Why We Turn Up the Heat: The Science Behind Infrared Fitness

If you've never worked out in an infrared-heated studio before, you might be wondering:

Is there actually a benefit to working out in the heat or do we just really like to sweat?

Here at LŪMA, heat isn't added just for the sake of making your workout feel harder. Our studio was designed around the combination of infrared heat and infrared light to create a workout experience that feels different from the moment you walk into the room. And there's some pretty interesting science behind it.

First, What Exactly Is Infrared?

Infrared is a form of electromagnetic energy that exists just beyond the visible spectrum of light. Unlike conventional heating systems that primarily heat the air around you, infrared energy can transfer heat directly to the body and surrounding surfaces. Researchers typically divide infrared into near-, mid-, and far-infrared wavelengths, and different wavelengths interact with the body differently. That's important because infrared isn't one single therapy and not every benefit  you've heard about "infrared" applies to every type of infrared exposure.

So what do we know?

1. Heat Increases Circulation

When your body gets warm, blood vessels near the skin dilate and blood flow increases as your body works to release heat. Your heart also has to work harder to maintain circulation and regulate body temperature. That's one reason your heart rate may increase during a heated workout even when the movements themselves are relatively low impact.

Research into far-infrared exposure has also explored its effects on vascular and endothelial function, including mechanisms involving nitric oxide, which helps regulate blood vessel dilation. For your workout, that means you're combining the circulatory demands of exercise with your body's natural response to heat.

2. Warm Muscles Tend to Move Differently

There's a reason athletes warm up before training. Increasing tissue and muscle temperature changes some of the mechanical properties of muscle and can make movement feel more comfortable. That's one of our favorite parts of infrared fitness. 

Instead of spending the first portion of class feeling stiff and waiting for your body to "wake up," the warm environment helps create conditions that allow you to settle into movement, mobility, and range of motion. And if you've ever walked into a LŪMA class feeling stiff and walked out feeling completely different, you already know the feeling we're talking about.

3. Your Cardiovascular System Gets an Added Challenge

One of the reasons a heated workout can feel so effective is that your body is also working to regulate its temperature. As your body warms, your heart rate naturally rises and blood flow increases to both your working muscles and your skin. This creates an added cardiovascular demand, even during movements that are intentionally low impact. The result? 

You can challenge your strength, endurance, and cardiovascular system at the same time without needing every workout to be filled with running or high-impact movement.

And researchers are increasingly interested in what repeated heat exposure may mean for cardiovascular health beyond a single workout. In one landmark Finnish study, researchers followed more than 2,300 men for approximately 20 years (y’all.. that’s actual long term data!) and found that frequent sauna use was associated with significantly lower rates of cardiovascular and all-cause mortality. Those who used a sauna four to seven times per week had a 50% lower risk of fatal cardiovascular disease compared with those who used a sauna once per week. While a traditional Finnish sauna isn't the exact same as an infrared fitness class, findings like these have sparked growing interest in how repeated heat exposure supports cardiovascular health over time.

4. Infrared Is Being Studied for Muscle Performance + Recovery

This is where the research gets especially interesting.

A 2025 systematic review and meta-analysis examined 21 randomized controlled trials using near-infrared light before exercise. Researchers found evidence that near-infrared exposure may help reduce the decline in muscle strength following exercise and may influence markers associated with muscle damage and soreness.

Other research specifically examining far-infrared therapy after strenuous eccentric exercise has found improvements in recovery of muscle strength and reductions in muscle soreness compared with sham treatment. The research gives us exciting insight into how infrared light interacts with muscle tissue, circulation, and recovery.

5. Heat Creates Its Own Physiological Adaptation

Here's something we love about the human body: it adapts to what you consistently ask it to do. Repeated exercise in warm environments can lead to what researchers call heat acclimation, which is where physiological changes occur to help your body become more efficient at handling heat. With repeated exposure, your body can improve its ability to regulate temperature and sweat efficiently while adapting its cardiovascular response to the added demands of a warm environment. In other words, that first heated class may feel very different from your tenth.

Researchers are also beginning to look at what happens when exercise and repeated heat exposure are combined. In one randomized controlled trial, participants who combined regular exercise with sauna bathing experienced greater improvements in cardiorespiratory fitness and systolic blood pressure than those who exercised alone.

It's an exciting area of research because it suggests that heat may be more than something your body simply tolerates during a workout. It may be another stimulus your body learns to adapt to alongside the movement itself.

Over time, you may start noticing that you feel more comfortable in the heat, recover your breathing more quickly, and feel more capable of handling the challenge. Your body isn't just getting through the heat. It's learning how to handle it more efficiently. And we think there's something pretty empowering about watching yourself become capable of something that once felt hard.

6. Yes, You're Going to Sweat

That LŪMA glow isn't just because you crushed your workout. As your body heats up during exercise, blood flow to the skin increases as part of your body's natural cooling response. Research has also shown that exercise-induced sweating can temporarily increase hydration in the outermost layer of the skin.

