Environmental Impacts Flashcards
Human thermoregulation
- resting body temp maintained at 37+- degrees
-
dual thermic properties
- core temp: regulated by brain
- skin temp: is influnced more by skin blood flow and environment
- tsk is slave to Tc for thermal balance
regulation of temp (brain)
the hypothalamus contains the central coordinating centre or temp regulation:
1- thermal receptors in the skin provide input to the control centre
2- changes in the blood tempreture directly prefuse and stimulate the hypothalamus
heat transfer ways
Heat transfer occurs:
- radiation
- conduction
- convection
- evaportation
what happens when you exercise in the heat
circultatory adjustments:
- competition for CV output (muscle, periphery)
- The body tries to maintain CO when PV is reduced at the expense of peripheral BF
In submaximal exercise:
- similar CO, decreased PV and SV, increased HR
- compensatory HR effect in maximal exercise cannot off set the SV decrease so CO is reduced
cardiovascular drift
- exercising in the heat
- increase in HR over time, to compensate for the decreased SV allowing for maintence of CO
Acclimatisation defintion
the process or result of becoming accustomed to a new climate or to new conditions
- 7-14 days exposure
- 90mins a day
Adaptive respones to acclimatisation (sweat, temp and CV)
sweat responses: - increased sweat rate - decreased sweat threshold - decreased sweat concentration of Na and Cl Tempreture response: - decreased Tc and Tsk Cardiovascular responses: - increased plasma volume - decreased heart rate - decreased vasodilation threshold
Methods to help with heat
- pre cooling
- ice vests
- ice slushys
- fans/mist
- cold/ice baths
fluid loss during exercise is determined by
- intensity and duration of exercise
- environmental conditions
- clothing worn
- metabolic rate
in reponse the body sweats and evaopration of sweat releases heat
define dehydration and explain effects
the loss of fluids and salts essential to maintain normal body function
- muscle fatigue
- loss of coordination
- inability to regulate body temp
- heat illness
- reduced performance
what should i drink
- CHO in sports drink to help maintain glucose or replenish glycogen stores
- electrolyes may also help to maintain glucose or replenish glycogen stores
- drink 1300-1560ml of water for every 1kg lost withing 2 hours of exercise
hypoantremia
- drinking too much
- excess of sodium losses in sweat
- over consumption of water
- reduced blood sodium levels causes the body to think there is too much sodium in the body which transfers water into the cells causes thing to swell
checking hydration status equation
pre exercise body mass - post exercise body mass * 100 divided by pre exercise body mass
partial pressure and 02 diffusion in the environment
at altitude:
- atmospheric pressure changes
- alters saturation of Hb
