The imbalance between fluid intake and sweating during sports activities can lead the individual to hypohydration, causing damage to health and physical performance. The aim of this study was to evaluate the hydration status of football players in the sub-15 category of a Serie A club in Brazil. Nine under-15 athletes (64.9 ± 8.6 kg, 171.3 ± 8.3 and BF= 9.3 ± 1.6%) were evaluated in three collective training sessions (T1, T2 and T3). The athletes' body mass was measured before and after training. Fluid intake and training time were recorded by the researchers. From this information, the sweating rate (SR), total fluid intake (TIL), dehydration (% weight loss) and fluids replacement rate (FRR) were calculated. The distance covered by t...