Neuroscientist Andrew Huberman explains how a sauna helps strengthen the heart, improve sleep and rejuvenate organism.
“Going to the sauna is like being born again” - that’s what people though since ancient times. People visited the steam room to increase immunity and improve health. So, in the IV century BC. e. the ancient Greek physician and philosopher Hippocrates prescribed a sauna for various diseases.
Since then, more effective drugs have appeared. The sauna is now seen as a place to relax and meet friends, although some believe in the heat's ability to heal. But is steaming really helpful? In the Huberman Lab health podcast, neuroscientist Andrew Huberman answers this question based on scientific research.
About the expert: Andrew Huberman is a neuroscientist and professor at Stanford University. He runs the Huberman Laboratory at the Stanford School of Medicine. He specializes in research on the development and functioning of the brain, neuroplasticity, and the regeneration of neurons damaged by injury or disease.
Why sauna is useful
High temperatures in a steam room have a powerful effect on organism. Let's take a closer look at it.
The cardiovascular system
In hot conditions, blood vessels dilate, and the heart rate increases from 100 to 150 beats per minute, blood flow increases. The result is a safe and effective cardio workout. A study by an international team of scientists found that people who took a sauna four to seven times a week had a 50% lower risk of vascular disease. And for those who went twice a week - by 27%. The study involved 1688 people aged 53 to 74 years. Scientists tracked the health status of the respondents for 15 years.
Fat in the body performs many different functions, including helps regulate metabolism. There are three types of fat: white, beige and brown. In white, energy is stored, in addition, it serves as thermal insulation for internal organs. But if it becomes too much, it can lead to diabetes and obesity. Brown fat is responsible for thermoregulation: when a person is cold, it breaks down and raises body temperature. The more it is in the body, the lower the risk of type 2 diabetes and cardiovascular disease. Beige fat is an intermediate form between white and brown.
An adult has little brown fat. But there are ways to increase its amount in the body due to white fat. First of all, it is physical activity, as well as exposure to low and high temperatures. And if quite a lot is already known about the benefits of cold for the production of brown fat, then scientific articles about a similar effect of heat began to appear recently. For example, in a 2022 study, Chinese scientists found that at a temperature of 41 degrees Celsius, the amount of beige fat increases - it then turns into brown. In an experiment on mice, this mechanism helped rodents cope with obesity. It exists in humans too, and going to the sauna regularly is a good way to activate it.
Growth hormone (somatotropin) rejuvenates the body and helps muscles recover faster. Somatotropin is released during deep sleep. With age, its duration decreases, as does the amount of the hormone in the body. But a sauna can stimulate its production.
In a Finnish study, 17 participants aged 17 to 22 went to the sauna for two hours a day (four sessions of 30 minutes each) for a week. Results: on the first day, growth hormone increased 16 times, on the third - four times. That is, the body adapts to the conditions, and over time, the effect ceases to manifest itself. Therefore, to increase growth hormone, it is recommended to visit steam rooms no more than once every seven to ten days. Before going to the sauna, it is advisable not to eat for two hours.
Sauna involves many processes in the body, which potentially extend life. For example, it stimulates the production of the FOXO3 protein, which is involved in the DNA restoration and the cleansing of the body from aging cells. The more FOXO3 in the body, the higher the opportunity of living up to 100 years. The impact on dead cells also occurs from the outside - dry steam helps the keratinized particles of the skin to exfoliate, so that it becomes smooth. It turns out that the heat comprehensively contributes to the rejuvenation of the body.
High temperatures are stressful for the body. But since it is short-term, it stimulates the production of endorphins - neurotransmitters that relieve pain and discomfort sensations to give a person time and strength to escape from a threat.
If you have ever run long distances or been intensely trained, you may remember that after 10-15 minutes it gets hard. Muscles tense up, sometimes start to hurt, breathing goes astray. But then you seem to have a “second wind”: you feel lightness and joy. This is how endorphins work, and this effect also appears after a sauna - what you need after a hard day's work.
Steaming in the evening helps to improve the quality of sleep. The fact is that under the influence of circadian rhythms, shortly before going to bed and during the night, the temperature of the human body decreases. Before awakening, on the contrary, it rises. In a hot environment, the brain turns on the cooling mechanisms. And if you go to the sauna in the evening, the body will continue to cool. This will make the brain think that it is time for the body to rest, and it will be easier to fall asleep.
After a hearty meal or on an empty stomach, it is better not to visit the sauna. The optimal time is two hours after eating. Due to the heat outside, the blood is redirected from the internal organs to the skin to cool the body. For digestion, it is necessary that the stomach is well supplied with blood, otherwise the food will not be digested and will “roam” in the stomach.
Also, when exposed to hot air, the body loses moisture. Therefore, it is important to restore the water balance. On average, it is worth consuming 470 ml of liquid for every 10 minutes spent in the sauna. You should not drink alcohol and green tea - they will increase the load on the heart, and in the sauna it is already more than usual. You can safely use water and isotonics - an aqueous solution of mineral compounds that are necessary for the stable functioning of the body. It is also recommended to drink dried fruit compotes and herbal teas.
It is important to remember about contraindications. Do not steam during pregnancy, breastfeeding, serious heart diseases (ischemic disease, arrhythmia and tachycardia), tuberculosis, epilepsy and oncology. Even if you feel good and do not have conditions from the list above, the sauna is stressful for the body. Before visiting, you should consult with your doctor.
The material is for informational purposes only: We are not responsible for decisions made on the basis of the specified information.
Author: Victoria Semyanishcheva
Publication date: 27/01/2023