Effect of high versus low-intensity supervised aerobic and resistance training on modifiable CVD risk factors in T2DM subjects

PURPOSE: There is no clear evidence indicating that moderate-to-high intensity (HI) training provides more benefits than low-to-moderate intensity (LI) training of equal energy cost on glycemic control and other modifiable CVD risk factors in individuals with type 2 diabetes. This study was aimed at verifying this hypothesis in a large cohort of the Italian Diabetes and Exercise Study (IDES). METHODS: Sedentary patients with type 2 diabetes and the metabolic syndrome were enrolled in 22 outpatient diabetes clinics across Italy and randomized to twice-a-week supervised progressive aerobic and resistance training plus exercise counseling (exercise group; n=303) versus counseling alone (control group; n=303) for 12 months. Individuals in the exercise group were further randomized to LI aerobic (at 55% of predicted maximal oxygen consumption [VO2max]) and resistance (at 60% of predicted 1-Repetition Maximum [RM]) training (n=142) versus HI aerobic (at 70% of predicted VO2max) and resistance (at 80% of predicted 1-RM) training (n=161). RESULTS: Volume of physical activity, both supervised and non-supervised, was similar in LI and HI participants. Compared with LI training, HI training produced only marginal, though statistically significant, improvements in strength, HbA1c (mean difference -0.17% [0.10;-0.43], P=0.03), triglycerides (-10.36 mg/dl [9.10;-29.82], P=0.02) and total cholesterol (-9.23 mg/dl [-0.53;-17.94], P=0.04), but not in the other parameters examined. CONCLUSIONS: Data from the IDES indicate that, in low-fitness individuals such as sedentary subjects with type 2 diabetes, intensity is less important than volume and type of exercise for achieving improvements in modifiable cardiovascular risk factors.