower leg). Regression analyses were used to describe the relationships between the site-matched fat masses (total body, arm, trunk and leg) obtained by DXA and ultrasound in the development group. When these fat mass prediction equations were applied to the validation group, the measured total and regional fat mass was very similar to the predicted fat mass (mean difference calculated as predicted - measured fat mass +/-2 SD; total body 0.1 (SD 0.5) kg, arm 0.1 (SD 0.3) kg, trunk -0.1 (SD 0.3) kg, leg 0.1 (SD 0.5) kg for boys; total body 0.5 (SD 1.3) kg, arm 0.0 (SD 0.3) kg, trunk 0.1 (SD 0.8) kg, leg 0.3 (SD 0.6) kg for girls), and the Bland-Altman analysis did not indicate a bias. These results suggest that ultrasound-derived prediction equations for boys and girls are useful for estimating total and regional fat mass.

We examined whether cardiorespiratory fitness (maximal oxygen uptake, &lt;(V)over dot&gt;O(2)max) and muscular strength (grip strength) are associated with individual and clustered metabolic risk factors independently of abdominal adiposity in Japanese men (n=110) and women (n=110) aged 20-69 years. Blood pressure, triglycerides (TG), HDL cholesterol, and fasting plasma glucose (FPG) were assessed and metabolic risk score was calculated, which is the sum of the z scores for each individual risk factor. Waist circumference was measured and the area of visceral fat was assessed by MRI. Multiple linear regression analysis revealed that &lt;(V)over dot&gt;O(2)max was inversely associated with TO in men (p&lt;0.05) and grip strength was negatively associated with FPG and metabolic risk score in women (p&lt;0.001 and p&lt;0.05, respectively), independently of waist circumference. Adjusting for visceral fat instead of waist circumference, similar results were obtained in women (p&lt;0.01 and p&lt;0.05, respectively), but the association between &lt;(V)over dot&gt;O(2)max and TO in men was attenuated to nonsignificant. This cross-sectional study demonstrates that muscular strength is inversely associated with plasma glucose levels and clustered metabolic risk factors independently of abdominal adiposity in Japanese women, but not in men. J Physiol Anthropol 30(4): 133-139, 2011 http://www.jstage.jst.go.jp/browse/jpa2 [DOI: 10.2114/jpa2.30.133]

The purpose of this study was to examine effects of moderate-intensity endurance exercise on reactive oxygen species production and leukocyte activation markers in young and middle-aged persons. Blood samples were collected before and after the jogging of 10 km. Although cytokines recruiting and priming neutrophils and monocytes were released into the circulation and functional after the jogging of 10 km, reactive oxygen metabolites-derived compounds (d-ROMs) were not significantly increased. It was indicated that chemokines and leukocyte activation markers at rest were increased with aging, and that might be accompanied by the higher level of d-ROMs in the elderly.<br>

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 &lt; 18.5 kg/m(2)) and 20 normal women (18.5 &lt;= BMI &lt; 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.

The present study was performed to develop regression based prediction equations for fat mass from skinfold thickness in Japanese children, and to investigate the cross-sectional and longitudinal validity of these equations. A total of 127 healthy Japanese prepubertal children aged 6-12 years were randomly separated into two groups: the model development group (54 boys and 44 girls) and the cross-sectional validation group (18 boys and 11 girls). Fat mass was initially determined by using DXA (Hologic Delphi A-QDR whole-body scanner) to provide reference data. Then, fat thickness was measured at triceps and subscapular using an Eiken-type skinfold calipers. Multiple anthropometric and DXA measures were obtained one year later for 28 of the original 127 subjects (longitudinal validation group: 14 boys and 14 girls). Strong significant correlations were observed between total fat mass by DXA measurement and the skinfold thickness x height measures by caliper in the model development group of boys and girls (R(2)=0.91-0.92, p&lt;0.01). When these fat mass prediction equations were applied to the cross-sectional and longitudinal validation groups, the measured total fat mass was also very similar to the predicted fat mass. In addition, there were significant correlations between the measured and predicted total fat mass for boys and girls, respectively, although Bland-Altman analysis indicated a bias in cross-sectional validation group. Skinfold-derived prediction equations underestimate for obese children but are generally useful for estimating total fat mass in field research.

