But is a post-workout steam really worth the extra time spent at the gym? And what is the sweaty, steamy ritual even supposed to do?
Here, top exercise physiologists and heat stress researchers answer all of your questions.
What’s a steam room, anyway?
A room with steam in it—duh. But, really, a steam room is any room that’s warmed to roughly 110 to 115 degrees Fahrenheit and has humidity levels at or near 100 percent, says Jason Machowsky, R.D., C.S.S.D., C.S.C.S., an exercise physiologist at the Hospital for Special Surgery in New York City. Usually, an electrical generator along with special plumbing is to thank for the hot, sticky climate. You’ll find water dripping down the walls, coating the seats (usually benches), and on the floor (don’t slip!). Fortunately, because they are so darn humid, steam rooms are constructed of water-proof materials and designed so that water can run down a drain, rather than pooling everywhere.
So, wait. What’s the difference between steam rooms and saunas?
Steam rooms and saunas differ in two main ways: degree of heat and humidity, says Jari Laukkanen, M.D., Ph.D., University of Eastern Finland researcher. As warm as steam rooms sound, saunas are ridiculously hotter—often up to 160 to 200 degrees Fahrenheit. However, they are a lot less humid. Saunas give off a dry heat, with humidity levels around 5 to 20 percent. Wood-burning saunas are the most traditional version, but electrical and gas versions also exist. Saunas using infrared technology are another big trend.
The low humidity levels are what allow saunas to get so much hotter than steam rooms. After all, if you heated water up to 200 degrees and threw it all over your body, it would cause some pretty intense burns, says Mike T. Nelson, Ph.D., C.S.C.S., a Minnesota-based exercise physiologist.
He also explains that the additional moisture and humidity of the steam room thwarts the body’s ability to effectively cool itself. While there’s no data comparing steam room vs. sauna sweat rates, we know that in humid environments, sweat isn’t able to evaporate as easily as in drier environments. It’s this evaporation that allows the body to regulate body temperature. For that reason, cranking steam-room temps to sauna levels could result in not only burns, but also heat illness, Machowsky says.
Are there any real benefits to hitting the steam room after exercise?
Steam room-lovers claim that getting hot and humid after a workout helps to jumpstart exercise recovery, cleanse the body of toxins, improve immunity, and basically check off a laundry list of awesomeness.
The thing is, steam rooms haven’t really been studied enough to say if any of the benefits are true or false. “There’s not even squat out there on direct data regarding steam rooms,” Nelson says.
For example, while a 2012 Medical Science Monitor study is often cited as showing steam room benefits for post-workout recovery, the study actually looked at combining steam rooms and whole-body vibration therapy to increase blood flow to the skin. “If the study were to look at muscle blood flow, and without vibration therapy, maybe,” Nelson says. “But skin blood flow with vibration therapy? That’s a stretch.” Plus, the study was small (10 people) and only looked at a specific population (older adults).
RELATED: How Do Foam Rollers Work?
That said, a respectable number of studies exist on saunas, many of them from Finnish researchers and centered around cardiovascular effects. (In Finland, sauna bathing is a common activity.) For example, Laukkanen and his team’s recent findings, published in the Journal of Human Hypertension, found that one 30-minute sauna session significantly lowered blood pressure in 102 people with at least one cardiovascular risk factor. What’s more, their carotid-femoral pulse wave velocity, an indicator of how well blood vessels expand and contract as needed, increased.
Laukkanen hypothesizes that improved arterial flexibility and dilation reduces the amount of force that moving blood exerts on the blood vessel walls. He notes, however, that it’s possible that the lowered blood pressure findings could also be linked with heat’s axiality (science-speak for anxiety-reducing) outcomes—that is, just relaxing in a heated environment may be enough to affect your blood pressure levels.
“Hot environments are known to increase the body’s parasympathetic tone,” Nelson says. People are comparatively more relaxed in hot environments than in cold ones and, across cultures and centuries, beaches, saunas, steam rooms, and hot springs have been used as places to get some R&R. “That’s not a coincidence,” he says.
Some studies have looked at whether post-exercise heat therapy could impact exercise recovery, but, again, these studies have limitations like a small sample size and specific population. In one 2015 Springerplus study, for example, researchers found that both traditional and infrared saunas improved exercise recovery in 10 physically active men who used saunas regularly.
However, as Laukkanen notes, any possible post-exercise benefit has only been studied in saunas, not steam rooms. And, so far, there’s no definitive word on if hitting the steam room after exercise spurs similar effects. Hypothetically, they could—but likely only if they increase internal body temperature to the same degree as saunas. “The temperature might be too low,” he says.
Are there any risks to sitting in a steam room?
Even if the alleged benefits of sitting in a steam room after exercise haven’t been proven, there’s not a ton of downsides. For most people who are generally healthy, the biggest risks are dehydration and dizziness. But the solution is pretty simple there: hydrate and, if the heat starts to go to your head, just get out, Nelson says.
RELATED: Does Cryotherapy Really Promote Muscle Recovery?
However, it is advised that you talk to your doctor before using a steam room after exercise if you have any health conditions such as asthma (the steam could make breathing a bit more complicated) or heart disease. Also, if you are pregnant or are planning to become pregnant, it’s best to lay off any whole-body heat therapy, steam rooms included.
It’s also worth mentioning that bacteria, mold, and other ickies thrive in hot, humid environments. “Poor sanitation can create issues with mold or germ transfer,” Machowsky says. But as long as your gym is on top of its steam-room cleaning routine, you should be good. (If you’re concerned, you can always ask management or the cleaning staff how and how often the steam room gets a good wash-down.)
Here’s how to use a steam room at the gym.
Steams are best left for after workouts (rather than before), when you can benefit most from some relaxation, Nelson says.
Before stepping in, proper steam-room etiquette is to shower off (it helps cut down on that germ issue), and then to wear your birthday suit but cover up with a towel. Make sure that you are sitting on the towel when you’re in there (think about it!) and consider your own comfort and everyone else’s in there before opening up the front of your towel for all of the steam room to see.
During your first few sessions, start small. At your gym, you might not be able to adjust the thermostat, but you can adjust how much time you choose to spend in there, Nelson says, recommending that people start with 5 or 10 minutes and increase to 30 as it feels good to you.
When you’re in there, make the most of your time by meditating, practicing mindfulness, or performing breath work, he says. Or, if you’re in there with friends, go ahead and talk it up; social time has plenty of mental and physical benefits, and it’s completely acceptable to have a measured conversation while in a steam room. Just make sure to feel out the vibe first and be courteous—if everyone else is sitting there with their eyes closed, they are probably going to be bothered by loud chatting.
In the end, just do you, and stay off of your phone (unplugging is good, and the humidity could hurt your phone anyway). The goal is to leave the steam room feeling better than when you walked in.