Relative losses of water and electrolytes lead to hypo-, iso- or hyper-osmotic hypohydration.
Additionally, carbohydrate, protein, and water play a fundamental role in recovery processes, with poor recovery nutrition being linked to reduced glycogen and tissue protein synthesis, hypohydration, and immunodepression [8, 9, 43, 53, 55, 56].
The decline in aerobic performance that occurs with hypohydration has largely been attributed to circulatory strain, whereby reductions in blood volume limit oxygen transport to the exercising muscle [78, 79].
The impact of exercise on learning and memory is also sensitive to hydration status, so we hypothesized that mild hypohydration induced with exercise, will adversely impact executive and complex memory function tasks and that these changes in cognitive function are independent of changes in emotion.
There is a paucity of data regarding the effect of hypohydration on tennis-specific performance.
Increased serum cortisol has already been associated with hypohydration in strenuous conditions, and the present findings support this observation.
However, hypohydration has been found to impair aerobic performance, postural balance, 55 cognitive performance, mood and mental readiness, 56 57 which are all important components of tennis performance.
Moreover, in some instances of hypohydration, plasma and serum osmolality do not track closely with acute changes in body weight or urinary indices.
Thus, it is important to note that the detrimental effect of hypohydration on aerobic performance is exacerbated when combined with heat stress.
Pretest data indicated euhydration in 6 athletes, however in 2 athletes signs of mild hypohydration were detected, what possibly influenced the results.
56 Furthermore, hypohydration impairs the body's heat dissipating mechanisms (ie, skin blood flow and sweating), leading to increased core temperature and risk of heat illness.
