Metabolic responses of a single bout of low-intensity exercise following mixed meals in healthy individuals

Exercise is a potent inducer of physiological changes at different levels, perturbing energy balance under different conditions. While high-intensity exercise is known to greatly stimulate central and peripheral signals, low doses of exercise are still controversially exploitable within a context of increasing global obesity. Here, we investigated postprandial responses (glucose, insulin, ghrelin, FFA) elicited by three diverse test-meal loads followed by a 20-min bout of low-intensity aerobic exercise. Nineteen healthy individuals (8M/11F; BMI 20.8±0.5 kg/m2; 31±0.7 yrs) completed 2 experimental trials (resting and exercise) in a randomised-crossover fashion. All subjects underwent a 50-g OGTT (A) and 3 test-meal loads: milk and cereals (B1); milk, apple and chocolate cream filled sponge cake (B2); milk, bread, apple and hazelnut chocolate cream (B3). In the exercise trial, participants cycled for 20 min at 40% VO2max, 100 minutes after load ingestion. A two-way repeated measures ANOVA was performed. No interaction between the type of oral test and physical activity was found. Exercise significantly decreased the final glucose concentration (p=0.004), and increased the final FFA concentration (p=0.002). These results have important implications for a society currently determined to offset excessive nutrient intake with increased physical activity.