Sauna sessions could make you live longer
Saunas. Meditation. Relaxation. Increased Growth Hormone. Muscle Recovery. Heart Health. Disease Risk Reduction. Longevity.
A couple of weeks back, I had a conversation with
about saunas here on Notes. Around the same time, I received an email stating that my gym’s sauna & spa would be closed for two weeks due to renovations - a first world problem, I know… And just like that, this post was born!I’m sure you’ve all heard of people discussing the benefits of sauna and heat exposure the last few years. An activity highly preached by Prof. Huberman and Dr Rhonda Patrick. I’ve seen one too many Twitter / X posts stating that one of the things they’ve learnt and implemented in their lives from Huberman’s podcast is going to the sauna. I, myself, have now been regularly using it as opposed to the one-offs and honestly really love it. It may also be the Greek genes that miss the heat here in London that play a role into my love for it.
A bit of history on saunas; they originated in Finland over 2,000 years ago and still are a crucial part of their culture. They would be small rooms / buildings that they would go in for their heat session, and once done, it would be followed by a cold-water plunge or even a snow one to cool down. As sauna spread around the globe, there were countries that adopted it and are still part of their culture; Estonia even has a UNESCO-listed smoke sauna experience. In 2023, a documentary called “Smoke Sauna Sisterhood” came out, based in east Estonia which celebrated female solidarity and community through a group of Estonian women who continue this age-old tradition. For context, women even give birth in saunas in Estonia.
Sauna Types
For reference there are three types, (i) traditional, (ii) steam, and (iii) infrared. Their main difference in the heat source, which also affects the maximum temperature that can be reached and the humidity levels. In traditional sauna a heater is used which warms up the air, humidity tends to be low until water is poured over the heated stone raising the humidity temporarily. In a steam sauna (aka steam room), a generator boils water into steam, so humidity is nearing 100%. In an infrared sauna, infrared heaters are used that emit infrared light as radiant heat which is directly absorbed by the skin - similar humidity levels to a traditional one. Traditional ones tend to be the hottest around 70-100°C, followed by infrared at 45-65°C and then steam ones at 30-50°C.
Our body’s response to the sauna
When you step into a sauna, the surrounding increased temperature induces a mild hyperthermia, which is an increase in your body’s normal temperature. This change triggers a response that is known as a thermoregulatory response - a process involving the cardiovascular, neuroendrocrine, and cytoprotective (our cell protection) mechanisms working together to ensure homeostasis. This is a self-regulating process which work to maintain our body’s functional stability when exposed to external conditions - in this case heat.
Fun fact: All living organism (besides viruses) are able to maintain homeostasis.
I’ll cover the benefits of sauna in the following aspects:
(1) overall health - physical & mental
(2) growth hormone
(3) heart health
🧘🏻♀️ Overall Health
Finnish saunas have consistently shown decreases in the risk of health outcomes such as hypertension, cardiovascular disease, thromboembolism, dementia, and respiratory conditions. As well as, minimising the severity of musculoskeletal disorders, COVID-19, headache and flu, while also improving mental well-being, sleep, and longevity.1
As shown in the graphic above, the heat activates heat shock proteins. These help in preventing protein aggregation in the brain, this is seen in many neurodegenerative diseases (e.g., Alzheimer’s disease) and it’s a factor linked to neuroinflammation. Spending 30 mins at 73°C can boost the levels of heat shock proteins by 50%. Outside of the neurodegenerative disease protection, it also protects against cardiovascular disease (e.g., cardiomyopathy). Heat shock proteins are crucial for overall health, as they maintain the protein structure within our cells - so multiple benefits on that side.
The heat exposure itself is a stressor; this stimulates various pathways and mechanisms in our body, like that of cortisol reduction (our primary stress hormone) and DNA repair pathways (better cell health, less disease). 2 If our cortisol is lower, we are calmer and our sleep will automatically be better. Another characteristic that impacts the improved mood and mental health aspect is due to the release of dynorphin and endorphins.3 I’m sure you’ve heard of endorphins being released during exercise - these help relieve pain, reduce stress and improve your sense of well-being. Similarly, dynorphins are also neuropeptide which are involved in pain, addiction and mood regulation. Although dynorphins are “negative” as their release in our brains makes it think we’re in discomfort (which is partially true), this sets the scene for endorphins to be released and counteract that state. And hence, the enhanced effect on our mood and body post sauna, the euphoria one may say.
