Infrared Sauna for Muscle Recovery: New Science Says 110°F Is All You Need

New data on infrared saunas suggests you don’t need to scorch your eyebrows to recover like an athlete.

Let’s get one thing straight immediately: heat is the hero here, not the heater. We tend to fetishize the equipment—the cedar wood, the fancy panels, the app-controlled humidifiers—but the biology is surprisingly indifferent to your brand loyalty. If you can get your body temperature up, good things happen. Whether you are baking in a traditional Finnish torture chamber or basking in the gentle glow of a modern infrared box, the goal is therapeutic heat exposure. The delivery system is just a detail.

I went through a heavy phase last fall where I basically lived in a traditional hot rock sauna. I’m talking thirty days straight. I was sweating out demons I didn’t know I had. After that sprint, I dialed it back to a consistent three days a week, and I felt fantastic. But lately, I’ve started looking for something different. I’ve been reading up on the custom red light infrared units from SaunaCloud, and since I’m already chemically dependent on my red light therapy routine, combining the two feels like a natural evolution.

The skepticism feels natural, too. Every week there is a new “must-have” recovery protocol. But a 2023 study out of Finland (where else?) dropped some fascinating data that validates the gentler, light-based approach to sweating it out.

“The infrared sauna session attenuated the decrease in countermovement jump performance... and muscle soreness was less severe.”

What’s the Big Idea?

Finnish scientists decided to torture some basketball players to see if glowing red lights actually do anything. The setup was simple but brutal: take sixteen male athletes, put them through a “complex resistance exercise protocol” (a nice way of saying they wrecked their legs with heavy squats and plyometric jumps), and then see what happens next.

Half the group sat in a room at normal temperature for 20 minutes. The other half sat in an infrared sauna (IRS) at 43°C (that’s about 109°F). Note that temperature—it’s significantly lower than the 170°F+ you see in traditional rock saunas.

Fourteen hours later, the researchers measured everything again. Here is what they found: the guys who just sat in the room saw their explosive power (measured by how high they could jump) tank significantly. Their legs were dead. The guys who hit the infrared sauna? Their power didn’t drop nearly as much. They maintained their snap.

Even better, the sauna group reported significantly less muscle soreness (DOMS). They felt ready to train again, whereas the passive group felt wrecked. The infrared radiation didn’t magically repair the muscle fibers—biomarkers for muscle damage like creatine kinase were the same in both groups—but it cleared the neural fog and pain perception enough to restore performance.

💡 In Plain English
Think of your post-workout muscles like a highway after a storm. The infrared heat didn't fix the potholes—the biological markers of muscle damage remained the same—but it cleared the debris and opened the lanes so traffic could move again. You regained your speed and flow not because the road was perfect, but because the congestion was gone.

Why It Matters and What You Can Do

You might assume that for heat to work, it has to hurt. The “no pain, no gain” mentality bleeds into recovery, leading us to believe we need to sit in 200°F heat until our ears burn to get a benefit. This study proves that idea wrong. A mere 20 minutes at ~110°F was enough to preserve neuromuscular function.

The infrared wavelengths (specifically IR-A, IR-B, and IR-C used in this study) penetrate deeper into the tissue than hot air (convection). This theoretically allows for increased peripheral blood flow and muscle temperature maintenance without the surface-level agony of a super-hot room.

Here is how to apply this to your routine:

• Don’t chase the high numbers: If you have access to an infrared sauna like the ones SaunaCloud builds, you don’t need to crank it to the max. The study used 43°C (110°F). If you are using a hot rock sauna, you might need higher air temps to get the same internal effect, but for IR, lower is fine.

• Timing is key: The athletes jumped in the sauna shortly after the workout. This isn’t effective if you wait two days. If you want to blunt the soreness manifest destiny, get in the box within the hour after lifting.

• Duration matters: They only stayed in for 20 minutes. You don’t need to do an endurance run in there. Get in, get warm, get out.

What’s Next on the Horizon

We are barely scratching the surface of why this works. The study showed that while perceived recovery and performance were better, the actual blood markers of muscle damage (creatine kinase and myoglobin) didn’t change between the groups. This implies the benefit might be neuromuscular or related to the clearance of metabolic waste products closer to the nerve endings, rather than structural repair of the muscle belly itself.

The crossover between red light therapy (photobiomodulation) and infrared heat is the next frontier. Since players in the space like SaunaCloud are combining these modalities, the question becomes: is it the heat or the light energy that matters? Infrared radiates heat, but it is also light. Future research needs to isolate these two variables. For now, we know the combination helps you jump higher the next day.

Safety, Ethics, and Caveats

Here is the catch regarding your nervous system. Sitting in a sauna is a stressor. The study found that during the 20-minute session, the athletes’ heart rates went up and their Heart Rate Variability (HRV) went down. The body went into “sympathetic” mode (fight or flight) to handle the heat load.

However—and this is the critical part for anyone worried about sleep—this stress was short-lived. By the time the athletes went to bed, their nocturnal HRV and sleep quality were identical to the group that didn’t sauna. There is a persistent myth that doing a sauna session in the evening will keep you awake because of the cortisol spike or body temp rise. These findings suggest that if you give yourself a cooldown buffer, your sleep won’t suffer.

Also, be real about the limitations. The study was small (16 people), and you can’t placebo-control a sauna. You know if you are hot or not. The “feeling” of recovery might be partly psychological, but in athletics, if you feel better, you generally perform better.

One Last Thing

If you have been obsessing over which specific wood-paneled box to buy, stop. The data says the heat works, the pain goes down, and your jump shot stays snappy. Just get in and sweat.

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Explore the Full Study

Ahokas, E. K., et al. (2023). A post-exercise infrared sauna session improves recovery of neuromuscular performance and muscle soreness after resistance exercise training. Biology of Sport. Read the full paper here.

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