Can Time Efficient Exercise Improve Cardiometabolic Risk Factors in Type 2 Diabetes? A Pilot Study.

Exercise is considered a cornerstone in the prevention and treatment of type 2 diabetes, but few individuals with type 2 diabetes exercise according to guidelines. We investigated the effect of two time efficient high intensity exercise interventions on exercise capacity, glycemic control and other cardiometabolic risk factors in patients with type 2 diabetes. Twenty-one individuals with type 2 diabetes were randomly assigned to low volume high intensity interval exercise (HIIE; 27 minutes/bout; 10x1-minute at 90 % of HRmax; n = 10) or extremely low volume sprint interval exercise (SIE; 10 minutes/bout; 2x20 seconds at maximum achievable intensity; n = 11) 3 days/week for 12 weeks. Aerobic exercise capacity (VO2peak), glycosylated hemoglobin (HbA1c), blood pressure and body composition were measured at baseline and post test. Both HIIE and SIE improved VO2peak (3.3 mL·min(-1)·kg(-1), 10.4 %), p < 0.01, and 1.4 mL·min(-1)·kg(-1) (4.6 %), p = 0.03, respectively). Only HIIE reduced body fat percentage (4.5 %, p = 0.04) and two minute heart rate recovery (11.0 bpm, p = 0.02). Neither HIIE nor SIE improved HbA1c. In conclusion, this study indicates that substantially lower exercise volumes than recommended in current guidelines can improve aerobic exercise capacity in individuals with type 2 diabetes. However, 12 weeks of time efficient high intensity exercise did not improve glycemic control, and interventions of longer duration should be investigated. Key pointsLow volume high-intensity interval exercise can improve peak oxygen uptake in previously sedentary individuals with type 2 diabetesThe weekly exercise volumes in the two intervention groups of 81 and 30 minutes respectively, is substantially lower than recommended in current exercise guidelines and could reduce the time-barrier associated with exercise among patients with type 2 diabetes.However, 12 weeks of structured, supervised low-volume exercise did not improve glycemic control, indicating a need for exercise volumes or longer intervention period.