Physical reactions to heat
In the sauna, our bodies react to the heat in different ways. One of the body’s reactions to heat is increased sweat production. When we are in a hot environment like a sauna, our sweat glands begin to work to cool our bodies. Sweat evaporates on the surface of the skin and removes heat from the body, resulting in natural cooling.
In addition to vasodilation and increased sweat production, heat can also lead to accelerated breathing. When we are exposed to high heat, our respiratory rate increases in order to provide the body with adequate oxygen. This increased oxygen demand is due to increased metabolic activity and the body’s effort to regulate body temperature.
In addition, heat also increases the heart rate. Due to the dilation of blood vessels and increased blood flow to the skin, the heart must work harder to pump blood throughout the body. An increased heart rate is a natural response to the heat and helps maintain the increased blood flow and keep the body cool.
The release of endorphins
The release of endorphins is another notable physical response to heat, especially during a sauna session. Endorphins are natural painkillers produced by our bodies. They are one of the body’s substances with opioid-like effects and are known to evoke positive emotions and a sense of well-being.
As we experience the increased body heat and blood flow in the sauna, the release of endorphins in our brain is stimulated. This occurs in response to the physical stress our bodies are subjected to during the heat. Endorphins are produced and released in the hypothalamus, the area of our brain responsible for regulating emotions and pain sensations.
Once released, endorphins bind to specific receptors in our nervous system, primarily those called opioid receptors. By activating these receptors, endorphins have a number of positive effects on our mood and overall well-being. We can experience a sense of relaxation, happiness, and euphoria often referred to as a “runner’s high”. It is a state of mental and physical relaxation and contentment that gives us a sense of inner peace and balance.
The release of endorphins during a sauna session can also provide a pain-relieving effect. The opioid-like effects of endorphins can help reduce pain and discomfort by acting on pain receptors in the brain and reducing their sensitivity.
However, the release of endorphins can vary from person to person. In some people, the release of endorphins and the associated positive effect is more intense, while in others it is less so. Nevertheless, the potential benefits of endorphin release during a sauna session are another aspect that underscores the positive effects of heat on our body and mind.
Scientific studies
Scientific studies have sparked interest in the effects of sauna visits on the release of endorphins. One such study, published in the journal Pain Research and Management, found that even a single sauna session can lead to a significant increase in blood endorphin levels. Blood was drawn from the study participants before and after the sauna session, and the results showed a significant increase in endorphin levels after the sauna session. This suggests that the heat and physical exertion during a sauna session may stimulate the release of endorphins.
Another interesting study published in the European Journal of Pain examined the long-term effects of regular sauna visits on pain tolerance and endorphin production. In this study, participants took regular saunas over a period of several weeks.
At the end of the study, participants exhibited increased pain tolerance, as measured by various pain tests, and increased production of endorphins. This suggests that regular sauna visits over an extended period of time may lead to an adaptation of the body that results in increased pain tolerance and increased release of endorphins.
The role of heat and cold stimuli
The role of heat and cold stimuli in the release of endorphins should not be underestimated. The alternation between heat and cold during a sauna visit can trigger a synergistic effect and enhance the positive effects on endorphin release.
When we warm up in the sauna, our blood vessels dilate, blood flow to the skin increases and the release of endorphins is stimulated. This helps to relax and improve our mood. The abrupt change from the sauna to a cold shower, plunge pool or ice bath provides a strong cold stimulus. These cold stimuli cause blood vessels to contract rapidly to protect the body from cold damage.
This alternation between vasodilation (widening of blood vessels) and vasoconstriction (narrowing of blood vessels) creates an intense stimulus to the nervous system. It is believed that this alternation between heat and cold further stimulates the release of endorphins. The sudden difference in temperature amplifies the body’s response and increases the feeling of well-being and relaxation.
Sources:
- (Cramer et al., 2017): Cramer, M. N., Jay, O., & Hodges, A. N. (2017). Human cutaneous thermoregulation during exercise. Temperature, 4(3), 227-247.
- (Scoon et al., 2007): Scoon, G. S., Hopkins, W. G., Mayhew, S., & Cotter, J. D. (2007). Effect of post-exercise sauna bathing on the endurance performance of competitive male runners. Journal of Science and Medicine in Sport, 10(4), 259-262.
- (Vaile et al., 2008): Vaile, J., Halson, S., Gill, N., & Dawson, B. (2008). Effect of hydrotherapy on recovery from fatigue. International Journal of Sports Medicine, 29(07), 539-544.
- (Ely et al., 2016): Ely, B. R., Farina, K. A., Hanson, E. D., & Perreault, L. (2016). Acute effects of sauna bathing on cardiovascular function. Journal of Human Hypertension, 30(3), 168-172.
- (Brenke et al., 2020): Brenke, R., Siems, W., Warnecke, C., Menzel, A., & Stangl, V. (2020).
