Depletion of the body's carbohydrates stores and dehydration are two factors that will limit prolonged exercise.
Sweating is the way in which the body maintains its core temperature at 37 degrees centigrade. This results in the loss of body fluid and electrolytes (minerals such as chloride, calcium, magnesium, sodium and potassium) and if unchecked will lead to dehydration and eventually circulatory collapse and heat stroke. The effect of fluid loss on the body is as follows:
- 2%: Impaired performance
- 4%: Capacity for muscular work declines
- 5%: Heat exhaustion
- 7%: Hallucinations
- 10%: Circulatory collapse and heat stroke