Fat-free mass is maintained in women following a moderate diet and exercise program

Weight-loss programs usually result in fat-free mass (FFM) loss along with body-fat (BF) loss. This study examined which combination of diet + exercise would maintain FFM. Forty-four overweight, inactive women completed 20 wk of a randomized intervention: control (C, N = 6), diet only (D, N = 10), diet + cycling (DC, N = 8), diet + resistance training (DR, N = 11), or diet + resistance training + cycling (DRC, N = 9) group. FFM and %BF were determined from hydrostatic weighting. Exercise sessions were attended 3 d.wk-1, with a mean duration of 30 min per session. Caloric intake was reduced 628 kcal.d-1 (+/- 59). Chi squares and ANOVA showed no baseline differences between groups for socioeconomic status, age, body composition, aerobic capacity, or strength. One-way ANOVA of change with Student-Newman Keul multiple range post-hoc tests (P < 0.05) were used to analyze pre to post differences for %BF, body mass (BM), FFM, VO2max, and strength. D, DC, DR, and DRC lost significant BM (-3.7 to -5.4 kg) in comparison with C (+ 1.5 kg). All groups maintained FFM but only DRC significantly lowered %BF (-4.7%) in comparison with C. DRC and DC significantly increased VO2max. Strength 1RM (triceps extension, arm curl, leg extension, chest press) increased significantly for both DR and DRC. Results suggest that moderate levels of caloric restriction, aerobic cycle exercise, and/or resistance training are equally effective in maintaining FFM while encouraging body mass loss.