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

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).

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.

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).

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.