Abstract
The rate of metabolic heat production during prolonged exercise maybe increased to
15-20 times that at rest. Evaporation of sweat secreted onto the skin can effectively
limit the rise in body temperature which would otherwise occur, but results in the
loss of water and electrolytes from the body. Dehydration and an increased thermal
load can accelerate the onset of fatigue during exercise. The available evidence supports
the idea that ingestion of fluids during prolonged exercise can improve performance.
Heart rate and rectal temperature will generally be lower, and plasma volume will
be better maintained when fluids are given. There is, however, no general agreement
on the optimum formulation nor on the frequency or volume of drinking that is mosv
appropriate. In practice, the ideal solution will depend on a number of factors, including
the duration and intensity of the exercise, the environmental conditions and the characteristics
of the individual. The variation between individuals is, however, large and the optimum
strategy can only be established by subjective experience.
Key words
Sweating - fluid balance - dehydration - fatigue
