Increased intensity of a single exercise bout stimulates subsequent fat intake

BACKGROUND: The physical activity pattern in society has in recent years ch anged from necessary occupational activity to voluntary activities during l eisure-time. How this change in lifestyle affects the selection of dietary intakes is presently unknown. OBJECTIVES: The aim of the present study was to investigate the different e ffects of high vs low-intensity exercise on the following day's dietary ene rgy intake and macronutrient selection. DESIGN: The study was designed as a controlled randomized cross-over study which compared food selection and energy intake the day following a low-int ensity vs a high-intensity exercise bout, We included 32 healthy normal-wei ght subjects of four subgroups (young males, young females, old males and o ld females). On two different occasions they performed either 60 min low-in tensity (30% of VOmax2) or 30 min high-intensity (60% of VOmax2) exercise d uring 24 h measurements of energy expenditure. The energy intake and macron utrient selection of the subsequent day was assessed by offering them an ad libitum buffet at breakfast and at lunch, RESULTS: Following the low-intensity exercise the subjects chose a diet wit h an energy percentage from fat similar to that of their habitual diet- 36. 7% (95% CI: 34.3, 39.0) vs 35.6% (95% CI: 33.0, 38.2; NS), Following the hi gh-intensity exercise they chose a diet with 39.9% (95% CI: 37.2, 42.6) fat , which was 3.2% (95% CI: 0.6, 5.9) higher than following the low-intensity exercise (P < 0.05) and 4.2% (95% CI: 1.1, 7.4) more than their habitual d iet (P < 0.01). CONCLUSIONS: The present study shows that changing the type of activity of a single exercise bout from 30% of maximal aerobic capacity for 60 min to 6 0% for only 30 min resulted in consumption of a diet the following day with a higher fat energy percentage compared with the diet selected after the l ow-intensity exercise. However, the higher fat content diet did not result in a higher energy intake.