Upregulated heat shock proteins
Both aerobic exercise and heat stress from sauna bathing increase the activity of heat shock proteins. A 2021 review published in Experimental Gerontology found that heat shock proteins become elevated in cells within 30 minutes of exposure to heat and remain elevated over time – an effect similar to exercise.
“Saunas increase heat shock proteins that break down old, dysfunctional proteins and then protect new proteins from becoming dysfunctional,” Hunter S. Waldman, PhD, an assistant professor of exercise science at the University of North Alabama in Florence, said. This effect is one way sauna bathing may quell systemic inflammation, Dr. Waldman said.
According to a 2018 review published in BioMed Research International, an abundance of heat shock proteins may increase exercise tolerance. The researchers concluded that the positive stress associated with elevated body temperature could help people be physically active for longer periods.
Added stress, especially heat-related strain, is not good for everyone, however. Dr. Waldman cautioned that heat exposure, be it through a sauna, hot tub, or other source, can be harmful for pregnant women and children and can be dangerous for people who have low blood pressure, since blood pressure often drops to rates that are lower than before taking a sauna. It also can impair semen quality for months after exposure, so people who are trying to conceive should avoid sauna bathing.
Anyone who has been diagnosed with a heart condition, including cardiac arrhythmia, coronary artery disease, and congestive heart failure, should always consult their physician prior to using sauna for the first time or before using it habitually, Dr. Lee said.
Effects compounded by exercise
Dr. Minson stressed that any type of heat therapy should be part of a lifestyle that includes mostly healthy habits overall, especially a regular exercise regime when possible.
“You have to have everything else working as well: finding time to relax, not being overly stressed, staying hydrated – all those things are critical with any exercise training and heat therapy program,” he said.
Dr. Lee said it’s easy to overhype the benefits of sauna bathing and agreed the practice should be used in tandem with other therapies, not as a replacement. So far, stacking research has shown it to be an effective extension of aerobic exercise.
A June 2023 review published in Mayo Clinic Proceedings found that while sauna bathing can produce benefits on its own, a post-workout sauna can extend the benefits of exercise. As a result, the researchers concluded, saunas likely provide the most benefit when combined with aerobic and strength training.
While some of the benefits of exercise overlap those associated with sauna bathing, “you’re going to get some benefits with exercise that you’re never going to get with sauna,” Dr. Ganio said.
For instance, strength training or aerobic exercise usually results in muscle contractions, which sauna bathing does not produce.
If a person is impaired in a way that makes exercise difficult, taking a sauna after aerobic activity can extend the cardiovascular benefits of the workout, even if muscle-building does not occur, Dr. Lee said.
“All other things considered, especially with aerobic exercise, it is very comparable, so we can look at adding sauna bathing post exercise as a way to lengthen the aerobic exercise workout,” he said. “It’s not to the same degree, but you can get many of the ranging benefits of exercising simply by going into the sauna.”
The authors have disclosed no relevant financial relationships.
A version of this article originally appeared on Medscape.com.