Altitude tent
Encyclopedia
An altitude tent, also known as an altitude simulation tent or a hypoxic tent, is an enclosed living space which simulates high altitude
by maintaining a lower oxygen
concentration. It is used by athletes and by high-altitude mountain climbers to stimulate the body's natural adaptations to altitude, including an increase in the number of red blood cells and enzymes. Red blood cells carry oxygen to the body; athletes benefit from increased delivery of oxygen to the muscles, and mountain climbers can avoid altitude sickness
by better utilizing the diminished amount of oxygen found at higher altitudes.
The basic concept of living or training at altitude is to cause the body to adapt to the lower oxygen content by producing more oxygen-carrying red blood cells and hemoglobin. This improves the athlete’s ability to perform work, because more oxygen is available to the working muscles.
Sleeping in a simulated altitude environment allows the body to achieve some of the positive adaptations to altitude while still permitting the athlete to perform workouts at an oxygen-rich lower altitude where muscles can perform at their normal work level. An altitude tent is one way to enable athletes living at any elevation sleep in a high altitude-like environment. A more expensive option gaining popularity amongst professional athletes is to convert their entire bedroom to altitude.
Rather than simulating altitude with actual low air pressure (which would require substantial engineering and the use of an airlock to prevent implosion), the altitude tent remains at normal air pressure, substituting low concentration of oxygen for low pressure. While normal air contains 20.9% oxygen
independent of altitude, the air in an altitude tent contains as little as 12% oxygen (the remainder being nitrogen
). The partial pressure
of oxygen inside the tent is the same as it is at the natural elevation that the tent is simulating.
Most altitude tents create the low-oxygen environment with a “hypoxic air generator” outside the tent pumping the hypoxic (low oxygen) air into the tent. This displaces the more oxygen-rich air inside the tent and with it the excess carbon dioxide
exhaled by the occupant(s). Most athletes use altitudes between 8,000 and 15,000 feet. To cause a physiological response, the altitude must be sufficient to reduce blood oxygen saturation (sometimes measured by a pulse oximeter
) to approximately 90%.
The tents themselves come in several styles. Unlike camping tents, altitude tents cannot have much ventilation, and often substitute clear plastic windows for the typical nylon and mesh vents. Displaced air escapes the tent through small outlets, seams, or zippers. Air delivery can be through hose long enough to allow the generator to be placed in a different room, reducing noise. Tents are typically placed on the bed, with the floor of the tent between mattress and box springs.
One challenge with altitude tents is the build up of heat and humidity. Because of the use of plastic panels to reduce exchange with the room, heat and humidity can build up in an altitude tent. Some tents allow the use of air conditioners to maintain comfortable conditions. Carbon dioxide
from exhaled air can also build up to uncomfortable levels if air exchange is too low. In recent years, advances in altitude tent design, and in the performance of the hypoxic air-supply units, have all resulted in greater air-exchange and significantly lower noise levels.
An alternative to the sealed altitude tent is the altitude canopy, which drapes over the user's bed, and features a weighted edge instead of a tent floor. The canopy maintains high altitude even though there may be small gaps around the edge by maintaining a high flow rate of hypoxic air through the canopy, effectively preventing room air from entering the gaps. By virtue of smaller internal volumes, canopies come to altitude faster than conventional altitude tents.
The ethics of the use of these devices by athletes has been discussed by the World Anti-Doping Agency
(WADA), which claimed that it could be equivalent to blood doping
and therefore they should be banned; however, on September 16, 2006, Dick Pound
of the WADA announced that "...the overwhelming consensus of our health, medicine and research committees – was that, at this time, it is not appropriate to do so," No explanation was given as to how WADA would have enforced a ban.
Altitude
Altitude or height is defined based on the context in which it is used . As a general definition, altitude is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The reference datum also often varies according to the context...
by maintaining a lower oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
concentration. It is used by athletes and by high-altitude mountain climbers to stimulate the body's natural adaptations to altitude, including an increase in the number of red blood cells and enzymes. Red blood cells carry oxygen to the body; athletes benefit from increased delivery of oxygen to the muscles, and mountain climbers can avoid altitude sickness
Altitude sickness
Altitude sickness—also known as acute mountain sickness , altitude illness, hypobaropathy, or soroche—is a pathological effect of high altitude on humans, caused by acute exposure to low partial pressure of oxygen at high altitude...
by better utilizing the diminished amount of oxygen found at higher altitudes.
