EXPOSURE TO ALTITUDE or hypoxia (reduced oxygen levels) is a challenge to the human body because oxygen is the primary source of energy for our cells. Under a state of hypoxia, the body strives to produce the required amounts of energy, with less oxygen available to do it.

Exposure to hypoxia stimulates upregulation of Hypoxia Inducible Factor (HIF-1), which promotes an improvement of the body’s oxygen utilisation system at every link in the chain. Initially, pulmonary oxygen absorption is enhanced to allow more oxygen to enter the system. At the same time the kidneys signal for an increase in Erythropoietin Hormone (EPO) which stimulates the production of Red Blood Cells (RBCs). An increase in RBCs (and haemoglobin as a sub-unit of the RBC) provides increased transportation for this extra oxygen throughout the body.

At the next level, certain growth factors (VEGF) trigger increased capillarisation, enabling increased oxygen delivery to tissues, muscles and brain. Finally, hypoxia causes a boost in production and rejuvenation of mitochondria (the body’s principle oxygen sink and the location of aerobic energy production) and mitochondrial enzymes, allowing more efficient use of oxygen for energy production and enhanced enzymatic anti-oxidative defence.

Aside from these primary systemic changes, exposure to hypoxia is known to have the following physiological effects:

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Decreased average Heart Rate and Blood Pressure Increased production & release of Human Growth Hormone Stimulation of fat burning metabolism Decreased oxidative stress from Free Radicals (Reactive Oxygen Species “ROS”)

While the physiological benefits associated with hypoxia can be obtained by living permanently at altitude, as a training technique for physical performance it has drawbacks since athletes cannot maintain the necessary exercise training load in oxygen-deficient air. In addition, permanent exposure to altitude often leads to muscle loss, suppression of the immune system and excessive fatigue.
Sporting Edge systems overcome these problems whilst allowing the full performance enhancing benefits of hypoxic training to be realised.

There are three common forms of altitude training that can provide the discussed physiological effects.


Sleeping At Altitude

Sleeping at Altitude, or “Living High, Training Low” (LHTL) is the most widely accepted and common technique used in altitude training. First introduced by Benjamin Levine and James Stray-Gundersen, it involves prolonged exposure to hypoxia at night with physical training sessions at sea-level during the day. Many controlled studies have shown the effectiveness of this regime, which has become an essential part of the training schedule of literally hundreds of top athletes and sportsmen and women.

Following the 1968 Olympic Games in Mexico City (altitude 7,200' / 2,200m) the world of athletic science virtually exploded with exploration of the effects of altitude on athletic performance. More than thirty years later it's no longer a secret that altitude can have a major effect on an athlete's competitive results.

Whilst some studies have not been able to demonstrate clearly the benefits associated with hypoxic training, a great many have provided compelling evidence of powerful mechanisms at work. One illustrative finding, from a study by Benjamin D. Levine and James Stray-Gundersen, published in the Journal of Applied Physiology in July 1997 found that when expressed as a 12 1/2 lap race on a standard 400m track, the "high-low" runners were more than half way to lapping their, formerly equal, "low-low" counterparts.


Exercising at Altitude (Train High)

Recent studies have shown that a combination of 2-3 moderate intensity hypoxic workouts per week, mixed into a sea-level training program can take performance enhancements to a level that is unreachable with only altitude sleeping programs.

A moderate intensity effort in a Sporting Edge environment will take the Arterial Oxygen Saturation (Sa02 = measure of percentage of blood with oxygen bound) down from its normal 98% to about 83-85% without the hyperventilation or dehydration associated with altitude workouts. A high intensity workout at sea-level will cause a de-saturation to only about 95%. This acute condition is strongly tied to both mitochondrial adaptations and a shift to anaerobic energy production. In turn, more stress is placed on the muscles and a demand is created for muscle rebuilding and energy production through fat metabolism.

"Nine days after training in hypoxia, significant increases were seen in all important parameters of the maximal aerobic as well as the anaerobic test. A significant increase of 7.0% was seen in the mean maximal oxygen uptake per kilogram body weight (VO2 max), and the mean maximal power output per kilogram body weight (Wmax) increased significantly by 7.4%. The mean values of both mean power per kilogram body weight and peak power per kilogram body weight increased significantly by 5.0%, and the time-to-peak decreased significantly by 37.7%".
- Meeuwsen T, Hendriksen IJ, Holewijn M. Research and Development Department, Netherlands Aeromedical Institute, Soesterberg, The Netherlands.

"The evidence supporting altitude as a benefit for health and fitness is now quite substantial. The indications are that either sleeping at altitude, or training at altitude will cause the body to adapt rapidly, resulting in; improvements in the cardiovascular system, oxygen carrying capacity of the blood, exercise tolerance, anaerobic exercise capacity and faster fuel burning. There is even evidence that there may be some kind of protection from heart disease following altitude training."
- Dr Greg Whyte and Charles Pedlar, PhD. English Institute of Sport.


Note: Individual performance gains and/or blood chemistry changes may be affected by a number of factors including, but not limited to, diet, training, racing program, state of fatigue, state of dehydration, mental preparedness etc.


Related Articles

Altitude Research
Various studies and articles
Click here to view documentation.