Objective: Verify through a systematic revision the importance of the hydration in sports practice. Hydration is a primordial and great important component as in the professional athletic preparation as in an unprofessional sportsperson, although, not always receive from those the necessary care and a mistake in its handling can cause serious consequences in terms of performance and general health. Understands the physiology of hydration mechanisms of thermoregulation of the body and its response to stress situations as hyponatremia, muscles cramps, heat collapse and also has direct relation with the variables heart rate, lactate concentration, urine specific gravity and subjective perception of the effort. Methodology: The review was condu...