Effects Of Dehydration On Anaerobic Performance In Adolescent Judo Athletes

Many young athletes that participate in weight-class sports dehydrate in the hours preceding a competition in order to “make weight”. The effects of dehydration induced by exercise and insufficient drinking on anaerobic power in adolescent judo athletes is not known. PURPOSE To determine the effects of dehydration on leg muscle power, endurance and fatigability of heat acclimatized adolescent judo athletes. METHODS Ten athletes (x age = 15.3±0.3) performed the 30 s Wingate Anaerobic Test prior to (PRE) and 45 minutes after (POST) the end of a training session in a non-air conditioned gymnasium (29.7 °C and 77.4% RH) in two different hydration conditions. In one condition they drank water voluntarily (VD) when fluid breaks were allowed by the coach. In a control session, they were provided a sports drink periodically to replace sweat losses (FD). The duration of the training session was of 101.8±1.1 min. RESULTS At the end of the VD session subjects had lost 1.3±0.1 kg corresponding to 2.3±0.1% of the pre-training body weight due to insufficient drinking. Estimated fluid intake (123.0±43.3 mL) replaced only 9% of the sweat loss (1,379.5±87.5 mL). In the FD session initial body weight was maintained. A significant decrease (P < 0.05) was observed in peak (PP) and mean (MP) power in VD (PP: PRE = 577.0±28.8; POST = 542.5±32.9 W; MP: PRE = 442±21.8; POST = 418.5±24.9 W) and FD (PP: PRE = 608.1±35.7; POST = 575.3±30.9 W; MP: PRE = 445±20.2; POST = 423.6±20.4 W). The decrease was not different (P > 0.05) among conditions (VD [PP:34.5±14.4 W; MP = 23.8±6.4 W] and FD [PP = 32.8±10.7 W; MP = 21.9±7.9 W). The fatigue index was similar PRE vs POST in both conditions. During the VD condition all the subjects reported feeling thirsty, three had a headache, two felt extremely fatigued and one felt nauseas. None of these symptoms were reported during FD. CONCLUSIONS The decrease in anaerobic power and endurance observed in adolescent judo athletes after a training session in hot and humid conditions cannot be attributed to dehydration alone. However, the negative symptoms of dehydration observed in these athletes may affect the quality of training and performance during competition.