Abdominal adiposity and low cardiorespiratory fitness are assosicated with insulin resistance in people with impaired glucose tolerance and type 2 diabetes. However, little is known about which factor precedes insulin resistance in people with impaired glucose tolerance and type 2 diabetes, and which is the stronger predictor of insulin resistance in non-diabetic people. The purpose of this study was to examine the relationship between insulin resistance and cardiorespiratory fitness, visceral fat, and subcutaneous fat in nondiabetic people. Subjects included 87 men and 77 women aged 30-72 y (mean +/- SD, 51.3 +/- 12.3 y). Cardiorespiratory fitness was assessed by measuring the maximal oxygen uptake ((V) over doto(2max)) in a progressive continuous test to exhaustion on a cycle ergometer. The visceral and subcutaneous fat areas were measured by magnetic resonance imaging. The homeostasis model assessment of insulin resistance (HOMA-R) was calculated from the fasting concentrations of glucose and insulin. Stepwise multiple linear regression analysis revealed that visceral and subcutaneous fat were significant correlates of HOMA-R, explaining 24% and 6% of the variance, respectively, whereas sex, age, and (V)over doto(2max) were not significant independent determinants. Abdominal fat deposition rather than cardiorespiratory fitness is a significant predictor of insulin resistance in non-diabetic people; visceral fat is the most important factor.

日本人中高年男性と対象に、最大酸素摂取量と身体活動量との関係を明らかにし、最大酸素摂取量と強い強度の身体活動との関係性について検討した。その結果、3METs以上の身体活動量は年齢や腹囲とは独立した心肺体力の関連因子であること、とりわけ、6METs以上で実施された身体活動量が、心肺体力に寄与していることが明らかになった。

PURPOSE:This study aimed to investigate the relation between cardiorespiratory fitness(CRF) and physical activity, especially vigorous physical activity, in Japanese middle-aged and elderly men. METHODS:Eighty-five men aged 30-69 years participated in this study. CRF was assessed by measuring the maximal oxygen uptake based on weight (V̇O2max/wt) in an incremental test on a bicycle ergometer. METs ·
h/week was measured as the parameter of physical activity by using accelerometers. We defined the amount of physical activity higher than 3 METs as "Physical activity
PA" in this study. Then, PA was divided into "Moderate physical activity
MPA"(higher than 3 METs and below 6 METs) and "Vigorous physical activity
VPA" (higher than 6 METs). RESULTS:CRF was positively correlated with PA(r=0.318, P&lt
0.01), MPA(r=0.230, P&lt
0.05), and VPA(r=0.301, P&lt
0.01) and negatively correlated with age(r=-0.607, P&lt
0.001), BMI(r= -0.369, P&lt
0.01), and waist circumference(WC) (r=-0.486, P&lt
0.001). After adjusting for age and WC, the multiple regression analysis revealed that PA was positively correlated with CRF(P&lt
0.01). VPA was positively correlated with CRF(P&lt
0.05) after adjusting for age, WC, and MPA. MPA was not correlated with CRF in the case of adjusting for age and WC. CONCLUSION:This study suggested that physical activity higher than 3 METs was positively associated with cardiorespiratory fitness independently of age and waist circumference, and particularly vigorous physical activity may contribute to increased cardiorespiratory fitness in middle-aged and elderly men. Thus physically active life with maintenance of adequate waist circumference may help to prevent age-related decline in cardiorespiratory fitness.

PORPOSE: This study aimed to compare the prevalence of metabolic syndrome (MS) risk factors and its components in different levels of aerobic fitness established by &ldquo;Exercise and Physical Activity Reference for Health Promotion 2006 (EPAR2006)&rdquo; in Japanese middle-aged and elderly people.<br>METHOD: Men (n=102) and women (n=133), aged 30-69yrs, participated in this study. The prevalence of MS risk factors was evaluated as the number of MS risk factors, according to the diagnostic criterion for Japanese-specific MS. Aerobic fitness was quantified as maximal oxygen uptake (VO₂max). Subjects were classified into the three groups by aerobic fitness level based on &ldquo;Reference values&rdquo; and &ldquo;Reference range&rdquo; established in EPAR2006; 1) High fitness group (H); VO₂max (mL/kg/min) is higher than &ldquo;Reference values&rdquo;, 2) Medium fitness group (M); VO₂max is below &ldquo;Reference values&rdquo; but within &ldquo;Reference range&rdquo;, 3) Low fitness group (L); VO₂max is lower than &ldquo;Reference range&rdquo;.<br>RESULTS: In men, M and L groups showed significantly higher frequency of risk factors for MS than H group (H: 1.09&plusmn;0.98, M: 1.81&plusmn;1.07, L: 2.27&plusmn;0.70, P＜0.01). In women, L group showed significantly higher frequency of risk factors for MS than H and M groups (H: 0.57&plusmn;0.80, M: 0.81&plusmn;1.01, L: 1.53&plusmn;1.07, P＜0.01).<br>CONCLUSION: These results suggest that higher MS risk appears when the VO₂max is lower than &ldquo;Reference values&rdquo; in men, and below &ldquo;Reference range&rdquo; in women, and that particularly, men with low aerobic fitness have higher MS risk.

