Low-volume high-intensity interval training (HIT) is emerging as a time-efficient exercise strategy for improving health and fitness. This form of exercise has not been tested in type 2 diabetes and thus we examined the effects of low-volume HIT on glucose regulation and skeletal muscle metabolic capacity in patients with type 2 diabetes. Eight patients with type 2 diabetes (63±8 yr, BMI 32±6 kg/m2, HbA1C 6.9±0.7%) volunteered to participate in this study. Participants performed six sessions of HIT (10 x 60 s cycling bouts eliciting ~90% maximal heart rate, interspersed with 60 s rest) over 2 wk. Before training and from ~48-72 h after the last training bout, glucose regulation was assessed using 24-h continuous glucose monitoring under standardized dietary conditions. Markers of skeletal muscle metabolic capacity were measured in biopsy samples (vastus lateralis) before and after (72 h) training. Average 24-h blood glucose concentration was reduced after training (7.6±1.0 vs 6.6±0.7 mmol/L) as were the sum of the 3-h postprandial areas under the glucose curve for breakfast, lunch and dinner (both p<0.05). Training increased muscle mitochondrial capacity as evidenced by higher citrate synthase maximal activity (~20%) and protein content of Complex II 70 kDa subunit (~37%), Complex III Core 2 protein (~51%), and Complex IV subunit IV (~68%, all p<0.05). Mitofusin 2 (~71%) and GLUT4 (~369%) protein content were also higher after training (both p<0.05). Our findings indicate that low-volume HIT can rapidly improve glucose control and induce adaptations in skeletal muscle that are linked to improved metabolic health in patients with type 2 diabetes.
- Continuous Glucose Monitoring
- Glycemic Control
- Copyright © 2011, Journal of Applied Physiology