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Story at-a-glance

• Training in infrared saunas is a growing trend among athletes and health seekers, combining movement with radiant heat to boost performance and improve recovery in less time
• Infrared light is divided into near-, mid-, and far-infrared wavelengths, each with different biological effects
• Near-infrared light penetrates deeply into your tissue and activates photobiomodulation, a mitochondrial process that boosts ATP production, nitric oxide release, and cellular repair
• Most commercial saunas rely on far-infrared or weak near-infrared LEDs, which only offer surface-level warmth without sufficient irradiance to stimulate healing
• To get real training benefits from infrared, choose a near-infrared sauna. You can build one at home using red-filtered incandescent bulbs for safe, high-irradiance, full-spectrum therapeutic exposure

You train to feel stronger, think more clearly, and stay healthy over the long haul. Whether it’s lifting weights, logging miles, stretching, or riding hard, the goal is to keep showing up and to make every effort count. What if there’s a way to support your body more fully while you move? That’s exactly what happens when you combine exercise with infrared heat.

The practice has started gaining momentum, and for good reason. If you’ve followed my work, you know I’ve long emphasized the value of infrared therapy. That effect comes down to what infrared heat is actually used, how it interacts with your body, and why some forms work better than others for performance and recovery.

What Is Infrared Heat and How Does It Affect Your Body?

Infrared light sits just beyond the visible red end of the spectrum. It’s a form of light you can’t see, but you can feel it as warmth. It’s divided into three categories based on wavelength — near-infrared, mid-infrared, and far-infrared. Each behaves differently in the body, and those differences matter when it comes to how infrared is used in training and recovery.

• Near-infrared has the shortest wavelength and penetrates most deeply — About 40% of the sunlight spectrum is near-infrared. It penetrates up to 4 inches into tissue, reaching muscle, blood vessels, and even the mitochondria inside your cells, where it delivers its strongest effect by influencing how energy is produced and how cells repair themselves after stress.

• Near-infrared goes a step further — It activates a process called photobiomodulation, which stimulates the cytochrome c oxidase located in the mitochondria. When this enzyme absorbs light in the right range, it plays a role in increased adenosine triphosphate (ATP) production (the cell’s main energy currency).1

At the same time, this interaction prompts the release of nitric oxide, increasing mitochondrial respiration and blood flow. This shift supports circulation, tissue oxygenation, and energy availability, which are valuable factors in physical performance and recovery.2

• Mid-infrared sits between near- and far-infrared — It reaches slightly deeper than far-infrared but does not engage mitochondrial pathways the way near-infrared does. Its contribution is primarily gentle warming below the skin’s surface.

• Far-infrared has the longest wavelengths and lowest energy — Most of its activity stays near the surface of the skin. It raises temperature and promotes sweating, which is useful for relaxation and fluid elimination, but it doesn’t penetrate deeply or interact with the body at a cellular level. Its effects are primarily thermal rather than metabolic, which limits its role in stimulating adaptation during exercise. Despite this poorer effect, the vast majority of infrared saunas are far-infrared.

Once you understand how different wavelengths behave in the body, the next step is seeing what they unlock when used in motion. Exercising in infrared heat doesn’t just feel more intense; it changes how your body adapts, grows, and recovers.

How Infrared Heat Strengthens the Way You Train

Training in a heated environment changes how the body responds to effort. When you exercise inside an infrared sauna, you’re placing your system under both mechanical and thermal stress. Over time, that added input enhances the effects of your workouts in the following ways:

• Improved endurance and cardiovascular performance — Training in infrared heat raises your body’s core temperature and prompts a cardiovascular response that mirrors aerobic exercise. Oxygen transport improves and cardiovascular strain is reduced as your body adapts.

These changes support a lower resting heart rate and more efficient thermoregulation during physical effort. Over time, this translates to measurable improvements in VO2 max and a longer time to exhaustion during training.3,4

• Enhanced strength and muscle growth — Infrared heat activates cellular stress signals that reinforce muscle-building pathways. This includes the stimulation of heat shock proteins and mTOR, both of which play a role in tissue repair and hypertrophy.5 Thermal exposure also promotes the release of growth hormone, prolactin, noradrenaline, and beta-endorphins, which influence performance, motivation, and recovery.6

• Faster recovery and less inflammation — Infrared heat supports recovery by triggering cellular repair pathways and easing the inflammatory load that follows hard training. It increases blood flow to damaged tissues, helping clear waste products like lactate and inflammatory cytokines while delivering the oxygen and nutrients needed for regeneration.

