Intermittent hypoxic exposure (IHE) is exposure to short periods of hypoxic air at rest (9-15% oxygen) alternated with normoxic air (21% oxygen). This technique was originally trialled by Russian aviators in attempts to preacclimatize pilots to the high altitudes encountered during sojourns in open cockpit planes.
Most of the attention devoted to altitude training in the recent past has focused on how it increases the number of red blood cells. This quantity, or percentage, of red blood cells is termed hematocrit. Since the 1970’s in sports the illegal practice of blood doping has over emphasized the significance of hematocrit in predicting athletic performance.
An average hematocrit for males is 43%. The legal limit for sports is 50%. When illegal doping is performed the goal is to get the red blood count up to 49.9%, without going over the limit. This can be accomplished by a blood transfusion, using an athlete’s own blood that is concentrated and stored in a refrigerator until a day before an event. It is then transfused into the athlete to provide an instant boost of his hematocrit from 43-49.5%. The athlete can also receive daily injections, over 15 days, of EPO, a drug hormone that stimulates red blood cell production causing similar increases in hematocrit.
While interval hypoxic exposure (IHE) and interval hypoxic training (IHT) can also increase hematocrit, it does so at a much lower rate, only about 2 percentage points, from 43 to 45%. Although (IHE) is legal and safe, this is considered too low for the athletes who elect to dope. Among the many problems of illegal transfusions and EPO is that it creates a severe imbalance in red blood cells leading to blood clots, strokes and heart attacks. In the late 1980's & 90's it lead to hematocrits of over 65% being reported, that caused the untimely deaths of dozens of professional cyclists. Aside from being dangerous, illegal and expensive, EPO has been shown to deplete myoglobin and reduce muscle function. Many of us know the fate of Lance Armstrong when he elected to go the illicit drug route. Even his doping guru, Dr. Michele Ferrari, said that he could have achieved his same results if he relied on altitude training alone.
In the overall picture, (IHE) is much safer, more effective, and less costly at improving athletic performance than blood doping, steroid, and human growth hormone use combined. When one compares the improvement of (IHE) on the muscle (45% body wt) and blood system (7% body wt) together, vs just the blood (7%) alone, this becomes clear. This was revealed by Mr. Dwain Chambers, who spent several years doing all the illegal things in his 20's, then went legitimate in his 30's and switched to AltoLab and went on to achieve all his personal bests in Olympic sprinting. He still holds the European record in the 60 m dash that he won when he was 32 years old, only 3 months after he started on an AltoLab program.