WK7- Exercise and the Environment

Question 1

How does altitude affect long term aerobic performance.

Answer 1

For exercise lasting more than two minutes the main limiting factor for performance at altitude is the lower partial pressure at height. Therefore performance will diminish.

Question 2

How does respiratory function change at altitude ?

Answer 2

Higher altitudes require higher ventilation rates due to the decreased amount of O2 available.

Question 3

What kind of physiological adaptions (acclimation) can people develop at high altitude and how does it work ?

Answer 3

Hypoxia inducible factor -1 (HIF-1) is normally produced in the body but is destroyed unless hypoxic conditions are experienced. In the event of hypoxia the kidneys take HIF-1 as a signal to produce more EPO which stimulates red blood cell genesis and nitric oxide synthase which promotes the creation of nitric oxide which is a powerful vessel dilator. More RBC’s counteract the effect of desaturated RBC’s due to lower PO2 at altitude.

Question 4

Explain the nuances of the live high train low method.

Answer 4

Live high train low refers to athletes who seek to reap the rewards of an increased number of red blood cells that come as an adaptation when one lives at high altitudes. responses differ between groups of people; generally elite athletes don’t reap the same rewards as someone who is simply trained. Baseline values of hemoglobin also matter, as generally, those who have lower Hb mass will see greater increase in Hb mass at altitude.

Question 5

List some of the common side effects, and treatments of heat related illnesses such as; exercise induced muscle cramps, heat syncope, heat exhaustion, extertional heat stroke.

Answer 5

cramps: visible cramping; rest, passive stretching, ice, massage, rehydrate
Heat Syncope: orthostatic dizziness due to dehydration, hypotension, venous pooling; brief episode of fainting associated with dizziness; move to shaded area, elevate legs above heart, cool skin, rehydrate
Heat Exhaustion: excessive fatigue, fainting, confusion, disorientation; move to shaded area, remove clothes, elevate legs, cool with ice towels, and fans, refer to physician
Heat stroke:high temp, disorientation, confusion, dizziness, hot sweaty skin; immediately cool the patient and remove clothing.