title: Effect of two different weight-loss rates on body composition and strength and power-related performance in elite athletes.
abstract: When weight loss (WL) is necessary, athletes are advised to accomplish it gradually, at a rate of 0.5-1 kg/wk. However, it is possible that losing 0.5 kg/wk is better than 1 kg/wk in terms of preserving lean body mass (LBM) and performance. The aim of this study was to compare changes in body composition, strength, and power during a weekly body-weight (BW) loss of 0.7% slow reduction (SR) vs. 1.4% fast reduction (FR). We hypothesized that the faster WL regimen would result in more detrimental effects on both LBM and strength-related performance. Twenty-four athletes were randomized to SR (n = 13, 24 ± 3 yr, 71.9 ± 12.7 kg) or FR (n = 11, 22 ± 5 yr, 74.8 ± 11.7 kg). They followed energy-restricted diets promoting the predetermined weekly WL. All athletes included 4 resistance-training sessions/wk in their usual training regimen. The mean times spent in intervention for SR and FR were 8.5 ± 2.2 and 5.3 ± 0.9 wk, respectively (p < .001). BW, body composition (DEXA), 1-repetition-maximum (1RM) tests, 40-m sprint, and countermovement jump were measured before and after intervention. Energy intake was reduced by 19% ± 2% and 30% ± 4% in SR and FR, respectively (p = .003). BW and fat mass decreased in both SR and FR by 5.6% ± 0.8% and 5.5% ± 0.7% (0.7% ± 0.8% vs. 1.0% ± 0.4%/wk) and 31% ± 3% and 21 ± 4%, respectively. LBM increased in SR by 2.1% ± 0.4% (p < .001), whereas it was unchanged in FR (-0.2% ± 0.7%), with significant differences between groups (p < .01). In conclusion, data from this study suggest that athletes who want to gain LBM and increase 1RM strength during a WL period combined with strength training should aim for a weekly BW loss of 0.7%.
authors.affiliation: Norwegian School of Sport Sciences, Oslo, Norway.
authors.forename: Ina
authors.initials: I
authors.lastname: Garthe
authors.forename: Truls
authors.initials: T
authors.lastname: Raastad
authors.forename: Per Egil
authors.initials: PE
authors.lastname: Refsnes
authors.forename: Anu
authors.initials: A
authors.lastname: Koivisto
authors.forename: Jorunn
authors.initials: J
authors.lastname: Sundgot-Borgen
mesh_terms: D000293:Adolescent; D000328:Adult; D054874:Athletic Performance; D001823:Body Composition / Q000502:physiology*; D004038:Diet, Reducing / Q000009:adverse effects; D005260:Female; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000254:growth & development / Q000502:physiology*; D055070:Resistance Training; D015431:Weight Loss / Q000502:physiology*; D055815:Young Adult