Energy compensation after an aerobic exercise session in high-fat/low-fit and low-fat/high-fit young male subjects.

There is general agreement that exercise-induced energy expenditure is not entirely compensated for at the next meal or over the following 24 h, but inter-individual variability is high. The role of ‘fatness and fitness’ in this variability has never been assessed. Therefore, eighteen non-obese male subjects aged 22·2 (sd 2·0) years were selected and separated into a ‘high-fatness and low-fitness’ (Hfat/Lfit, n 9) and a ‘low-fatness and high-fitness’ (Lfat/Hfit, n 9) group, according to three criteria: maximal oxygen uptake; weekly hours of physical activity; fat mass index. At 1 h before lunch, they were subjected to 60 min of exercise on a cycle ergometer (70 % VO2max), or stayed at rest. Then, they self-reported food intake in diaries until the next breakfast. Intake at lunch was not different between conditions, but was higher after exercise than after rest over the 24 h, leading to a significant but partial mean level of compensation of 49·8 (sem 16·5) and 37·8 (sem 24·6) % for the Hfat/Lfit and Lfat/Hfit groups, respectively. Energy compensation at lunch and over the 24 h were strongly correlated (r 0·76, P< 0·001). Both groups consumed more fat and protein after exercise than after rest over the 24 h, but the percentage of energy derived from fat increased only in the Hfat/Lfit group (2·1 (sem 0·6) %, P= 0·026). Thus, the energy cost of an aerobic exercise session was partially compensated over the next 24 h independently of the ‘fatness and fitness’ status, but ‘high-fat and low-fit’ individuals compensated more specifically on fats.