Abstract
There is evidence supporting that acute sprint interval training (SIT) might improve metabolic responses to postprandial glucose, but results are inconclusive. The aim of the present study was to explore the effects of acute SIT on metabolic response and substrate utilization in individuals with overweight/obesity after an oral 75-gram glucose challenge. Thirty-three participants with overweight/ obesity (32.7 ± 8.3 years, 24 male, 9 female) participated in the study and a crossover design was followed. After the 75-gram glucose load, participants were randomly allocated to two groups: no exercise (resting) or SIT protocol. Metabolic data including respiratory quotient (RQ) and substrate utilization rates (fats and carbohydrates) were collected using the COSMED Q-NRG + ® calorimeter. The RQ was significantly lower in the acute SIT group (0.76 [0.01]; p < 0.0001) than in the resting group (0.80 [0.01]; p = 0.036) at the 120-min postprandial time point, and the RQ area under the curve (AUC) was also lower in the SIT group (mean difference of -6.62, 95% CI -12.00 to -1.24; p = 0.0161). The contribution of fat to energy expenditure increased after SIT during the postprandial period whereas the contribution of carbohydrates decreased. The AUC for fat contribution was significantly higher (mean difference 2311.9, 95% confidence interval [CI] 578.8 to 4043.3; p = 0.0098) and the AUC for carbohydrate contribution was significantly lower (mean difference -2283.1, 95% CI -4040.2 to -527.1; p = 0.0117) in the SIT group than in the resting group. In conclusions, acute SIT might have a positive effect on metabolic responses to postprandial glucose and, accordingly, should be recommended for improving metabolism in people with overweight/obesity.