Altitude training Mechanism

An increase in red blood cell mass allows more oxygen to be supplied to the muscles allowing higher performance. Increases in red blood cell mass are stimulated by an increase in erythropoietin (EPO). The body naturally produces EPO to regulate red blood cell mass. Synthetic EPO also exists. Injections of synthetic EPO and blood doping are illegal in athletic competition because they cause an increase in red blood cells beyond the individual athlete's natural limits. This increase, unlike the increase caused by altitude training, can be dangerous to an athlete's health as the blood may become too thick and cause heart failure (see polycythemia). The natural secretion of EPO by the human kidneys can be increased by altitude training, but the body has limits on the amount of natural EPO that it will secrete, thus avoiding the harmful side effects of the illegal doping procedures.
Scientific studies[citation needed] have shown that altitude training can produce increases in speed, strength, endurance, and recovery. Opponents of altitude training argue that an athlete's red blood cell concentration returns to normal levels within days of returning to sea level and that it is impossible to train at the same intensity that one could at sea level, reducing the training effect and wasting training time due to altitude sickness. Altitude simulation systems have enabled protocols that do not suffer from such compromises, and can be utilized closer to competition if necessary. Some devices would be considered portable.
A 2005 study showed that although the boosted VO2 max had returned to normal 15 days after the conclusion of an 18-day Live High Train Low protocol, the submaximal performance at ventilatory threshold was enhanced upon initial return to sea-level, and was even greater 15 days later.
Numerous other responses to altitude training have also been identified, including angiogenesis, glucose transport, glycolysis, and pH regulation, each of which may partially explain improved endurance performance independent of a larger number of red blood cells. Furthermore, exercising at altitude has been shown to cause muscular adjustments of selected gene transcripts, and improvement of mitochondrial properties in skeletal muscle.
In Finland, a scientist named Heikki Rusko has designed a "high-altitude house." The air inside the house, which is situated at sea level, is at normal pressure but modified to a low concentration of oxygen, about 15.3% (below the 20.9% at sea level), the same concentration as that at the altitudes often used for altitude training. Athletes live and sleep inside the house but perform their training outside (at normal oxygen concentrations at 20.9%). Rusko's results show improvements of EPO and red-cell levels. His technology has been commercialized and is being used by thousands of competitive athletes in cycling, triathlon, olympic endurance sports, professional football, basketball, hockey, soccer, and many other sports that can take advantage of the improvements in strength, speed, endurance, and recovery.