A perpetual process, an essential method of health preservation, sweating is undervalued in today's world. In our age of intellectual work and sedentary lifestyle, people do not sweat nearly as much as it is required by nature in order to maintain a healthy chemical balance in the body. This is also aggrandized by the use of antiperspirants, synthetic clothing as well as by a polluted air of big cities.
The air temperature of 175-215 °F and the humidity of around 15-25% make Russian banya one of the most efficient ways to intensify sweating. The number of sweat glands in the human body is enormous and amounts to around 200 per square inch. When a person is in a banya these numerous eccrine sweat glands trigger an intensive reaction to heat. Fifteen minutes in a sauna may lead to the secretion of up to 34 ounces of sweat. Its total volume is estimated to be in a range of 0.7-1.0 oz/minute, in some cases - up to 1.5 oz/minute. The actual amount is influenced by such factors as air temperature, duration of exposure to heat, procedures used (e.g. the venik platza).
Significant perspiration starts when body surface temperature reaches 105 °F. It is at that temperature when skin pores actively open and collateral capillary vessels join the intense process of blood and lymph circulation. In fact, since the most of the work in terms of maintaining the optimal body temperature is done by the process of sweating, skin surface remains crucial for heat exchange.
Sweat also cleans the body from toxic substances, such as copper, lead, zinc, mercury, and lactic acid - the product of muscular anaerobic metabolism. The cleaning effect of 15-minute banya session equals approximately 24 hours of kidney work in terms of detoxing. In Finland sauna is used to treat people who work in chemical factories.
There are a great number of scientific studies that provide a detailed explanation of the influence of heat on human body. The process of hyperthermia treatment of disease by inducing a fever became a popular topic in various spheres of medicine.
For a modern person, a visit to Russian sauna might be one of the most physically intensive activities available. Seeming relaxation is combined with intensified work-load for all internal organs, which can be compared to jogging. At the same time the body is actively cleansed and detoxified though sweating. Body surface temperature can go up to almost 115 °F, while temperature of internal organs is increased by not more than 6 °F, which is enough to achieve the benefits of the "healing fever" that, according to Hippocrates, will cure any disease.
The inner temperature rise also affects the function of important endocrine glands, the pituitary in particular. Located in the bottom center of the brain, the pituitary is known to be a "control panel" for the whole endocrine system, since its hormones regulate other glands (adrenal, thyroid, testes and ovaries) and metabolic processes in general. Under the influence of heat, the pituitary gland intensifies metabolism in the body and improves the balance of other hormones (there is even some evidence that sauna increases the sex drive). Heat also speeds up the work of the respiratory system, increasing body demand for oxygen by 20% and therefore promoting an intense body waste elimination through the lungs.
Even though it would be a bit of a stretch to assume this sauna-induced fever as an all-healing method (although some researchers believe it might be beneficial even for cancer patients), we still can safely attest that most of pathogenic viruses and bacteria are destroyed by this kind of body temperature increase. Also, there are reasons to think that damaged cells and tissues recover much faster under high temperature due to intensified metabolic processes. Artificial fever created by banya induces the intensified production of lymphocytes and blood interferon, an anti-viral protein. Before the antibiotic era, doctors were aware of this and used minor diseases that are accompanied by fever to treat other more serious maladies.
One more way in which banya improves peoples sense of well-being and emotional state is an abundance of negative ions in saunas. In fact, Columbia University studies of people with winter and chronic depression show that negative ions relieve depression as much as antidepressants. Other researches have shown that pouring water on hot stones in banya releases an enormous amount of negative ions and is one of the underlying reasons for the feeling of relaxation and an improved emotional state.