There is a growing body of research indicating that sauna use is associated with many health benefits, ranging from improved endurance to excretion of certain toxins. As you would probably expect, sauna use results in a lot of sweating, which is actually responsible for delivering many of the benefits. According to research compiled by Dr. Rhonda Patrick, “the average person loses approximately 0.5 kg (1.1lbs) of fluid as sweat during a single sauna session”1.With intense sweating comes the risk of dehydration. We are not suggesting you avoid the sauna, but you should have a hydration plan to avoid the deleterious effects of dehydration (outlined in Optimal Hydration). The easiest way to do this is by drinking water before and during sauna use. The confounding factor of sauna hydration is that your water bottle will be subjected to high temperatures. In fact, only a handful of bottles are appropriate during this activity.
Plastic Water Bottles in the Sauna
Given the high temperatures found in the sauna you need to choose your water bottle wisely. Studies have indicated that plastic will release more BPA when exposed to hot water2. Exposure to BPA is associated with higher risk for a number of medical disorders including diabetes and cardiovascular disease3. Therefore, we do not advise using plastic water bottles in the sauna. The irony here is that there is some evidence to indicate that sauna use may facilitate your body’s excretion of BPA4. Using a plastic water bottle in the sauna could possibly increase your toxin load, eliminating a benefit of sauna use.
Best Water Bottles for the Sauna
At this time we can recommend two water bottles for use in the sauna, the Yominous and Yeti Rambler. The Yominous was tested specifically for this use-case and performed well. The rugged Yeti is another solid option and, per our conversation with the manufacturer, can withstand the heat of a sauna. More information is below.
- Yominous Water Bottle: Our team reviewed this bottle specifically for use in the sauna and found it to be a great option. As you’ll see in the article, the overall score for this bottle was pulled down by lower insulation and durability scores, but this is expected for a glass bottle. If you’re specifically looking for a bottle to endure the heat of a sauna, give Yominous a try.
- Yeti: We asked the Yeti team, and they indicated a Yeti Rambler would be appropriate for sauna use given its ability to withstand the temperatures found in a dishwasher. They recommended using a Yeti handle, a removable plastic handle that grips the side of the bottle, so you would not have to touch the hot metal exterior.
- The Sauna Bottle: Full disclosure, we haven’t tried this bottle and weren’t able to purchase it before the company ceased operations. This product, only sold on Amazon for a short period of time, was specifically designed for sauna use. Amazon stopped carrying the product in 2021 and a quick internet search will lead you to the for-sale domain name.
Note that many stainless steel bottles can be compromised with high heat (see our Stainless Steel Dishwashing Article for more background), so we do not want to suggest a use that may void the warranty or worse yet, ruin the bottle. For instance, Hydro Flask customer service does not recommend using their bottles in the sauna.
Best Electrolytes for the Sauna
Replacing electrolytes lost in sweat is also an important consideration for sauna use. If sauna use is accompanied with intense exercise or if it’s just a prolonged session, consider using an electrolyte mix instead of regular water. We’ve outlined a few that worked well for our reviewers:
- UCAN: With 3x the sodium of the average electrolyte, this product performs well under sweaty conditions. This is a great option for someone who plans on spending a few extra minutes in the sauna, but doesn’t need the next level of salt intake that you’d get from a brand like LMNT.
- LMNT: Our reviewers found this mix is best suited for intense exercise or perspiration given its high sodium (1000mg) content. If you are hitting the sauna after a long workout, LMNT would be a good choice. It’s also one of our favorite tasting electrolyte mixes.
- Dr. Price’s: One of our all-around favorites, Dr. Price’s mix provides salt, magnesium, and potassium to replenish the top electrolytes lost during sweat. It has an overall lower electrolyte content than the first two options, but still packs a punch.
- Ultima Replenisher: This refreshing electrolyte mix also contains a good balance of minerals to maintain bodily functions. The lemonade flavor is a favorite among our reviewers. Electrolyte levels are more in line with Dr. Price’s than LMNT.
The sauna can be a fun and healthy activity if you are prepared to stay hydrated. Remember to always consult a physician before starting to use a sauna.
1 Patrick, Rhonda. “Sauna.” Found My Fitness, www.foundmyfitness.com/topics/sauna#bibid-73b0f31ad82e990e921d78736e4603e9. Accessed 18 Feb. 2021.
2Cooper, James E et al. “Assessment of bisphenol A released from reusable plastic, aluminium and stainless steel water bottles.” Chemosphere vol. 85,6 (2011): 943-7. doi:10.1016/j.chemosphere.2011.06.060
3Lang IA, Galloway TS, Scarlett A, et al. Association of Urinary Bisphenol A Concentration With Medical Disorders and Laboratory Abnormalities in Adults. JAMA. 2008;300(11):1303–1310. doi:10.1001/jama.300.11.1303
4Stephen J. Genuis, Sanjay Beesoon, Detlef Birkholz, Rebecca A. Lobo, “Human Excretion of Bisphenol A: Blood, Urine, and Sweat (BUS) Study”, Journal of Environmental and Public Health, vol. 2012, Article ID 185731, 10 pages, 2012. https://doi.org/10.1155/2012/185731