An infrared sauna uses infrared heaters to emit infrared light experienced as radiant heat which is absorbed by the surface of the skin. Traditional saunas heat the body primary by conduction and convection from the heated air and by radiation of the heated surfaces in the sauna room.
Arthritis
A study of patients with rheumatoid arthritis and ankylosing spondylitis showed a reduction in pain, stiffness and fatigue during infrared sauna therapy, but since results from the study "did not reach statistical significance" [3] there is no clear or certain relationship between reducing symptoms and using infrared sauna therapy.
Toxins
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.
Heat tolerance
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.[4] 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 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 expenditure 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.
