The most common type of diabetes among children and adolescents is type 1 diabetes mellitus (T1DM), which is associated with an increased risk of cardiovascular disease (CVD). Additionally, lower levels of cardiorespiratory fitness (CRF) are linked to an increased risk of CVD. Regular exercise is associated with a decreased risk of CVD and improved CRF. We conducted this scoping review to assess the effects of exercise on CRF in youth with T1DM. Three electronic databases (PubMed, Embase, and Cochrane Central Register of Controlled Trials) were used to search for the relevant literature. In this analysis, the PICOS method was used to select studies and was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Guidelines scoping review guidelines for the evaluation of the effects of physical activity and cardiac function; the criteria may include the type and intensity of physical activity, the duration of the intervention, peak oxygen consumption (VO2), peak minute ventilation (VE), and peak heart rate of cardiorespiratory fitness. Screening resulted in 434 records. Of these, nine articles were included in our study. These nine studies were experimental (noncontrolled trials or randomized controlled trials) (n = 7) and observational (cross-sectional) (n = 2), and could be used to evaluate the effectiveness of physical activity interventions on cardiac function. The effects of exercise on CRF in youth with T1DM vary according to the type, frequency, and intensity of the exercise. According to our review, the duration of exercise included in the studies did not meet the recommendations of the guidelines for youth with T1DM. Additionally, half of the studies revealed that exercise could optimize the lipid profile in youth with T1DM. Hence, this research is to provide an overview of the effects of physical activity and exercise on CRF, cardiovascular fitness, lipid profile, and blood pressure in youth with T1DM, as well as identified potential limitations of the existing studies. Nevertheless, the limited number of clinical studies employing exercise interventions for children and adolescents with T1DM emphasize the need for more studies in this area, and more specific modes of exercise should be developed in the future.