Types of sauna
Currently, the most common form of thermotherapy used worldwide is the Finnish one, which involves short exposures of 5-20 minutes of the body to temperatures between 80 and 100°C (176°F - 212°F), in conditions of relative humidity (between 10 and 20% humidity) , interspersed with periods of humidity created by pouring water on the surface of the heat source (rock or hot coal).
In the last decade, a new type of sauna has become popular among people who prefer this type of thermotherapy, which involves the use of infrared emitters at different wavelengths, which generate temperatures lower than 45-60°C (113°F - 140°F) in a dry atmosphere (without steam ) namely infrared sauna . The principle of the infrared sauna is similar to the Finnish one, but it is easier to use in beauty salons or spas that do not benefit from extensive space and the financial resources necessary to build a classic sauna.
Both wet and dry Finnish saunas can include periods of body cooling by immersion in cold water and oral rehydration by drinking fluids before, during and after thermotherapy.
When is the sauna contraindicated from a medical point of view?
The main contraindications of the wet/dry sauna include a series of pathologies that can be aggravated during exposure to high temperatures, namely:
- Bronchial asthma
- Cardiac pathologies
- Epilepsy
- Hypotension or hypertension
- Pregnancy period
Alcohol consumption and psychoactive medication treatments are other contraindications for practicing sauna thermotherapy.
People who have required recent dental extractions or other types of surgical interventions are advised to avoid exposure to high temperatures due to the effect of increasing heart rate and vasodilation that can generate bleeding at the wound level.
Children up to 6 years of age have limited body temperature regulation mechanisms, so in their case it is recommended to avoid saunas to prevent the occurrence of hydroelectrolytic imbalances with increased risk of unfavorable evolution in this age category.
As a rule, we recommend limited exposure (maximum 10 minutes each) and supervised exposure to the heat generated in the sauna for children under 12 years old, with the removal of restrictions after this age or after reaching puberty.
What therapeutic benefits does the sauna have?
Exposure to heat during the sauna has the effect of increasing the skin temperature with the activation of thermoregulation at the level of the hypothalamus and the central nervous system with action on the autonomic nervous system. The activation of the sympathetic nervous system, the hypothalamic-pituitary-adrenal axis and the renin-angiotensin-aldosterone system causes changes in the cardiovascular system manifested by an increase in heart rate, intensification of blood circulation in the skin and loss of water and electrolytes through profuse sweating.
At the cellular level, thermotherapy in both dry and wet form induces discrete metabolic changes that include:
- Elderberry protein synthesis
- Reduction of reactive oxygen species and oxidative stress
- Reducing inflammation
- Increasing the availability of nitric oxide (important antiatherosclerotic role) and the sensitivity of cell receptors to insulin.
These changes due to the exposure of the body to high temperature are similar to those that occur during physical exercises, but the mechanisms that contribute to the emergence of therapeutic effects and to the improvement of the health of people who take sauna are still unclear.
The main benefits of the sauna include:
- Improvement of the symptoms associated with congestive heart failure by decreasing the cardiothoracic rate, increasing the patients' exercise tolerance and improving the NYHA risk class after visiting the sauna for a period of 2 weeks.
- Reducing the risk of heart rhythm disorders in patients with congestive heart failure.
- Improving the clinical manifestations associated with chronic arterial insufficiency by reducing pain discomfort, increasing exercise tolerance (assessed by increasing the distance traveled by the patient until pain occurs) and improving the ankle-brachial index.
- Improvement of cardiac perfusion (myocardial irrigation degree) in patients with coronary artery occlusions who have no indication for percutaneous transluminal coronary angioplasty.
- Reduction of stiffness and pain discomfort associated with rheumatoid arthritis and fibromyalgia.
- Reducing the frequency of acute headaches in patients diagnosed with chronic migraine.
- Reducing the risk of dementia and its clinical manifestations.
- Improvement of symptoms associated with bronchial asthma and clinically manifest allergic rhinitis with a reduction in the frequency of exacerbations.
Sauna - possible risks
Adverse effects of sauna thermotherapy include moderate heat discomfort, clinically manifest hypotension, hypovolemia, polyuria and, in rare cases, bleeding at the level of surgical wounds or post-dental extraction.
Certain studies have highlighted the existence of a significant negative effect of this type of thermotherapy on spermatogenesis, in the sense of decreasing the number of spermatozoa and their mobility in the ejaculate in men who frequented the sauna for 15 minutes a week for a period of at least 3 months. Fortunately, the effect is reversible, sperm production returning to normal approximately 6 months after stopping sauna use, but this aspect is important to know, especially for men with oligo or asthenozoospermia who want to conceive a child.
Useful tips before going to the sauna
Reducing the risks involved in exposure to high temperatures during the sauna can be achieved by applying some rules that involve:
- Avoiding alcohol consumption before and after thermotherapy.
- The gradual increase through successive sessions of the time spent in the sauna from 5 minutes to a maximum of 20 minutes/session.
- Avoiding large meals before the sauna.
- Supplementation of water intake after completing the session to compensate for fluid losses from the skin.
- Interruption of the thermotherapy session in the event of dizziness, nausea and/or vomiting or headache.
