The aim of this study was to evaluate the level of physical activity and cardiorespiratory fitness in teenagers with type 1 diabetes mellitus (T1D) in comparison with healthy scholar participants. Total of 154 teenagers (T1D = 45 and CON = 109). Height, weight, cardiorespiratory fitness (VO_2max), and the level of physical activity by the Bouchard’s Physical Activity Record were measured, and glycated hemoglobin (HbA1c) in T1D. The VO_2max was lower in the T1D (38.38 ± 7.54) in comparison with the CON (42.44 ± 4.65; p < .05). The VO_2max had correlation with the amount of time of moderate-to-vigorous physical activity (r = .63; p = .0001) and an inverse correlation with sedentary activities (r= -0.46; p = .006). In the T1D the levels of HbA1c had an inverse correlation with the amount of time of moderate-to-vigorous physical activity (r= -0.34; p = .041) and correlation with the BMI z-score (r = .43; p = .017). Only 37,8% of the participants in the T1D reached the adequate amount of daily moderate-to-vigorous intensity physical activity, in the CON 81,7% reached the WHO’s recommendation. Conclusion: T1D had less cardiorespiratory capacity then healthy controls, the teenagers of T1D with lower BMI z-score and that dedicated a greater time in moderate-to-vigorous intensity physical activity demonstrated a better glycemic control.