Impact of energy restriction with or without resistance training on energy metabolism in overweight and obese postmenopausal women

Objective The present study measured the impact of adding resistance training to an energy-restricted diet on the components of energy expenditure in overweight or obese postmenopausal women. Methods Participants (n = 137) were randomly divided into two groups: (1) a diet and resistance training (DRT) group and (2) a diet-only (DO) group. Women followed a 6-month energy-restricted diet consisting of 2,100 to 3,360 kJ less than daily needs. The DRT group also followed a resistance training program (three times a week). Resting energy expenditure (REE) was measured by indirect calorimetry. Total energy expenditure was measured with doubly labeled water. Body composition was measured by dual-energy x-ray absorptiometry. Results Eighty nine women were included in the analyses for this study (DRT, n = 21; DO, n = 68). REE in both groups was significantly lower after the intervention (mean difference ± SD: DO, −0.26 ± 0.4 MJ d−1; DRT, −0.33 ± 0.4 MJ d−1; P ≤ 0.05). Relative REE, expressed per kilogram of lean body mass0.856 corrected for fat mass change, remained stable in both groups. Physical activity energy expenditure remained stable in both groups (mean difference ± SD: DO, 0.02 ± 1 MJ d−1, P = 0.91; DRT, −0.14 ± 1 MJ d−1, P = 0.64). Conclusions Adding resistance training to an energy-restricted diet does not significantly alter any compartment of energy expenditure. REE is lower owing to reduction in body composition compartments, but relative REE is not significantly altered.