Ad libitum fluid intake does not prevent dehydration in suboptimally hydrated young soccer players during a training session of a summer camp.

UNLABELLED: There is a lack of studies concerning hydration status of young athletes exercising in the heat. PURPOSE: To assess preexercise hydration status in young soccer players during a summer sports camp and to evaluate body- water balance after soccer training sessions. METHODS: Initial hydration status was assessed in 107 young male soccer players (age 11-16 yr) during the 2nd day of the camp. Seventy-two athletes agreed to be monitored during 2 more training sessions (3rd and 5th days of the camp) to calculate dehydration via changes in body weight, while water drinking was allowed ad libitum. Hydration status was assessed via urine specific gravity (USG), urine color, and changes in total body weight. Mean environmental temperature and humidity were 27.2 ± 2 °C and 57% ± 9%, respectively. RESULTS: According to USG values, 95 of 107 of the players were hypohydrated (USG ≥ 1.020) before practice. The prevalence of dehydration observed was maintained on both days, with 95.8% and 97.2% of the players being dehydrated after the training sessions on the 3rd and 5th days, respectively. Despite fluid availability, 54 of the 66 (81.8%) dehydrated players reduced their body weight (-0.35 ± 0.04 kg) as a response to training, while 74.6% (47 out of the 63) further reduced their body weight (-0.22 ± 0.03 kg) after training on the 5th day. CONCLUSION: Approximately 90% of the young soccer players who began exercising under warm weather conditions were hypohydrated, while drinking ad libitum during practice did not prevent further dehydration in already dehydrated players.

The anthropometrical and physiological characteristics of elite water polo players.

In order to examine the physical and physiological demands of water polo, we assessed the profile of elite water polo players. Nineteen male professional water polo players (age: 25.5+/-5.0 years, height: 184.5+/-4.3 cm body mass: 90.7+/-6.4 kg) underwent body composition assessment by dual-energy X-ray absorptiometry. We also evaluated peak oxygen consumption VO2peak, lactate threshold (LT), energy cost of swimming (C s), anaerobic capacity and isokinetic shoulder strength. Body fat (%) was 16.8+/-4.4, lean mass (LM) 75.1+/-4.9 kg and bone mineral density (BMD) 1.37+/-0.07 g.cm(-2) . VO2peak was 57.9+/-7 ml.kg(-1). min(-1) . LT was identified at 3.9+/-0.7 mmol.l(-1) at a swimming velocity (v) of 1.33+/-0.05 m.s(-1) with a heart rate of 154+/-7 bpm, corresponding to an intensity of 83+/-9 of VO2peak. The average C s of swimming at the LT was 1.08+/-0.04 kJ.m(-1).C s at LT was correlated to body mass index (BMI) (r=0.22, P=0.04) and to swimming performance at 400 m (r=0.86, P=0.01) and 4 x 50 m (r=0.84, P<0.01). Internal rotator muscles were stronger compared to the external rotators by a 2:1 ratio. This study provides a quantitative representation of both physical and physiological demands of water polo and proposes a comprehensive battery of tests that can be used for assessing the status of a team.