PHYS30005 Lecture Notes - Lecture 11: Vo2 Max, Cardiac Output, Fluid Compartments
25 Jul 2018
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Document Summary
Lecture 11 temperature and fluid balance during exercise. The major mechanism of heat loss during exercise in a warm environment is evaporation of sweat (conduction when cold, convection if in water/wind) Measure oesophageal or rectal temperature (rectal higher than core if a lot of lower limb movement near major vessels) Generate heat right from start but takes some time for metabolic heat loss mechanisms to kick in. Therefore time period where rate of heat production > rate of heat loss but eventually reaches equilibrium. Metabolic heat production is proportional to power output and o2 consumption. Rate of sweating is proportional to vo2 max (body has better thermoregulatory mechanisms) Electrolytes and osmolarity of sweat plasma and muscle. Control of sweating during exercise: sympathetic cholinergic nerves, core temperature (metabolic heat production, skin temperature, dehydration and associated plasma hyperosmolarity and hypovolemia, reduce sweat. Increased sweat gland recruitment and increased sweat released per gland rate and sensitivity and increase sweating threshold.
