The Sauna Effect: How Heat Therapy Supports Metabolic Health, Insulin Sensitivity & Longevity

What if you could give your body some of the benefits of exercise simply by raising your core temperature? Sauna therapy is gaining attention for its potential effects on circulation, cardiovascular health, glucose metabolism, and longevity; and you don’t need a traditional sauna to experience it! When most people think about a sauna, they probably think about relaxation, sweating, and maybe sore muscles after a workout. But there is something much more interesting happening beneath the surface.

When your body is exposed to heat, it has to work to maintain its internal temperature. Your heart rate rises, blood vessels dilate, blood flow increases, and your body activates a variety of cellular stress-response pathways. In other words, heat isn’t just something you feel, it is a physiological stressor that your body has to respond to. And that has caught the attention of researchers studying cardiovascular health, metabolic function, insulin sensitivity, and healthy aging.

What Happens to Your Body During Sauna Therapy?

When your body temperature rises, your cardiovascular system has to adapt. Your heart pumps faster to help move blood toward the skin, where heat can be dissipated. Blood vessels near the surface of the skin dilate, increasing circulation. You sweat to help cool yourself.

Research on sauna bathing and passive heat exposure has consistently documented acute increases in body temperature and heart rate, along with changes in blood pressure and vascular function. This is one reason sauna is sometimes described as a form of passive heat therapy. You’re not contracting your muscles or intentionally exercising, but your cardiovascular system is still responding to a significant physiological challenge. And that’s where things get interesting for metabolic health.

Heat Is a Form of Hormesis

One of the concepts I find fascinating about sauna therapy is hormesis. Hormesis refers to the idea that a small, controlled stress can stimulate adaptive responses that help the body become more resilient. Exercise is a classic example of this. You deliberately stress your muscles and cardiovascular system, and your body responds by adapting. Heat exposure may work through some of these same broad principles.

One important pathway involves heat shock proteins (HSPs). Heat shock proteins are produced in response to cellular stress and help protect and maintain proteins within cells. Research has linked heat shock proteins with pathways involved in oxidative stress, inflammation, metabolism, and insulin sensitivity. This doesn’t mean that sitting in a sauna is equivalent to doing a workout. It does mean that your body is responding to heat in a biologically active way.

Can Sauna Therapy Support Insulin Sensitivity?

This is one of the most exciting areas of research. Insulin resistance doesn’t happen overnight, and it isn’t reversed by one sauna session. However, researchers are investigating whether repeated passive heat exposure can influence glucose metabolism and insulin action.

In one human intervention study, 11 overweight but otherwise non-diabetic adults underwent 10 consecutive days of passive heat acclimation. Researchers found changes in glucose metabolism, including reduced basal and insulin-stimulated endogenous glucose production and greater insulin suppression of glucose production after the heat-acclimation period. That’s interesting. But it is also a very small study, and the intervention involved several hours of heat exposure per day—not a typical 20- or 30-minute sauna session. So the jury is still out on this area, but the research is promising.

Sauna and Cardiovascular Health

The cardiovascular effects of heat therapy are better established. When you enter a sauna, your heart rate can rise substantially as your body works to move blood toward the skin and dissipate heat. Repeated heat exposure may also influence vascular function and blood pressure.

A 2021 systematic review and meta-analysis of 15 studies found that heat therapy was associated with reductions in mean arterial, systolic, and diastolic blood pressure and improvements in flow-mediated dilation, a measure of vascular function. The researchers noted that the certainty of evidence varied and that more research is needed to determine the optimal type and dose of heat therapy.

More recently, a 2025 meta-analysis of 51 studies found that heat thermotherapy improved several acute and chronic cardiovascular measures, including reductions in blood pressure and improvements in some measures of vascular function. However, the researchers found no significant changes in several other markers, including C-reactive protein and heat shock proteins. This is important because cardiovascular health and metabolic health are deeply connected. Healthy blood vessels, good circulation, healthy blood pressure, and good insulin sensitivity all contribute to a body that is better equipped to handle metabolic stress.

What About Sauna and Longevity?

This is where sauna research gets especially fascinating. Some of the most well-known research comes from Finland, where sauna bathing is deeply ingrained in the culture.

In a prospective cohort study of 2,315 middle-aged Finnish men, researchers found that more frequent sauna bathing was associated with lower risks of sudden cardiac death, fatal cardiovascular disease, and all-cause mortality during more than 20 years of follow-up. Compared with men reporting one sauna session per week, those reporting four to seven sessions per week had substantially lower observed risks.

Another prospective cohort study included both men and women and found that cardiovascular mortality risk decreased as sauna frequency increased. And here’s an important detail: The research suggests that sauna and exercise may work beautifully together rather than being competing strategies.

