exercise in the heat

Question 1

thermoregulation

Answer 1

the body’s ability to maintain its core temperature between 36-38 degrees Celsius

Question 2

thermoceptors

Answer 2

located all around the body + detect a change in core temperature

Question 3

thermoregulatory centre

Answer 3

Medulla

Question 4

evaporation

Answer 4

heat lost by liquid/ sweating

Question 5

vasodilation

Answer 5

blood vessel widens = heat conducts off

Question 6

warm environments

Answer 6

• vasodilation = blood vessels dilate (widen) moving it closer to the skin, increases the amount of heat lost through convection (gases) + evaporation (liquid/vapour) = release heat
• Sweating (cardiovascular drift) = essential to lose heat, can lead to loss of 2-3l of fluid, less to dehydration = must drink enough water to replace water lost
• Remove outer layers of clothes = more skin exposed, more evaporation/ convection to take place to the air rather than on clothes

Question 7

Cardiovascular drift

Answer 7

• During exercise, we lose water/ blood plasma from blood in order to sweat (20 mins)
• Makes blood more viscous
• Blood is now harder to pump around the body
• The heart starts to work harder, so increase in HR (decrease in SV = not enough oxygenated blood to pump because blood becomes thicker, not enough plasma = watery)
• can lead to us being light-heated, reach OBLA quicker

= Falls during aerobic activity = constantly working out body, steady state

Question 8

strategies for hot environment

Answer 8

• acclimatisation - 7-14 days before event (e.g. trams before a World Cup)
• Hydration - before, during and after
• Clothing - breathable, dri-fit, lightweight
• Cooling aids - ice vests jackets/ ice baths

Question 9

cold environement

Answer 9

• hairs stand on end = trap a layer of hot air within the hairs, help warm up the surface of the body, only minimal amounts of heat
• Vasoconstriction = blood vessels constrict + move away from the surface of the skin, bringing them closer to the core of the body to maintain temp, reduces heat loss as heat cannot easily pass through the skin while vessels are constricted
• Shivering = involves lots of little contractions, each muscle contraction generates heat that can be used to warm up the body’s core