Physical training is recommended in several studies and guidelines for the control of type 2 diabetes mellitus (DM2) and its complications. We performed a systematic review about the effects of aerobic training (AT), resistance (RT) or the combination of both (AT/ RT), on glycated hemoglobin (HbA1c) in patients with DM2. Therefore, we included 15 clinical trials with at least 12 weeks duration about training program or recommendations of physical exercise, that evaluated the reduction in HbA1c levels in patients with DM2. Information was obtained on training modality (AT, RT or AT / RT), training parameters, duration and weekly training frequency. The results showed increases in peak or maximal oxygen uptake, exercise tolerance time and muscle strength, depending on the type of training, and a reduction in HbA1c levels. We conclude that exercise training is associated with reductions of HbA1c in patients with DM2. Thus, it can be a complementary tool in the management of these patients.