Question

athletes often travels to high elevations, like Lake Tahoe in California, to train. The partial pressure of oxygen is often low at these high elevations. what would be the advantage of an athlete who lives and competes in wisconsin, to train in Lake Tahoe? you must answer this at a physiological level.

Answer 1

At high altitudes the air is thinner and there are fewer oxygen molecules per volume of air, as a result every breath taken at a high altitude delivers less of oxygen to the working muscles, this is the reason why initialy when you train at high altitudes you get very tired at faster rate as compared to lower altitude. As you continue training, your body starts adapting, to compensate for the the decreasing levels of oxygen it does by stimulating kidney to produce a hormone by name Erythropoietin (EPO), this hormone has a effect of producing more red blood cell, with increased red blood cells there is increased oxygen supply to working muscles, increasing oxygen means extra energy.

This EPO more or less works like performing enhancing drug. By training at high altitudes, athletes aim to allow their bodies to produce extra red blood cells and than when they take part at events at low altitudes they try to  take advantage of their changed physiology. This effect is not everlasting it may last for 10 to 15 days.