ABSTRACT
BACKGROUND: The compensatory effect of exercise on total volume of physical activity and food intake has been described as a possible explanation for the limited body weight loss observed during exercise interventions. OBJECTIVE: To investigate the effect of different exercise intensities on total volume of physical activity and energy intake amongst active men with overweight. DESIGN: Young men with overweight from a naval academy (n = 72; mean ± SD, age 21 ± 2 years, BMI 27.9 ± 2.13 kg/m2) were randomised to a control group (CG), moderate-intensity (MEG), or vigorous-intensity exercise group (VEG). MEG and VEG performed exercise sessions three times per week, for 60 min, during a 2-week period. Physical activity was assessed using triaxial accelerometers for 13 days. Energy intake was assessed at four time-points by 24-hour food recall. Intention-to-treat analyses were performed using linear mixed effect models. RESULTS: MEG and VEG presented a greater compensatory effect in the total volume of physical activity over time compared to CG, with a significant difference in the rate of change between VEG and CG (∆ = -250,503 counts vs. ∆ = -61,306 counts, respectively; p = 0.01), and MEG and CG (∆ = -253,336 counts vs. ∆ = -61,306 counts, respectively; p = 0.01). There was no difference between MEG and VEG (p = 0.97). Changes in energy intake were not different between groups (p = 0.18); however, MEG presented greater energy intake compared to CG (ß=491 kcal/day; p = 0.01) and VEG (ß=319 kcal/day; p = 0.07). VEG presented a greater reduction in body weight compared to MEG (-1.3 kg vs. -0.4 kg; p = 0.03) and CG (-1.3 kg vs. -0.6 kg; p = 0.07). CONCLUSIONS: Two weeks of exercise promoted a compensatory effect in total volume of physical activity in active men with overweight, regardless of exercise intensity. The compensatory effect was not observed for energy intake, although there was a trend for higher absolute energy intake in the MEG. Consequently, individuals in the VEG showed greater reduction in body weight over the intervention period.
Subject(s)
Exercise , Overweight , Adult , Body Weight , Energy Intake , Energy Metabolism , Humans , Male , Overweight/therapy , Young AdultABSTRACT
BACKGROUND/OBJECTIVES: Body composition (BC) does not always vary as a function of exercise induced energy expenditure (exercise EE - resting EE). Energy balance variables were measured to understand energy compensation (EC) in response to an exercise intervention performed at low (LOW) or moderate (MOD) intensity. SUBJECTS/METHODS: Twenty-one women with overweight/obesity (33 ± 5 kg/m2; 29 ± 10 yrs; 31 ± 4 ml O2/kg/min) were randomized to a 3-month LOW or MOD (40 or 60% of VÈ®2reserve, respectively) matched to expend 1500 kcal/week (compliance = 97 ± 5%). Body energy stores (DXA), energy intake (EI) (food menu and food diaries), resting EE (indirect calorimetry), total EE (doubly-labeled water), time spent in different activities (accelerometers), appetite (visual analog scale), eating behavior traits and food reward (liking and wanting) were assessed at baseline, after weeks 1 and 2 and at the end of the 3-month exercise intervention. RESULTS: EC based on BC changes (fat mass and fat-free mass) was 49 ± 79% and 161 ± 88% in LOW and MOD groups, respectively (p = 0.010). EI did not change significantly during the intervention. However, eating behavior traits and food reward had changed by the end of the 3-month supervised exercise. Non-structured physical activity (NSPA) decreased across the intervention (p < 0.002), independent of the intensity of the exercise training. CONCLUSION: Women with overweight/obesity training at LOW presented lower EC for a given energy cost of exercise. Our results strongly suggest that NSPA plays a major role in mediating the effects of exercise on energy balance and ultimately on changes in BC. CLINICAL TRIAL REGISTRATION: www.ClinicalTrials.gov, identifier ISRCTN31641049.
