Saunas have become increasingly popular for relaxation, recovery, “detoxing” and weight loss. But what does the evidence actually show?
1. Can saunas support heart health?
Sauna bathing increases skin blood flow, heart rate and sweating. With repeated exposure, these responses may contribute to improvements in vascular function. (1)
A 2015 Finnish study following more than 2,300 middle-aged men for approximately 20 years found that frequent sauna use (4-7 times per week) was associated with lower cardiovascular and all-cause mortality. However, as an observational study, it cannot prove sauna itself caused the lower risk. (2)
More recent evidence is less conclusive. A 2025 meta-analysis of 20 randomised controlled trials investigating passive heat therapies found no significant overall improvements in most cardiovascular and metabolic markers. (3)
2. Do saunas improve exercise recovery?
The evidence is mixed. Some people find sauna relaxing after exercise, but research has not yet established that it meaningfully improves recovery or performance. (4)
Sleep, nutrition, hydration and appropriate training remain the foundations of recovery.
3. Do saunas “detox” the body?
Not in the way it is often advertised. Sweating primarily helps regulate body temperature. Your liver and kidneys do most of the work of processing and removing waste from the body.
4. Do saunas help with weight loss?
Any immediate drop in weight after a sauna is mainly due to fluid loss, not fat loss.
Once you rehydrate, most of this weight returns.
5. Can a sauna replace exercise?
No. Sauna does not provide the same benefits as exercise for cardiorespiratory fitness, muscular strength, bone health and physical function.
Take-home message
Sauna can be an enjoyable way to relax and may offer some cardiovascular benefits, but the evidence is still developing.
If you enjoy using a sauna, consider it an addition to regular exercise, good nutrition, adequate sleep and hydration — rather than a replacement for them.
References
- Laukkanen JA, Laukkanen T, Kunutsor SK. Cardiovascular and other health benefits of sauna bathing: a review of the evidence. Mayo Clin Proc. 2018;93(8):1111-1121. doi: 10.1016/j.mayocp.2018.04.008. PubMed
- Laukkanen T, Khan H, Zaccardi F, Laukkanen JA. Association between sauna bathing and fatal cardiovascular and all-cause mortality events. JAMA Intern Med. 2015;175(4):542-548. doi: 10.1001/jamainternmed.2014.8187. PubMed
- Hamaya R, Joyama Y, Miyata T, et al. Non-acute effects of passive heating interventions on cardiometabolic risk and vascular health: systematic review and meta-analysis of randomized controlled trials. Am J Prev Cardiol. 2025;23:101082. doi: 10.1016/j.ajpc.2025.101082. PubMed
- Ahokas EK, Hennessy RS, Hanstock HG, Kyröläinen H, Ihalainen JK. Effects of post-exercise heat exposure on acute recovery and training-induced performance adaptations: a systematic review. Sports Med Open. 2025;11(1):106. doi: 10.1186/s40798-025-00910-0. PubMed