Sauna as a form of thermotherapy
It feels good to be in the sauna because our bodies respond to the heat. We sense the temperature through the skin, which sends a signal to the hypothalamus, which in turn triggers the release of certain hormones that are associated with “feeling food”. As our breathing rate increases, so does our blood circulation and we feel a pleasant sensation similar to that of exercise.
Whilst in the sauna, your body will keep working, as if under physical stress, similar to exercise. This means that the heart will keep on pumping more blood to supply all of your cells to keep up with demand due to increased heat. This will require lungs to be more active, increasing oxygen intake to oxygenate blood. Increase in oxygen intake is associated with positive emotions.
How infrared sauna use benefits the entire body
Since the ancient times sauna use had been associated with boosting health rather than just a place to relax. Naturally, the scientific community began to investigate potential therapeutic benefits of sauna use for both mind and body. Extensive research into body thermoregulation and particularly human body's response to heat stress is still being investigated with promising results.
Many of the claims brought forward regarding the health benefits of sauna use had been confirmed by scientists. Some of the more recent research into the effects of heat treatment had pleasantly surprised even long time advocates of sauna use. Studies confirmed that sauna is a viable method of both prevention and treatment of different conditions.
As stated in the article in the Evidence Based Complementary Alternative Medicine "Regular infrared and/or Finnish sauna bathing has the potential to provide many beneficial health effects, especially for those with cardiovascular-related and rheumatological disease, as well as athletes seeking improved exercise performance (4).
Saunas use is good for the brain, it also helps against anxiety, stress and depression.
The same summary study have noted multiple psychological benefits
"The psychological impact of sauna bathing may be due to a combination of factors that include release of endorphins and other opioid-like peptides such as dynorphins forced mindfulness, psychological stress reduction, relaxation, improved sleep, time out from busy life schedules, placebo effects, and other aspects of individual psychological and social interactions that likely occur around frequent sauna activity. (4)"
Further studies psychology have found a significant amount of evidence to support the use of sauna for treatment of depression, even in the long-term (5).
Moreover, evidence is emerging to suggest sauna as a method for prevention of cognitive impairment conditions in later life such as dementia, Parkinson's and Alzheimer's.
Thermoregulation and body response to heat stress as a treatment
Infrared sauna and other activities that increase body temperature, such as exercise, chilling on a beach and consuming hot beverages do bring some universal benefits.
Humans have adapted to respond to the environment. Nerve endings in the skin sense the change in temperature and the rate of change and send a signal to the hypothalamus, which is an area of the brain which is responsible for maintenance of internal environment of the body. These signals initiate a response from the nervous system to prevent the core body temperature rising or falling to dangerous levels. This process is called thermoregulation.
The nervous system responds according to the signals it receives. For example when it is cold then we begin to shiver, our hair follicles rise. Blood vessels that would otherwise transport warm blood from the internal organs to the cold skin, where the blood would lose heat, constrict, constraining most blood, and its heat, to the internal organs.
Body response to rising and falling temperature
Cold: Shivering, hair follicles rising, blood drains away fromthe skin, vessels close to the cold skin constrict
Hot: Sweating, hair follicles falling, blood drains away from the internal organs, vessels close to the hot skin expand
In response to heat your heart starts to race, much like cardiovascular exercise. The heart rate increases to between 100 and 150 beats per minute (1). Among the benefits there is an increased plasma and blood flow to the heart which is beneficial for the cardiovascular system.
The brain is affected as well. More blood flow to the brain means that mood improves. Additional blood flow from exercise and sauna uses alleviates symptoms of certain conditions such as depression. Furthermore, research shows that raising the body temperature in a sauna can help against anxiety and can help counter stress. Regular use has been shown to be beneficial in the long term for cognitive health too. Studies that show the benefits of sauna use for brain function, having similar effects to those of physical activities such as exercise.