Energy Compensation Following a Supervised Exercise Intervention in Women Living With Overweight/Obesity Is Accompanied by an Early and Sustained Decrease in Non-structured Physical Activity

Abstract

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 VȮ_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.

Keywords: body composition; doubly-labeled water; energy compensation; exercise intensity; non-structured physical activity; obesity.

FIGURE 1

Recruitment and sample size of the study.

FIGURE 2

Study design.

FIGURE 3

Changes in body weight and composition during the exercise intervention performed at LOW (n = 11) and MOD (n = 8). Variables were expressed as change scores. LOW group: Body weight = –1.0 ± 1.8; Fat mass = –0.9 ± 1.6; Fat-free mass = –0.1 ± 1.7. MOD group: Body weight = 1.2 ± 1.9; FM = 1.1 ± 1.9; Fat-free mass = 0.1 ± 2.7. ^∗, Indicates a significant main effect of group.

FIGURE 4

Components of total energy expenditure measured with indirect calorimetry and doubly-labeled water (REE, NSPA, exercise induced EE) [LOW (n = 11) and MOD (n = 10)]. TEF was not measured and fixed at 10% of total daily EE. ^∗NSPA, indicates a significant main effect of phase (p = 0.002, cohen’s f² = 0.299).