Discover How To Get Rid Of Excess Body Heat
CHAPTER
10
EXERCISE IN HOT AND COLD ENVIRONMENTS: THERMOREGULATION
Learning Objectives
Find out how the body gets rid of excess body heat to maintain homeostasis at rest and during exercise. Discover how the body adapts to exercise in a hot environment. Learn why humidity, wind, and cloud cover are important factors when exercising in the heat. Differentiate heat cramps from heat exhaustion from heat stroke.
(continued)
1
Learning Objectives
Learn how the body minimizes excessive heat loss during exposure to cold. Find out the dangers of cold-water immersion. Discover how to exercise safely in the cold.
BODY HEAT GAINED AND LOST
2
Modes of Heat Transfer
Conduction—direct molecular contact with an object Convection—motion …show more content…
Peripheral thermoreceptors in the skin relay information back to the hypothalamus. Central thermoreceptors in the hypothalamus transmit information about internal body temperature. Sweat gland activity increases to lower body temperature by evaporative heat loss.
(continued)
Key Points
Control of Heat Exchange
Smooth muscles in the arterioles dilate or constrict to allow the blood to dissipate or retain heat. Skeletal muscle activity increases temperature by increasing metabolic heat. Metabolic heat production can also be increased by actions of hormones.
9
Cardiovascular Response to Exercise in the Heat
Active muscles and skin compete for blood supply. Stroke volume decreases. Heart rate gradually increases to compensate for lower SV (cardiovascular drift).
Metabolic Responses to Exercise in the …show more content…
You can achieve heat acclimatization by exercising in the heat for 1 hour or more each day for 5 to 10 days. Cardiovascular adaptations occur within the first 3 to 5 days while changes in sweating mechanisms may take up to 10 days. Reduce exercise intensity to 60% to 70% the first few days before resuming more intense workouts.
15
Key Points
Heat Acclimatization
Repeated exposure to heat stress during exercise improves your ability to get rid of excess heat. Sweating starts earlier and increases in well-exposed areas to promote heat loss. Core temperature and HR decrease while SV increases to aid in delivery of more blood to the muscles and skin. Muscle glycogen use is reduced to delay onset of fatigue. Amount of heat acclimatization depends on environmental conditions and duration of exposure and intensity of
10
EXERCISE IN HOT AND COLD ENVIRONMENTS: THERMOREGULATION
Learning Objectives
Find out how the body gets rid of excess body heat to maintain homeostasis at rest and during exercise. Discover how the body adapts to exercise in a hot environment. Learn why humidity, wind, and cloud cover are important factors when exercising in the heat. Differentiate heat cramps from heat exhaustion from heat stroke.
(continued)
1
Learning Objectives
Learn how the body minimizes excessive heat loss during exposure to cold. Find out the dangers of cold-water immersion. Discover how to exercise safely in the cold.
BODY HEAT GAINED AND LOST
2
Modes of Heat Transfer
Conduction—direct molecular contact with an object Convection—motion …show more content…
Peripheral thermoreceptors in the skin relay information back to the hypothalamus. Central thermoreceptors in the hypothalamus transmit information about internal body temperature. Sweat gland activity increases to lower body temperature by evaporative heat loss.
(continued)
Key Points
Control of Heat Exchange
Smooth muscles in the arterioles dilate or constrict to allow the blood to dissipate or retain heat. Skeletal muscle activity increases temperature by increasing metabolic heat. Metabolic heat production can also be increased by actions of hormones.
9
Cardiovascular Response to Exercise in the Heat
Active muscles and skin compete for blood supply. Stroke volume decreases. Heart rate gradually increases to compensate for lower SV (cardiovascular drift).
Metabolic Responses to Exercise in the …show more content…
You can achieve heat acclimatization by exercising in the heat for 1 hour or more each day for 5 to 10 days. Cardiovascular adaptations occur within the first 3 to 5 days while changes in sweating mechanisms may take up to 10 days. Reduce exercise intensity to 60% to 70% the first few days before resuming more intense workouts.
15
Key Points
Heat Acclimatization
Repeated exposure to heat stress during exercise improves your ability to get rid of excess heat. Sweating starts earlier and increases in well-exposed areas to promote heat loss. Core temperature and HR decrease while SV increases to aid in delivery of more blood to the muscles and skin. Muscle glycogen use is reduced to delay onset of fatigue. Amount of heat acclimatization depends on environmental conditions and duration of exposure and intensity of