Acute and chronic glycemic effects of aerobic training in patients with type 2 diabetes

The aim of the present study was to analyze acute glycemic effects in different moments of an aerobic training, as well as to analyze the chronic effect of training, in patients with type 2 diabetes mellitus (T2D). The participants performed 16 weeks of interval aerobic training with three weekly sessions. The main part of each session consisted of nine blocks of five minutes, in which four minutes consisted of stimulus between 85% and 95% of the anaerobic threshold heart rate (ATHR) and one minute consisted of recovery below 85% of the ATHR, totalizing 45 minutes. Capillary glucose was assessed before, immediately after and 30 minutes after the first and the last training sessions. Glycated hemoglobin (HbA1c) was assessed before and after the intervention. Paired t-test and Generalized Estimating Equations were performed for the analyses; α = 5%. The participants were seven individuals (four women) aged 59.60±6.69 years. In the first session, glucose values immediately after and 30 minutes after exercise were lower than pre-exercise values. On the other hand, in the last training session, only the glucose values immediately after exercise were lower than pre-exercise values. Analyzing the glycemic reductions, the first session presented a greater reduction immediately after (p = 0.042) and 30 minutes after exercise (p = 0.010). Regarding chronic glycemic effects, an increase (p = 0.010) in HbA1c levels was observed after training. It is concluded that, after 16 weeks of training without progression of duration and intensity, the exercise loses its acute glycemic effect, and may be even insufficient to reduce HbA1c levels.