‘Japanese sauna’ can improve sleep — and may burn 600 calories

It’s basically the dream — you lay down in a magic pod for a half-hour and come out younger, lighter and a lot more relaxed.

That’s the promise behind the Iyashi Dôme, a “Japanese sauna” that the makers say can reduce wrinkles, improve sleep, hydrate skin, promote muscle recovery and even help you lose weight.

But under all the sweating — and I mean sweating — can 30 minutes infrared therapy do all that? I put it to the test (and even checked what my Oura ring had to say about the effects).

If you’ve ever visited a Japanese sento — or bathhouse — you may have spent some time schvitzing in the sauna. But you may not have seen anything like the Iyashi Dôme.

That’s because there are only about 800 of them in the world, mostly in high-end hotels in Paris and Dubai. And there are just two in New York City, both inside Manhattan’s Reforme spa.

Unlike the sauna you may be thinking of, where you sit on wooden benches in a hot, dry room, this is a single-person bed with a dome on top that uses infrared radiation to heat up your body.

So why just lay there and sweat? Infrared saunas — and saunas and general — have been linked to a ton of health benefits, including better heart health, blood pressure, sleep and relaxation. They can also soothe sore muscles and ease pain, boost lung function and immunity, and may even lower your risk of dementia.

As for the Iyashi Dôme, the company says it’s both slimming and anti-aging — and one 30-min Iyashi Dôme session is equivalent to a roughly 12-mile run, getting rid of 40 ounces of sweat and 600 calories.

Does the Iyashi Dôme Japanese sauna work?

When I tried the dome at Reforme, which charges $150 per session, I immediately noticed two clear plusses over a traditional sauna.

First, because you’re inside the dome, you can go totally naked with complete privacy. Second, you’re not sitting uncomfortably on a wooden bench, but laying down on a cushioned, towel-covered bed.

“It wasn’t until I woke up that I realized how much the sauna had actually done for me.”

I started on my stomach for 15 minutes, getting cozy enough that I thought I could drift off. By the time the tech had me flip onto my back, I was starting to sweat.

That second 15 minutes was when I really felt changes. For one, I got drenched. Just one big puddle of sweat.

My heart rate was also elevated — I could feel it beating hard and fast, which is perfectly normal for a sauna but not something I’d noticed in one before. I think because you’re laying still in this one with few distractions, it’s easier to be in tune with what your body is doing.

Even though my face was entirely outside the domed area, it got red and sweaty, too.

By the end of my 30 minutes, I was somehow feeling both gross and great, kind of like after a tough workout — but also significantly more relaxed.

I headed home around 7 p.m. and wanted to go to bed for the night. I managed to hold off until a more reasonable time, and it wasn’t until the next morning that I realized how much the sauna had actually done for me.

After waking up, I checked my stats on my Oura ring, which tracks things like sleep time, sleep quality, resting heart rate and stress levels.

My “readiness score” — a calculation that predicts how well your body will deal with exertion that day — had jumped to 86, up 12 points from the day before.

My sleep score was also great, at 91 — not the highest I’ve ever had, but up there.

The real improvement was my restfulness, which is based on how often I woke up or moved during the night. I’ve been steadily getting “fair” here, the only sleep metric that hasn’t been great for me. Last night, it was “good” for the first time.

The graph of my sleep stages throughout the night showed why — I’d had way fewer wake-ups than usual, nearly all after sunrise (that’s on me, I don’t have blackout curtains).

My resting heart rate even got to the lowest number it’s been since I started using the ring.

The proof’s in the wearable here: I was obviously able to de-stress, recover and get a fabulous night’s sleep more than I would on a normal day.

But did I actually lose 600 calories? Couldn’t tell you, my scale’s not that precise.

Would I do it again? Absolutely — between how relaxed I was after and how “ready” I felt the next morning, I’d go back once a week if I could (and just make sure to hydrate super well before and after).