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 (VO2max), and the level of physical activity by the Bouchard’s Physical Activity Record were measured, and glycated hemoglobin (HbA1c) in T1D. The VO2max was lower in the T1D (38.38 ± 7.54) in comparison with the CON (42.44 ± 4.65; p < .05). The VO2max 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.