So, as endorphins are being released when we’re exposed to heat, this in combination with a meditation practice can increase the benefits the practice n-fold.4 Meditation itself has been proven to be associated with increased cortical thickness5 , it can help train and reshape your brain, which encourages and cultivates a state of clarity, peace, and focus. Focusing on your breathwork, and mindfulness while being exposed to the heat due to the release of these hormones and neuropeptides (endorphins), decrease in cortisol, the relaxation provided by the heat - let’s just say it is a powerful duo. You’re improving your overall health and well-being at the same time by enhancing mindfulness and focus.
📈 Growth Hormone
You might be a tad confused as to why as an adult you’d even have growth hormone. Human growth hormone (HGH) is what fuels our growth in childhood, but also helps maintain our tissues and organs throughout our lifespan. HGH is produced in the pituitary gland (the part of our brain that produced hormones, located at the base of our brain), but around 40s the amount produced by the pituitary gland slowly decreases. This decrease in HGH has been associated with frailty in older ages, as well as sarcopenic obesity (those that are obese and have a high body fat percentage but low skeletal mass and low muscle mass).6 Another very important role of HGH is its role in cell and tissue growth, metabolism, and tissue repair. Naturally, we produce growth hormone during the early stages of sleep (you can read my post all about sleep & napping here); so of course, as we are quite sleep deprived as a population in the west and tend to go to bed much later than we should that also affects the amount of HGH releases.
The good news? Well, sauna can help replenish that amount - but please don’t forget all the other aspects of sleep that come with. See the sauna as a further HGH release for your health and longevity! 😉
There are studies dating back to the 80s having proven so.7 In an 1986 study, seven men and women had two 1-hr sessions at 80°C in a traditional sauna, per day for a week. On day 3, they showed a 16-fold increase in their HGH levels.8 Another study showed that two 15-min sessions at 100°C dry heat with a 30-min cooling period resulted in a 5-fold increase of HGH levels.9 So, evidently there is benefit to it and it appears that the session duration and possibly cold exposure may have a direct effect on the amount released. If you’re like me and sauna post-workout, a study by Ftaiti et al. showed that the combo of exercise and heat exposure (i.e. sauna) induced an even higher rise in HGH. 10
Remember how we said that HGH plays a role in cell and tissue growth, well your sauna time will release HGH that means your muscle tissue post-workout can repair faster, and in the case of injuries it would speed up the healing process. So, spending some time after your workout will most likely not make you feel as sore the day after. The other aspect of strength is also bone health; HGH directly impacts bone growth and density as it stimulates IGF-1 (Insulin-like Growth Factor 1) which plays a main role in the activity of osteoblasts (our bone forming cells) and chondrocytes (the cells in our cartilage). So, especially in the older ages this plays a major role in overall physical health, and making oneself more resilient to falls and accidents.
The last aspect of HGH is around metabolism; HGH stimulates lipolysis. A process in which lipids (fats and oils) are broken down and converted to glycerol and three fatty acids. What does this mean for our body? Well, more fatty acids are available for energy use, so less fat is stored. 11
🫀 Heart Health
Many studies have concluded that regular sauna is inversely associated with cardiovascular disease (CVD), in both males and females. A BMJ study, concluded that this association had to do both with the frequency of the sauna visits as well as their duration.12 Specifically, this study found that the participants had reduced risk in CVD events and strokes that led to death. As shown from the graph below on the left, the green line which is ≥ 4 sessions per week has the lowest cumulative hazard for CVD across the follow-up period of the participants. Similarly, for the graph on the right, the green line which is sessions lasting more than 45 mins again had the lowest risk.
Why is that? Well, when you’re in a sauna your heart rate increases, that means that there is an increased amount of blood moving through your blood vessels (i.e., blood flow surges), and lastly your blood vessels expand (vasodilation) to cool down your body (same thing as when you’re working out and sweating). The aspect of increased heart rate mimics exercise, so your heart is working out during the sauna sessions - a cardio workout to be precise. Another aspect is that sauna is associated with lower blood pressure; this is due to the blood vessels expanding.
Sauna and heat exposure evidently have many benefits, both short- and long-term. Regardless of the frequency or duration of sessions you can still get something positive out of it - which is rare for most things when done inconsistently. When I did my first sessions I could just about last 10-15 mins and let me tell you I also dreaded the cold shower that came with. Now, I can last up to 45 mins (I easily outcompete all the gym bros in the sauna, and I love it haha) and I just feel so relaxed and calm after it. I think it is also a bit “meditative” in the sense that you’re sat there, trying to control your breathing (read here about correct breaths) and kind of alone in your head. I’ve yet to master the full 45 mins being in a meditation state, but I guess even part of it adds to the benefits and overall state of good well-being. Don’t get me wrong some people do talk, and I’ve bumped into familiar faces when in the sauna so not every session is the same. Nonetheless, still feel that relaxation afterward. 🧘🏻♀️
The other aspect I love, is that I am free from my phone and any sort of distractions for at least an hour and so is everyone around me. Although, that being said I have seen some people bring phones in the 80-90°C sauna - which (i) makes me worried about the longevity of their phone, and (ii) concerned as to why they can’t take even a 30 min break from it!
