Page 96 - Athletic Health Handbook
P. 96
Effects of Dehydration Upon dehydration compromises sweat rate will be lost during exercise. Exercise
Exercise Performance and blood flow to the skin. In these in hot, humid environments will
situations the athlete’s ability to exer- require more liquid intake to main-
Endurance cise may be severely compromised. tain fluid balance and performance.
Furthermore, gastric emptying rates,
Both hypohydration and a water Strength and therefore tolerance, may vary
deficit produced during exercise can The effects of hypohydration upon considerably among individuals.
impair performance. Hypohydration strength are not as clearly docu- Athletes should always experiment
produced prior to exercise by such mented. Athletes who compete during practice, varying the amount
methods as fluid restriction or according to weight class, such as and type of beverage to determine
diuretic use profoundly hinders boxers or wrestlers often “make what is best tolerated.
endurance by decreasing plasma weight” using a combination of fluid
volume. Most athletes do not volun- restriction, sweating, and diuretics. Pre-hydration
tarily consume enough fluid during These athletes will often attempt
exercise to offset the fluid lost via rapid rehydration during the period Two hours prior to exercise the
sweating, making some degree of time between weigh-in and athlete should consume two cups of
of dehydration probable during competition. Muscle strength and fluid. While water and sports drinks
prolonged exercise. Aerobic perform- anaerobic performance may be are easily absorbed, the individual
ance may be affected with even decreased after rapid weight loss and may also opt for any other non-
moderate degrees of fluid deficit. recovery of strength often requires caffeinated, non-alcoholic beverage.
A loss of body weight of as little at five to 24 hours of rehydration. Half an hour prior to exercise
as 2 percent, due to exercise sweat Athletes should not attempt a weight another one cup of either a sports
losses, has been shown to decrease reduction of more than 4 percent drink or water should be ingested.
maximal time to exhaustion. Skill of body weight, especially if time for To speed absorption the sports drink
performance may also be negatively rehydration is less than five hours. should not contain more than 6 to
affected by inadequate replacement 8 percent carbohydrate. Fruit juice
of fluids during exercise. The effect Fluid Guidelines should be avoided just before and
upon exercise performance is most during exercise since it contains
profound when dehydration is The amount of fluid required is fructose, a sugar known to increase
compounded by heat stress, since dependent upon how much sweat complaints of gastro-intestinal upset.

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