My gym’s recovery fitness options include a sauna, a cold plunge and a hot tub. The sauna easily gets the most play. Sometimes there are so many people in there that hopefuls are forced to wait outside, shivering in their swimwear. The cold plunge is also really popular, but on a rotational basis. People tend to pop in for two minutes or so, often monitoring their process via a clock on the wall, as if performing a plank, then swap out.
Weirdly, the hot tub is often empty, or receives only a cursory few minutes from those with any interest in it. It’s not due to lack of space — it’s large enough to fit seven people, compared to the cold plunge’s three. What’s going on? Who doesn’t love a jacuzzi?
My theory is simple: at a hard-charging gym like mine (hint: it starts with an “E”!), hot tubs don’t currently hold the same cultural cachet as saunas and cold plunges. But they should — and that may soon change.
Recovery Bias
Podcasters, celebrities and fledgling studios have certainly spread the good word on saunas and cold plunges over the last five years.
They’ve done such a great job, I’d argue, that the actual science of these practices has ceased to matter. As multiple experts outlined for me in my exploration of “contrast therapy” last year, cycling between hot and cold probably isn’t the home run that wellness influencers are promising. Updated knowledge on the issue has trickled into the mainstream over the last year or so.
We now know that saunas don’t really “flush toxins” from the body, while cold plunges trigger a “cascading inflammatory response,” which may reduce muscle growth. So why does it seem like people don’t really care?
The Gospel of Contrast Bathing
Sauna, ice bath, repeat. Here’s how the wellness world got obsessed with cycling between hot and cold.It’s possible that the sustained popularity of saunas and cold plunges has morphed into a social phenomenon. These amenities have become an extension of the performances that occur on the gym floor. Trainees bear extreme temperatures and track their best times; they growl when someone lets a millisecond of outside air into the sauna, grit their teeth when a competitor joins them in the ice bath. Conversely, kicking back in a hot tub feels tame — and in certain settings, maybe even a little embarrassing.
Not that I think this is some massive societal scourge. Hot tubs aren’t that deep (literally or figuratively). Still, the topic is a fascinating on-ramp for probing today’s optimization culture, particularly because hot tubs do seem to be pretty effective for recovery fitness.
New Research on Hot Baths
Yes, the ultimate irony is true. Research published last December in Medicine & Science in Sports & Exercise concluded: “In athletic contexts where a rapid force development is a key performance determinant, hot bath should be preferred over cold bath.”
While small, with just 30 men involved, the study assessed muscle strength, pain levels and muscle activity after hard bouts of exercise, against a variety of different recovery methods.
Performance expert Michael Easter (who sat for an interview with InsideHook earlier this year) covered the study in his Substack: “The hot bath but not the cold one improved recovery of explosive strength and led to reduced muscle soreness. The catch is that you can’t just dip in and dip out…once your body gets warm enough, it produces more heat shock proteins, which help cellular repair.”
How long? Easter says 20 minutes, though medical experts recommend a 15-minute max in hot tubs. In the spirit of de-optimizing our recovery fitness routines, I’d lightly suggest not timing your session. Just stay in there a while — long enough that your muscles (and brain) feel relaxed, not so long that you start resembling a desiccated cicada.
Do You. Just Don’t Overdo It.
I’m not suggesting you abandon cold plunges or saunas. Personally, I’m sticking with both. I like ice baths because they make me feel alive. They’re a nice shock to the system. And I make time for saunas when they’re empty; I like to put my feet up and stretch my tight runner hips. Both arenas are also great for practicing breathwork.
Ultimately, it helps to remember what you’re trying to accomplish. If you’re a professional athlete with lofty goals, you likely already rely on a team of experts. If you’re literally anyone else, your routine should leave room for joy and relaxation — which happen to be potent recovery methods in their own right!
Here’s the key takeaway: sitting in a hot tub isn’t difficult. It’s actually quite pleasant, and that’s perfectly okay. Take a well-earned break from the sufferfest. This is your chance to cash in on some recovery benefits without having to try so damn hard.
Meet your guide
More Like This
The Charge will help you move better, think clearer and stay in the game longer. Subscribe to our wellness newsletter today.
