Performing at altitude

VO2max is the body's maximal ability to extract oxygen from the air and deliver it to the tissues. Above 5000 feet the maximum work a person can do decreases by 3% for every 1,000 feet. This means your body's ability to utilize oxygen diminishes with increasing altitude. Even after acclimatization, this only improves a little bit and a person can never perform as well at altitude as they can at sea level. With increasing altitude, you need to take more air into your lungs, contributing to the breathless feeling that many athletes experience when first coming to altitude, and especially if trying to perform at the same intensity as at sea level. One of the processes in acclimatization important for athletes is the production of a hormone called EPO or erythropoietin. This hormone acts on the bone marrow to produce more red blood cells. These cells carry oxygen from the lungs to the tissues. Increasing these cells effectively increases the 'oxygen carrying capacity' in your blood. However, this process takes weeks. EPO is a big topic among competitive endurance athletes.

For those athletes doing aerobic events over 5000 feet, 10-20 days of acclimatization at the performing altitude is ideal. Athletes participating in events over 12,000 feet must have acclimatization at an intermediate altitude prior to performance. Performing without acclimatization at this altitude could cause altitude sickness. Those participating in anaerobic sports (short intense events lasting less than 2 minutes, such as sprinting) at altitude do not require extended acclimatization, and may perform better because of lower air density.