Low-volume high-intensity interval training reduces hyperglycemia and increases muscle mitochondrial capacity in patients with type 2 diabetes.

摘要

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, body mass index 32 +/- 6 kg/m(2), Hb(A1C) 6.9 +/- 0.7%) volunteered to participate in this study. Participants performed six sessions of HIT (10 x 60-s cycling bouts eliciting approximately 90% maximal heart rate, interspersed with 60 s rest) over 2 wk. Before training and from approximately 48 to 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 was 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 ( approximately 20%) and protein content of Complex II 70 kDa subunit ( approximately 37%), Complex III Core 2 protein ( approximately 51%), and Complex IV subunit IV ( approximately 68%, all P < 0.05). Mitofusin 2 ( approximately 71%) and GLUT4 ( approximately 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.