Altitude training, sometimes called an altitude camp, is a way of encouraging the body to produce more red blood cells, which can improve endurance when performing activities at lower altitudes. This kind of training ideally involves living at a high altitude and training at a lower one, because the body needs oxygen to train. While it is possible to simulate altitude training using specially modified houses and training facilities, it is more common to actually travel to high altitudes in order to train. Athletes from endurance sports typically benefit from this kind of training, but its effects will be felt by anyone who has an extended stay at a high altitude.
For the purposes of altitude training, an altitude of about 8,000 ft (2,500 m) is desirable, but any relatively high altitude will work. It can be difficult to find altitudes this high that are still fit for training, so it is common to use a lower altitude. For simulations of high altitudes, the pressure to which the athletes are exposed is not changed, but the amount of oxygen in the air is reduced. Typically, air contains around 20.9 percent oxygen at sea level, and an artificial altitude training apparatus will reduce this amount to around 15.3 percent.
The purpose of altitude training is to increase the number of red blood cells in the body. This is accomplished by harnessing the body’s natural response to needing more oxygen over an extended period of time. There are people who question whether altitude training actually works by increasing the number of red blood cells or if it is even effective at all. In theory, if one is competing at sea level, the increase in red blood cells will persist for several days after leaving the high altitude, giving one a competitive edge. It can be argued that any positive effects dissipate too quickly to be useful.
While altitude training is primarily used by athletes who need increased endurance, the desired effects of high altitudes will be experienced by anyone who travels to a high altitude for an extended period of time. Many people experience a notable increase in energy and vigor when returning from high altitudes. Children who normally live at high altitudes can become very hyperactive when brought to low altitudes due to similar effects. It is clear, then, that the effects of altitude training can be verified, although the exact mechanism and potential for use may be up for debate.