To analyze the effect of body composition changes, from a period of weight maintenance to before a competition, on forearm maximal strength in male judo athletes. METHODS: A total of 26 men, top-level athletes (age: 23.2±2.9 yrs), were evaluated at baseline [weight. 73.1±7.1 kg; percent fat mass (%FM): 12.2±3.1 %] and 1-2 days before a competition (Weight: 72.0±7.0 kg; %FM: 11.7±2.8 %), with approximately 1 month apart between moments. Before the competition some of these athletes lost weight through self-determined means while others remained or increased their weight. A 7-day recall of dietary food intake was recorded at baseline and before the competition. At both moments, and after an overnight fasting, total body water (TBW), extracellular (ECW), and intracellular water (ICW) were estimated by bioelectrical impedance spectroscopy while FM, fat-free mass (FFM), lean soft tissue (LST), and arms LST were assessed by dual-energy x-ray absoptiometry (DXA). At baseline and at before a competition, a handgrip was used to assess forearm maximal strength (FMS) of the dominant arm. Changes are expressed as a percentage of the baseline value; comparisons of means, bivariate and partial correlations were used. RESULTS: A significant mean reduction (p<0.05) in weight [-1.4±2.4 %, -6.2 to 2.8 % (mean ± SD, range)] and FM (-4.6±9.6 %, -21.9 to 14.0 %) was observed while no significant mean changes were found in FFM (-0.9±2.3 %, -5.4 to 3.1 %), LST (-0.9±2.4 %, -5.8 to 3.2 %), arms LST (-1.7±4.4 %, -9.9 to 4.2 %), TBW (-0.6±3.7 %, -9.2 to 5.9 %), ECW (-0.8±4.8 %, -15.8 to 5.9 %), ICW (-0.4±5.4 %, -10.9 to 8.6 %), energy intake (-6.2±27.9 %, -54.1 to 54.9 %), and FMS (0.7±7.5 %, -16.3 to 18.6 %). From all the above variations in body composition variables, changes in FMS were only significantly related with changes in ICW (r=0.559, p=0.003) but not with changes in TBW (r=0.338, p=0.091); the significant association of ICW and FMS alterations remained after controlling for weight and arms LST changes (r=0.558, p=0.005) which means that those athletes that lost water from the intracellular compartment were those that reduced forearm maximal strength, even after adjusting for the potential effect of variations in weight and arms LST observed before a competition. CONCLUSION: These findings highlight the need of assessing and tracking total-body water, specifically the intracellular water compartment, in elite Judo athletes to avoid reductions in grip strength when a target body weight is desired before a competition.
© Copyright 2009 14th annual Congress of the European College of Sport Science, Oslo/Norway, June 24-27, 2009, Book of Abstracts. Published by The Norwegian School of Sport Sciences. All rights reserved.