Glucose response to exercise in the post-prandial period is independent of exercise intensity.

Abstract

This study investigated the acute glucose response to low-intensity, moderate-intensity, and high-intensity interval exercise compared to no-exercise in healthy insufficiently active males using a four-arm, randomized, crossover design. Ten males (age: 37.3±7.3years, BMI: 29.3±6.5kg·m-2 ) completed four 30-minute interventions at weekly intervals comprising low-intensity exercise (LIE) at ~35% V˙O2 R, moderate-intensity exercise (MIE) at ~50% V˙O2 R, high-intensity interval exercise (HIIE) at ~80% V˙O2 R, and a no-exercise control. Participants performed cycle ergometer exercise 30minutes after finishing breakfast. Glucose response was assessed using a continuous glucose monitor under free-living conditions with dietary intake replicated. A significant effect for intensity on energy expenditure was identified (P<.001) with similar energy cost in MIE (mean±SD: 869±148kJ) and HIIE (806±145 kJ), which were both greater than LIE (633±129kJ). The pattern of glucose response between the interventions over time was different (P=.02). Glucose was lower 25minutes into each of the HIIE, MIE and LIE trials respectively (mean difference±SD: -0.7±1.1; -0.9±1.1; -0.6±0.9mmol·L-1 ; P<.05) than in the no-exercise trial. Glucose response was not different between exercise intensities (P>.05). Twenty-four-hour AUC was not affected by exercise intensity (P=.75). There was a significant effect for exercise enjoyment (P=.02), with LIE (69±4) preferred less than HIIE (mean±SD: 84±14; P=.02), MIE (73±5; P=.03), and no-exercise (75±4; P=.03). Exercise at any intensity 30minutes after a meal affects glycemic regulation equally in insufficiently active males. Moderate to vigorous exercise intensities were preferred, and therefore, the exercise guidelines appear appropriate for the prevention of cardiometabolic disease.