Moreover, heat exposure stimulates the release of heat shock proteins, which stabilize stressed cells and help repair microscopic muscle damage, reducing soreness and speeding your return to full capacity.7

• Detoxification and immune support — The detoxifying effect is amplified when you sweat while exercising in the sauna, combining the deep thermal release of passive heat with the metabolic activation of movement. This passive release places less burden on the cardiovascular system while still stimulating detox pathways.8,9

Near-infrared light also supports immune balance by activating mitochondrial signaling inside immune cells, which helps modulate inflammatory responses and maintain terrain stability.10

• Weight loss support — Infrared heat increases metabolic rate, which contributes to greater calorie burn during and after each session. Research also shows that a single infrared sauna session elevates energy expenditure comparable to moderate-intensity exercise.11

• Relaxation and stress relief — The warmth of the infrared sauna helps ease muscular tension and activate the parasympathetic nervous system. As core temperature rises, cortisol levels begin to drop, allowing the body to shift into a more restorative state. Combined with the stillness of the environment, this promotes deep relaxation, steadier mood, and improved stress resilience between workouts.12

The benefits of sauna training go well beyond physical gains — read “Are Saunas Good for Your Brain?” to learn how it also benefits your cognitive health.

What You Need to Know About Commercial Saunas

If you’re aiming to get all the benefits of infrared-enhanced training, the type of equipment you use matters just as much as the effort you put in. Many infrared saunas on the market are designed around far-infrared emitters, which means their effects are largely thermal, but they fall short of delivering what your body actually needs.

• Some manufacturers blur these distinctions — Devices built around far-infrared are often marketed using the benefits of near-infrared, even if they deliver only trace amounts of it, or none at all. Others promote “full-spectrum” systems, but their near-infrared components are typically low-irradiance LEDs or modified heating elements that don’t provide the tissue-level intensity required to activate real photobiological effects.

Irradiance refers to the power delivered over a given surface area, measured in milliwatts per square centimeter (mW/cm2). In short, it determines how much light your body actually absorbs and whether a light source is strong enough to activate photobiomodulation.

• Another issue is electromagnetic fields (EMFs) — Many infrared systems labeled as “low-EMF” still emit high levels of electric fields, even if magnetic fields are suppressed. These electric fields activate stress responses and interfere with nervous system balance, especially when used regularly. Most consumers don’t have the tools to measure this kind of exposure, and companies rarely disclose it.

To avoid all of this, the most reliable option remains the high-irradiance incandescent near-infrared sauna. These use natural-spectrum bulbs that emit both therapeutic light and gentle radiant heat, without generating high EMF exposure.

Why Incandescent Heating Is an Ideal Choice

Once you understand how important wavelength and irradiance are, the next question becomes — What kind of light source actually delivers them? That’s where incandescent near-infrared light stands apart.

• Natural-spectrum incandescent light delivers full-spectrum benefits — Unlike narrow-band LEDs, incandescent bulbs emit a wide, continuous spectrum of light that includes the therapeutic wavelengths often filtered out by more energy-efficient options. The same wavelengths that regulators once dismissed as “waste heat” are exactly the ones your mitochondria rely on to trigger repair.

• Incandescent sauna is a century-old therapy — The concept of incandescent sauna therapy dates back over 100 years, with origins in the early 20th-century sanitariums of Dr. John Harvey Kellogg. Today, this approach is still accessible. Whether you purchase a professionally shielded system or build your own, the therapeutic effect is the same.

All you need is an enclosed space that holds ambient temperatures above 100°F and a light-safe fixture that protects you from direct bulb contact. Even a converted closet or shower stall works.

• Traditional bulb setups deliver physiologically relevant light dose — The standard for this kind of setup is a 250-watt red-filtered incandescent bulb, used in a configuration of four. At about 24 inches away, this delivers 30 mW/cm2, closely mimicking the near-infrared irradiance we get from sunlight.