The only thing I would suggest is be hydrated enough and take water with you - if you’re in for a long session I tend to have at least 1 L of water during the session and enough beforehand. Otherwise, you will get very dehydrated and possibly get a headache / migraine shortly after - speaking from experience - especially if you’re doing long sessions. Also, proper hydration also means electrolytes hydrates. Whether that’s from coconut water or orange juice, or even bone broth it will help you so much more.
I would love to hear your thoughts on sauna, and how it has benefited you! 🧖🏻♀️
I hope you enjoyed, thank you for taking some time out of your day to read my posts! See you next week! :)
Other similar or mentioned post:
All About Collagen
The Power of Creatine
The Heartbeat of Longevity
Nap Away
Laukkanen, J. A., & Kunutsor, S. K. (2024). The multifaceted benefits of passive heat therapies for extending the healthspan: A comprehensive review with a focus on Finnish sauna. Temperature (Austin, Tex.), 11(1), 27–51. https://doi.org/10.1080/23328940.2023.2300623
Podstawski R, Borysławski K, Pomianowski A, Krystkiewicz W, Żurek P. Endocrine Effects of Repeated Hot Thermal Stress and Cold Water Immersion in Young Adult Men. American Journal of Men’s Health. 2021;15(2). doi:10.1177/15579883211008339
Holaday, J. W., Wei, E., Loh, H. H., & Li, C. H. (1978). Endorphins may function in heat adaptation. Proceedings of the National Academy of Sciences of the United States of America, 75(6), 2923–2927. https://doi.org/10.1073/pnas.75.6.2923
Lazar SW, et al.. Meditation experience is associated with increased cortical thickness. Neuroreport. 2005 Nov 28;16(17):1893-7. doi: 10.1097/01.wnr.0000186598.66243.19. PMID: 16272874; PMCID: PMC1361002.
Garcia JM, Merriam GR, Kargi AY. Growth Hormone in Aging. [Updated 2019 Oct 7]. In: Feingold KR, Anawalt B, Blackman MR, et al., editors. Endotext [Internet]. South Dartmouth (MA): MDText.com, Inc.; 2000-. Available from: https://www.ncbi.nlm.nih.gov/sites/books/NBK279163/
Kukkonen-Harjula K, Kauppinen K. How the sauna affects the endocrine system. Ann Clin Res. 1988;20(4):262-266. PMID: 3218898
Leppäluoto, Juhani, et al. "Endocrine effects of repeated sauna bathing". Acta Physiologica Scandinavica, vol. 128, no. 3, 1986, p. 467-470. https://doi.org/10.1111/j.1748-1716.1986.tb08000.x
Kukkonen-Harjula, Katriina, et al. "Haemodynamic and hormonal responses to heat exposure in a finnish sauna bath". European Journal of Applied Physiology and Occupational Physiology, vol. 58, no. 5, 1989, p. 543-550. https://doi.org/10.1007/bf02330710
Ftaiti, Foued et al. “Effect of hyperthermia and physical activity on circulating growth hormone.” Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme vol. 33,5 (2008): 880-7. doi:10.1139/H08-073
Carrel, A. L., & Allen, D. B. (2000). Effects of growth hormone on adipose tissue. Journal of pediatric endocrinology & metabolism : JPEM, 13 Suppl 2, 1003–1009. PMID: 11086655.
Laukkanen, T., Kunutsor, S.K., Khan, H. et al. Sauna bathing is associated with reduced cardiovascular mortality and improves risk prediction in men and women: a prospective cohort study. BMC Med 16, 219 (2018). https://doi.org/10.1186/s12916-018-1198-0
Sara, I am humbled to appear in your text! The way you described saunas makes me want to go visit one right now! Since I am a huge fan of cold exposure, I believe adding heat exposure to the mix will balance my experiences. Personally I like steam sauna the best, but the last time I have visited one was 2 years ago for the best. Cheers and keep on good writing!
Is there any difference between a sauna and a steam room as far as these benefits are concerned?