And here's one of our favorite sweat facts: your sweat actually contains antimicrobial peptides that are part of your skin's natural defense system. One of these, called dermcidin, is produced by your sweat glands and helps support the skin's innate defense against certain microorganisms.

Regular exercise has also been associated with improvements in skin circulation and may help support healthy skin function over time. So yes, the sweat has a purpose. It helps regulate your temperature, supports your skin's natural environment, and is part of the physiological response that gives you that unmistakable post-workout flush.

Consider the LŪMA glow a very welcome side effect. 

7. The LŪMA Effect

There are plenty of physiological reasons we love infrared, the increased circulation, warm muscles, cardiovascular challenge, and that incredible sweat, but the reason our members keep coming back is often much simpler: 

We are awesome. 

JK!... maybe 😛

They love how they feel when they leave.

Interestingly, research examining recovery after sauna exposure has found a shift toward greater parasympathetic activity, the "rest and recover" side of your nervous system, during the cool-down period. The study measured HRV following sauna and found increased vagal/parasympathetic indicators during recovery.

There's something about stepping into the warmth, turning down the lights, turning up the music, and giving yourself 50 minutes to focus on nothing but movement. You work hard. You get stronger. You sweat. And somewhere along the way, the stress of the day starts to feel a little quieter. Then the movement slows down, the cold towels come out, and you get that I really needed that feeling.

Every time you come back, you start to notice the little wins. You go a little deeper. Hold a little longer. Pulse a little slower. Pick up the heavier weight. You realize you're capable of more than you were the last time, and it feels GOOD to keep showing up for yourself. 

 LŪMA was built around the belief that movement should be something you want to come back to. And a great workout should leave you feeling better than when you walked in.

That's the LŪMA effect.

Ready to Feel It for Yourself?

You can read about infrared all day, but there's really only one way to understand why our members love it. Your first class (or 100th class) doesn't have to be perfect. You don't have to already be "in shape." You don't need to know what you're doing, and you definitely don't have to keep up with the person next to you.

Just show up. We'll take it from there. ;)

Want to Nerd Out With Us? Here's the Research.

1. Laukkanen T, Khan H, Zaccardi F, Laukkanen JA. “Association Between Sauna Bathing and Fatal Cardiovascular and All-Cause Mortality Events.” JAMA Internal Medicine. 2015;175(4):542–548. doi:10.1001/jamainternmed.2014.8187.

2. Lee E, Kolunsarka I, Kostensalo J, et al. “Effects of Regular Sauna Bathing in Conjunction With Exercise on Cardiovascular Function: A Multi-Arm, Randomized Controlled Trial.” American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 2022;323(3):R289–R299. doi:10.1152/ajpregu.00076.2022.

3. Peng P, Zheng X, Wang Y, et al. “The Effects of Near-Infrared Phototherapy Preirradiation on Lower-Limb Muscle Strength and Injury After Exercise: A Systematic Review and Meta-analysis.” Archives of Physical Medicine and Rehabilitation. 2025;106(1):74–90. doi:10.1016/j.apmr.2024.04.013.

4. Chen TC, Huang YC, Chou TY, Hsu ST, Chen MY, Nosaka K. “Effects of Far-Infrared Radiation Lamp Therapy on Recovery From Muscle Damage Induced by Eccentric Exercise.” European Journal of Sport Science. 2023;23(8):1638–1646. doi:10.1080/17461391.2023.2185163.

5. Bontemps B, Gruet M, Vercruyssen F, Louis J. “Utilisation of Far Infrared-Emitting Garments for Optimising Performance and Recovery in Sport: Real Potential or New Fad? A Systematic Review.” PLOS ONE. 2021;16(5):e0251282. doi:10.1371/journal.pone.0251282.

6. Ahokas EK, Hennessy RS, Hanstock HG, Kyröläinen H, Ihalainen JK. “Effects of Post-Exercise Heat Exposure on Acute Recovery and Training-Induced Performance Adaptations: A Systematic Review.” Sports Medicine – Open. 2025;11:106. doi:10.1186/s40798-025-00910-0.

7. Laukkanen T, Lipponen J, Kunutsor SK, et al. “Recovery From Sauna Bathing Favorably Modulates Cardiac Autonomic Nervous System.” Complementary Therapies in Medicine. 2019;45:190–197. doi:10.1016/j.ctim.2019.06.011.

8. Wang S, Zhang G, Meng H, Li L. “Effect of Exercise-Induced Sweating on Facial Sebum, Stratum Corneum Hydration, and Skin Surface pH in Normal Population.” Skin Research and Technology. 2013;19(1):e312–e317. doi:10.1111/j.1600-0846.2012.00645.x.

9. Schittek B, Hipfel R, Sauer B, et al. “Dermcidin: A Novel Human Antibiotic Peptide Secreted by Sweat Glands.” Nature Immunology. 2001;2:1133–1137. doi:10.1038/ni732.