Thermoregulation in exercise

Heat produced by muscle, ways of losing it, sweating, heatstroke and acclimatisation.

The outline, topic by topic

Each topic is weighted the way the exam weighs it.

Muscle efficiency: what is it?
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Only 20 to 25 % of energy becomes work; the rest becomes heat.
Exercise therefore heats the body strongly.
Running at 30 °C in saturated humid air, sweat drips without cooling. Why?
- Sweat no longer evaporates, so it removes no heat
- Sweat is too salty
- The heart slows
- Humid air blocks convection
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Sweat no longer evaporates, so it removes no heat
Only evaporating sweat cools.
Evaporation: what is it?
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Heat loss as sweat evaporates from the skin.
It is the main route in exercise, especially in heat.
Why must heatstroke be cooled before any transport?
- Only to lower heart rate
- Every minute above 40 °C damages organs
- So that sweating restarts by itself
- To prevent dehydration
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Every minute above 40 °C damages organs
The outcome depends on how long the hyperthermia lasts.