We have previously reported the preventive effects of light resistance exercise (voluntary tower climbing exercise) after ingestion of a high-protein snack (HPS) on muscle loss in glucocorticoid-injected rats. However, such studies have not been performed in humans. In this cross-over study, we examined the effect of light resistance exercise after ingestion of HPS on plasma branched-chain amino acid (BCAA) concentrations in humans. Seven healthy young adult females (aged 22.1 +/- 1.2 y) participated in this study. They were assigned to either an exercise group or a control group. Seven days after the first experiment. they were crossed over to the opposite intervention. The subjects ingested RPS (15 g protein, 18 g sugar) 3 h after breakfast (basal meal). The plasma BCAA concentrations increased at 30 min after HPS ingestion. The subjects in the exercise group performed light resistance exercise (15 min dumbbell exercise using 300 g brown-rice-filled fabric dumbbells) when the plasma BCAA concentrations were increased (60 min after the snack ingestion). The control group maintained a resting position during the experiment. Changes in the plasma BCAA concentrations between 60 and 90 min after HPS ingestion increased continuously in the control group (+27 mu mol/L) but decreased in the exercise group (-37 mu mol/L. Therefore. light resistance exercise after HPS ingestion may be effective for utilization of plasma BCAA in humans.

Athletes have been instructed to refrain from taking carbonated beverages in the sports world, but the mechanism has not been clear. The purpose of this study was to clarify how physiological and biochemical evaluation are affected by taking a 10% CHO carbonated beverage after cycle ergometer (60 min, 60% &lt;(V)over dot &gt; O(2)max). Seven subjects consumed a carbonated or noncarbonated (10% carbohydrate) beverage after exercise. No differences were observed in concentration of glucose, insulin, free fatty acids, K and Na in serum from carbonated beverage compared with noncarbonated beverage intakes after exercise.
These results indicate that carbonated beverage did not affect the changes of physiological and biochemical parameter after prolonged exercise, and it could be more refreshing and stimulate taste rather than noncarbonated beverage, but seemed to be hard to drink immediately after exercise because it made subjects feel as if having drunk more than they did.

[Objective] The present study aimed to examine whether waist circumference (WC) and waist/height ratio (WHtR) are useful indicators for determining visceral fat obesity in young women, and the relation of these indicators with coronary risk factors. [Subjects and Methods] 42 women aged 21-30 years who received medical checkup were studied. The subjects underwent blood sampling under fasting, body composition measurement, resting electrocardiography, pulse wave velocity measurement. The correlation between percent body fat and WC or WHtR was examined. The correlation between coronary risk factors and WC or WHtR was analyzed. [Results] A strong positive correlation was observed between percent body fat and WC [r = 0.77] and between percent body fat and WHtR (r = 0.75). Among the coronary risk factors examined, only HDL-cholesterol showed a strong negative correlation with WC (r = -0.49) and with WHtR (r = -0.45). [Conclusions] WC and WHtR are useful to determine obesity or visceral fat obesity even in young female adults. But WC and WHtR are limited in predicting the status of coronary risk factor in young female adults.

[Subjects and Methods] Fifty-eight male subjects (mean age: 52.0 years) who underwent HDL-cholesterol subfraction and exercise stress tests were recruited. Many subjects were obese and had hyperlipemia et al.. Thirteen were taking anti-hyperlipemic drugs. Frequency of aerobic exercise practice was graded. [Results and Conclusions] The relations between changes of exercise frequency and changes of HDL2-C levels were as follows: HDL2-C levels increased in 14 of 19 measurements with increased exercise frequencies; HDL2-C levels increased in 24 of 41 measurements with unchanged exercise frequencies; HDL2-C levels decreased in 11 of 16 measurements with reduced exercise frequencies. Taking anti-hyperlipemic drugs had no effect on HDL2-C levels. The HDL2-C level strongly correlate with the frequency of aerobic exercise practice, but is independent of the effect of anti-hyperlipemic drugs.