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

© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd 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 ± 7.3 years, BMI: 29.3 ± 6.5 kg·m−2) completed four 30-minute interventions at weekly intervals comprising low-intensity exercise (LIE) at ~35% VO2R, moderate-intensity exercise (MIE) at ~50% VO2R, high-intensity interval exercise (HIIE) at ~80% VO2R, and a no-exercise control. Participants performed cycle ergometer exercise 30 minutes 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 ± 148 kJ) and HIIE (806 ± 145 kJ), which were both greater than LIE (633 ± 129 kJ). The pattern of glucose response between the interventions over time was different (P =.02). Glucose was lower 25 minutes into each of the HIIE, MIE and LIE trials respectively (mean difference ± SD: −0.7 ± 1.1; −0.9 ± 1.1; −0.6 ± 0.9 mmol·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 30 minutes 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.