High-Intensity Intervallic Exercise (HIIE) Is Superior to Isocaloric Moderate-Intensity Continuous Exercise (MICE) at Reducing Postprandial Hyperglycemia.

Purpose: We investigated if a bout of high-intensity intervallic exercise (HIIE) is more efficacious at reducing postprandial hyperglycemia than an isocaloric bout of moderate-intensity continuous exercise (MICE).

Methods: Nineteen healthy physically active individuals (21% women) completed three trials in a randomized order: i ) HIIE cycling consisting of five bouts of 4 min at 83 ± 9% of subjects' maximal oxygen consumption ( O 2MAX ) with active recoveries at 53 ± 8%, for a total of 50 min; ii ) MICE cycling at 65 ± 8% of O 2max for 50 min; and iii ) CONTROL no exercise. All trials were followed by a standard oral glucose tolerance test (OGTT) ingesting 74 g of glucose traced with 1 g of uniformly labeled [ 13 C]-glucose. Plasma glucose and insulin concentrations, and plasma glucose kinetics ([6,6 2 H 2 ] glucose infusion) were measured before exercise, during exercise, and during the OGTT. Insulin sensitivity was estimated by the Matsuda index (ISI). Energy expenditure and carbohydrate oxidation (CHOxid) were monitored.

Results: At rest, blood glucose, insulin concentrations, and CHOxid were similar in all three trials. During exercise, energy expenditure was similar in HIIE versus MICE (548 ± 131 vs 560 ± 125 kcal; P = 0.340). However, CHOxid, plasma glucose concentration, and its rates of appearance in plasma (Ra) were higher in HIIE versus MICE (Ra glucose 34.3 ± 9.8 vs 28.9 ± 6.8 μmol·kg -1 ·min -1 ; P = 0.021). During the OGTT, plasma glucose and insulin concentrations were lower, and insulin sensitivity was higher in HIIE versus CONTROL (ISI MATSUDA ; 12.4 ± 4.7 vs 10.8 ± 4.7 au; P = 0.007). Exercise delayed blood incorporation of [ 13 C]-glucose into blood ( P = 0.023). Early during the OGTT, glucose clearance rates were higher in HIIE versus CONTROL (7.1 ± 3.1 vs 5.5 ± 3.0 mL·kg -1 ·min -1 ; P = 0.015).

Conclusions: HIIE is more effective than MICE to reduce hyperglycemia and hyperinsulinemia after glucose ingestion. HIIE improves glycemic control by increasing splanchnic glucose retention and glucose clearance rates.