A 20- to 30-minute near-infrared sauna session in this setup delivers around 36 to 54 J, which is right within the recommended photobiomodulation range.

• Scalable, localized use for targeted issues — If you’re not ready to commit to a full-body sauna, a single incandescent bulb can be used for localized therapy. This targeted approach has been used for headaches, muscle knots, neuropathy, and stubborn skin problems. Over time, many people expand to full setups after experiencing firsthand the impact of focused near-infrared on pain, circulation, and recovery.

If your goal is to move, heal, and rebuild with infrared, it makes sense to use the form of light that aligns with how the body works. To learn more about how to use a near-infrared sauna or how to properly build your own using incandescent bulbs, read “Repairs DNA and Rejuvenates Your Cells While You Relax.”

Tips for Staying Safe While Training in Infrared Heat

If you’re planning to incorporate this method into your workout routine, it pays to be smart about it. Infrared training is powerful, but like any form of stress, it works best when applied wisely. These safety practices help you stay comfortable and avoid overexertion:

• Start slow and stay hydrated — Begin with shorter sessions and lower intensity. As your body adapts to the heat, you can gradually increase duration and effort. Make sure to drink water before, during, and after your session. Add electrolytes if you’re sweating heavily or exercising for extended periods.

• Watch for warning signs — Dizziness, nausea, headache, or excessive fatigue are signs you need to cool down and rest. Step out and allow your body to recover.

• Keep sessions under control — Most people benefit from 20 to 30 minutes of infrared training. More time isn’t necessarily better. Pushing past your limits in the heat could delay recovery.

• Rotate your body if using lamps — If you’re using an incandescent sauna or lamp setup, avoid staying in one position too long. Rotating helps ensure even exposure and reduces the risk of skin irritation or overheating.

Frequently Asked Questions (FAQs) About Infrared Heat Training

Q: What is infrared heat training?

A: Infrared heat training is the practice of pairing exercise with infrared heat exposure, usually by working out in a space warmed by near-infrared light like a sauna.

Q: Can I exercise inside an infrared sauna?

A: Yes. Training inside an infrared sauna combines physical and thermal stress, amplifying cardiovascular, muscular, and metabolic responses. This pairing improves VO2 max, speeds recovery, and helps regulate stress hormones more efficiently than training alone.

Q: Why is near-infrared better for performance and recovery?

A: Near-infrared light activates a process called photobiomodulation, which boosts ATP production, increases nitric oxide release, and improves blood flow and oxygenation. These effects accelerate tissue repair, reduce inflammation, and support energy availability, which are important factors for athletic recovery and training adaptation.

Q: Are all infrared saunas the same?

A: No. Most commercial saunas use far-infrared only, which does not penetrate deeply or stimulate mitochondrial repair. Some claim to be “full-spectrum,” but often deliver inadequate near-infrared intensity. Only incandescent saunas offer high-irradiance light that mimics sunlight and activates true healing responses.

Q: Can I build my own near-infrared sauna?

A: Yes. You can set up your own incandescent near-infrared sauna using four 250-watt red-filtered bulbs, a safe enclosure, and basic heat shielding. This setup replicates the same irradiance as sunlight and delivers optimal photobiomodulation.

Sources and References

• 1 Journal of Translational Medicine Volume 21, Article number: 135 (2023)
• 2 FASEB J. 2022 Sep;36(9):e22490
• 3, 7 Int J Environ Res Public Health. 2021 Jan 27;18(3):1105
• 4 Am J Physiol Regul Integr Comp Physiol. 2022 Jul 4;323(3):R289-R299
• 5 Front. Sports Act. Living 7:1462901
• 6 Current Opinion in Endocrine and Metabolic Research Volume 11, April 2020, Pages 15-20
• 8 Galen Med J. 2020 Dec 25;9:e2003
• 9 Int J Environ Res Public Health. 2022 Apr 4;19(7):4323
• 10 Biology (Basel). 2022 Dec 29;12(1):60
• 11 Science Daily, June 12, 2019
• 12 PLoS One. 2023 Nov 27;18(11):e0294137