Infrared sauna
Encyclopedia
An infrared sauna uses infrared heaters
to emit infrared
radiant heat
which is absorbed directly into the human body, unlike traditional sauna
s which heat the body indirectly via air or steam.
Another benefit claim is that since saunas increase perspiration, they purportedly liberate undisclosed "toxins." Saunas have been recommended for this ostensible reason to people who are told they have high levels of "toxicity" in their body, although the supposed, offending toxins are rarely identified. Saunas may be useful to those who cannot sweat from exercise due to their health problems, such as Chronic Fatigue Syndrome
.
Only if the sauna uses far-infrared technology, the sauna might be more tolerated by patients who don't tolerate the high temperatures of the standard humid hot air saunas. This is because far-infrared rays do not heat the air inside the sauna, but they still heat the body. However, most infrared saunas in the market do not use the expensive far-infrared panels, which can be touched because they remain always cold, but much the cheaper low and medium-infrared heaters, which remain very hot when used and also heat the air of the sauna.
in the body. Proponents typically quote the Journal of the American Medical Association
stating: "A moderately conditioned person can easily sweat off 500 grams in a sauna, consuming nearly 300 kcal, which is equivalent to running 2–3 miles. A heat-conditioned person can easily sweat off 600–800 kcal with no adverse effects. While the weight of the water loss can be regained by drinking water, the calories consumed will not be." This statement is based on the amount of energy absorbed by sweat evaporating from the skin. It is equivalent to the latent heat of vaporization
of water, which is 539 kcal/kg (2260 kJ/kg). The source of this energy is then confused to be body energy stores, while the source is in fact the excessive heat absorbed from the sauna. The body reacts to the excess heat flux
by increasing perspiration. This does not increase body heat generation and calorie burn.
Infrared heater
An infrared heater is a body with a higher temperature which transfers energy to a body with a lower temperature through electromagnetic radiation. Depending on the temperature of the emitting body, the wavelength of the infrared radiation ranges from 780 nm to 1 mm. The relationship...
to emit infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
radiant heat
Thermal radiation
Thermal radiation is electromagnetic radiation generated by the thermal motion of charged particles in matter. All matter with a temperature greater than absolute zero emits thermal radiation....
which is absorbed directly into the human body, unlike traditional sauna
Sauna
A sauna is a small room or house designed as a place to experience dry or wet heat sessions, or an establishment with one or more of these and auxiliary facilities....
s which heat the body indirectly via air or steam.
Health benefit claims
A study of patients with rheumatoid arthritis and ankylosing spondylitis showed a reduction in pain, stiffness and fatigue during infrared sauna therapy, but this could have been due only to chance (i.e. not the sauna) as "these did not reach statistical significance."Another benefit claim is that since saunas increase perspiration, they purportedly liberate undisclosed "toxins." Saunas have been recommended for this ostensible reason to people who are told they have high levels of "toxicity" in their body, although the supposed, offending toxins are rarely identified. Saunas may be useful to those who cannot sweat from exercise due to their health problems, such as Chronic Fatigue Syndrome
Chronic fatigue syndrome
Chronic fatigue syndrome is the most common name used to designate a significantly debilitating medical disorder or group of disorders generally defined by persistent fatigue accompanied by other specific symptoms for a minimum of six months, not due to ongoing exertion, not substantially...
.
Only if the sauna uses far-infrared technology, the sauna might be more tolerated by patients who don't tolerate the high temperatures of the standard humid hot air saunas. This is because far-infrared rays do not heat the air inside the sauna, but they still heat the body. However, most infrared saunas in the market do not use the expensive far-infrared panels, which can be touched because they remain always cold, but much the cheaper low and medium-infrared heaters, which remain very hot when used and also heat the air of the sauna.
Energy expenditure and weight loss
Some infrared sauna proponents claim that the sauna is an effective method for considerably raising the rate of energy expenditureBasal metabolic rate
Basal Metabolic Rate , and the closely related resting metabolic rate , is the amount of daily energy expended by humans and other animals at rest. Rest is defined as existing in a neutrally temperate environment while in the post-absorptive state...
in the body. Proponents typically quote the Journal of the American Medical Association
Journal of the American Medical Association
The Journal of the American Medical Association is a weekly, peer-reviewed, medical journal, published by the American Medical Association. Beginning in July 2011, the editor in chief will be Howard C. Bauchner, vice chairman of pediatrics at Boston University’s School of Medicine, replacing ...
stating: "A moderately conditioned person can easily sweat off 500 grams in a sauna, consuming nearly 300 kcal, which is equivalent to running 2–3 miles. A heat-conditioned person can easily sweat off 600–800 kcal with no adverse effects. While the weight of the water loss can be regained by drinking water, the calories consumed will not be." This statement is based on the amount of energy absorbed by sweat evaporating from the skin. It is equivalent to the latent heat of vaporization
Latent heat
Latent heat is the heat released or absorbed by a chemical substance or a thermodynamic system during a process that occurs without a change in temperature. A typical example is a change of state of matter, meaning a phase transition such as the melting of ice or the boiling of water. The term was...
of water, which is 539 kcal/kg (2260 kJ/kg). The source of this energy is then confused to be body energy stores, while the source is in fact the excessive heat absorbed from the sauna. The body reacts to the excess heat flux
Heat flux
Heat flux or thermal flux is the rate of heat energy transfer through a given surface. The SI derived unit of heat rate is joule per second, or watt. Heat flux is the heat rate per unit area. In SI units, heat flux is measured in W/m2]. Heat rate is a scalar quantity, while heat flux is a vectorial...
by increasing perspiration. This does not increase body heat generation and calorie burn.