The basic concept of living or training at altitude is to cause the body to adapt to the lower oxygen content by producing more oxygen-carrying red blood cells and hemoglobin. This improves the athlete’s ability to perform work, because more oxygen is available to the working muscles.
Sleeping in a simulated altitude environment allows the body to achieve some of the positive adaptations to altitude while still permitting the athlete to perform workouts at an oxygen-rich lower altitude where muscles can perform at their normal work level. An altitude tent is one way to enable athletes living at any elevation sleep in a high altitude-like environment. A more expensive option gaining popularity amongst professional athletes is to convert their entire bedroom to altitude.
Rather than simulating altitude with actual low air pressure (which would require substantial engineering and the use of an airlock to prevent implosion), the altitude tent remains at normal air pressure, substituting low concentration of oxygen for low pressure. While normal air contains 20.9% oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
independent of altitude, the air in an altitude tent contains as little as 12% oxygen (the remainder being nitrogen
Nitrogen
Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...
). The partial pressure
Partial pressure
In a mixture of ideal gases, each gas has a partial pressure which is the pressure which the gas would have if it alone occupied the volume. The total pressure of a gas mixture is the sum of the partial pressures of each individual gas in the mixture....
of oxygen inside the tent is the same as it is at the natural elevation that the tent is simulating.
Most altitude tents create the low-oxygen environment with a “hypoxic air generator” outside the tent pumping the hypoxic (low oxygen) air into the tent. This displaces the more oxygen-rich air inside the tent and with it the excess carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
exhaled by the occupant(s). Most athletes use altitudes between 8,000 and 15,000 feet. To cause a physiological response, the altitude must be sufficient to reduce blood oxygen saturation (sometimes measured by a pulse oximeter
Pulse oximeter
A pulse oximeter is a medical device that indirectly monitors the oxygen saturation of a patient's blood and changes in blood volume in the skin, producing a photoplethysmograph. It is often attached to a medical monitor so staff can see a patient's oxygenation at all times...
) to approximately 90%.
The tents themselves come in several styles. Unlike camping tents, altitude tents cannot have much ventilation, and often substitute clear plastic windows for the typical nylon and mesh vents. Displaced air escapes the tent through small outlets, seams, or zippers. Air delivery can be through hose long enough to allow the generator to be placed in a different room, reducing noise. Tents are typically placed on the bed, with the floor of the tent between mattress and box springs.
One challenge with altitude tents is the build up of heat and humidity. Because of the use of plastic panels to reduce exchange with the room, heat and humidity can build up in an altitude tent. Some tents allow the use of air conditioners to maintain comfortable conditions. Carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
from exhaled air can also build up to uncomfortable levels if air exchange is too low. In recent years, advances in altitude tent design, and in the performance of the hypoxic air-supply units, have all resulted in greater air-exchange and significantly lower noise levels.
An alternative to the sealed altitude tent is the altitude canopy, which drapes over the user's bed, and features a weighted edge instead of a tent floor. The canopy maintains high altitude even though there may be small gaps around the edge by maintaining a high flow rate of hypoxic air through the canopy, effectively preventing room air from entering the gaps. By virtue of smaller internal volumes, canopies come to altitude faster than conventional altitude tents.
The ethics of the use of these devices by athletes has been discussed by the World Anti-Doping Agency
World Anti-Doping Agency
The World Anti-Doping Agency , , is an independent foundation created through a collective initiative led by the International Olympic Committee . It was set up on November 10, 1999 in Lausanne, Switzerland, as a result of what was called the "Declaration of Lausanne", to promote, coordinate and...
(WADA), which claimed that it could be equivalent to blood doping
Blood doping
Blood doping is the practice of boosting the number of red blood cells in the bloodstream in order to enhance athletic performance. Because such blood cells carry oxygen from the lungs to the muscles, a higher concentration in the blood can improve an athlete’s aerobic capacity and...
and therefore they should be banned; however, on September 16, 2006, Dick Pound
Dick Pound
Richard William Duncan Pound, is a Canadian lawyer, partner of the law firm Stikeman Elliott, the former president of the World Anti-Doping Agency based in Montreal, and former chancellor of McGill University...
of the WADA announced that "...the overwhelming consensus of our health, medicine and research committees – was that, at this time, it is not appropriate to do so," No explanation was given as to how WADA would have enforced a ban.