Altitude training is used by many athletes hoping to have a competitive edge during athletic competitions. While it is advantageous to train at altitude for competitions held at high altitude, it appears to have little effect on improved performance at sea level. To make an informed decision regarding high altitude training, understand the advantages and disadvantages associated with it.
High and Hypoxic
According to the World of Sports Science, "high altitude" is the description given to any locale where you begin to experience the limitations that a reduced oxygen intake due to altitude places on your body. Elevations 6,500 feet and above are considered high altitude because of the large difference in oxygen content. High altitude locales are also called hypoxic environments -- "hypoxic" meaning "low oxygen."
It's In the Blood
Your body begins to adapt to high altitude almost immediately, and full acclimatization occurs within 15 to 20 days. When your body senses it is not receiving the amount of oxygen it is accustomed to, it begins to produce more red blood cells, which carry oxygen to your muscles. Your kidneys release a hormone called erythropoietin, which stimulates the production of red blood cells. The increased oxygen transportation from the red blood cells means your body will optimize the amount of available oxygen. The increase of red blood cells helps improve your VO2 max, which is the maximum amount of oxygen your body can obtain and use during intense exercise. However, VO2 max levels are lower at high altitude than at sea level.
Live High Train Low
While altitude training stimulates the production of red blood cells, it induces detraining effects due to an inability to train at the same intensities as at sea level. According to Sports Fitness Advisor, athletes training at 4000 feet can only train at 40 percent of their VO2 max at sea level. To offset the effects of detraining, some have experimented with the effects of a live high, train low model. A study by Levine and Stray-Gundersen published in the "Journal of Applied Physiology" found that by living at high altitude but training at sea level, athletes increased their VO2 max at sea level by five percent, which was in direct proportion to the increase in red cell mass volume. They also increased their running speed. However, for most athletes, living high and training low is not practical.
The Down Side of Training High
There are several disadvantages to training at high altitude. The stress of a hypoxic environment has been shown to have a negative effect on the immune system. It is also necessary to avoid overtraining at high altitude because of the stress it places on your body. One study reported in the "Journal of Sports Science and Medicine" found cross-country skiers had an increased amount of the stress hormone cortisol, which may indicate an overtraining state. Another problem with high altitude training is a loss of muscle mass because of the increase in metabolic rate.