In another long-term cohort study, both higher cardiorespiratory fitness and more frequent sauna bathing were independently associated with lower cardiovascular and all-cause mortality risk. The combination of high fitness and frequent sauna use was associated with the lowest observed risk.

Sauna Helps With Inflammation

Chronic, low-grade inflammation is another important piece of metabolic health. In a prospective Finnish cohort of more than 2,000 men, more frequent sauna bathing was associated with lower levels of C-reactive protein, a marker of systemic inflammation.

Another study following Finnish men for nearly three decades found that those reporting more frequent sauna bathing had lower all-cause mortality risk, even when researchers considered inflammation levels. Again, these findings are associations, not proof of causation. But they add another interesting piece to the puzzle.

Why I Think Heat Therapy Belongs in a Metabolic Health Routine

When I’m thinking about metabolic health, I don’t look for one magic intervention. I look at the big picture:

• Nutrition
• Strength training
• Movement
• Sleep
• Stress management
• Blood sugar regulation
• Healthy body composition
• Environment
• And recovery

Sauna therapy can complement several of those areas. It can challenge the cardiovascular system. It can increase circulation. It can promote sweating and relaxation. It can activate cellular stress-response pathways. And emerging research suggests it may influence metabolic pathways that are relevant to insulin sensitivity.

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Why I use Bon Charge Sauna Blanket

This is where the practicality comes in. I love the idea of sauna therapy, but having access to a traditional sauna isn’t realistic for everyone. You need the space. You need the installation. You need the time to get there. And most importantly, you need to actually use it consistently.

That’s why we love our BON CHARGE Infrared Sauna Blanket. The BON CHARGE Infrared Sauna Blanket uses far-infrared heat and allows you to adjust the temperature and session length. It reaches temperatures up to 176°F (80°C), has timer settings from 5–60 minutes, and is designed to fold away for convenient storage. For me, that convenience matters. I don’t always want to step outside to our Sauna, and we do not have the space for a traditional Sauna at our Keto Condo in Maui. This blanket gives all of the benefits of traditional Sauna without taking up the space or costing a hefty price.

How I Incorporate Sauna Therapy

If you’re new to sauna therapy, you don’t have to start with an intense session. Start conservatively and allow your body to acclimate to the heat. Don’t skip out on hydration and electrolytes, particularly because you’re losing fluid through sweating. And remember: more isn’t necessarily better. The goal isn’t to see how much heat you can tolerate. The goal is to create a sustainable routine that supports your overall health. Your sauna session should leave you feeling relaxed and refreshed, not depleted.

Sauna Therapy Isn’t a Replacement for Exercise

Let’s clear this up because the phrase “sauna is like exercise” can be misleading. Sauna can increase heart rate and place cardiovascular demands on the body, but it doesn’t provide the mechanical loading, muscle contractions, strength adaptations, or bone-loading benefits of resistance training and weight-bearing exercise.

Think of sauna therapy as something you can layer on top of other key foundations important for metabolic health that I outlined above. In fact, the research suggesting that physical fitness and sauna use may have complementary associations with long-term outcomes makes this combination particularly interesting.

Train Your Body to Handle Stress

We tend to think of stress as something we should eliminate. But your body actually needs some stress. The key is dose and recovery.

Exercise is a stress. Cold exposure is a stress. Heat exposure is a stress.

The goal isn’t to avoid every stressor. It’s to give your body manageable challenges that it can adapt to, and then give it the resources it needs to recover. This isn’t a replacement for a healthy diet or exercise. And the research doesn’t yet justify claiming that sauna therapy can reverse insulin resistance or guarantee longevity. But the growing body of research suggests that controlled heat exposure can meaningfully affect cardiovascular physiology and may influence several pathways connected to metabolic health and healthy aging.

And with an at-home option like the BON CHARGE Infrared Sauna Blanket, adding heat therapy to your routine becomes much more practical. Sometimes improving your health isn’t about finding one more thing to add to your already overwhelming to-do list. It’s about finding simple tools that make healthy habits easier to repeat.

A Note on Safety

Sauna and heat therapy aren’t appropriate for everyone. Heat exposure can cause dehydration, dizziness, changes in blood pressure, and other adverse effects, particularly at higher temperatures or with prolonged exposure. If you have a cardiovascular condition, are pregnant, take medications that affect blood pressure or fluid balance, or have another medical condition that could affect your response to heat, talk with your healthcare professional before beginning sauna therapy. Always follow the manufacturer’s instructions and stop if you feel unwell.

WHERE TO GET YOUR BON CHARGE SAUNA BLANKET

Once we found out my husband Craig had Lyme Disease, we needed to take action! He went undiagnosed for 5 years and he was suffering terribly!

I personally didn’t want to get a sauna, but Craig convinced me it would help him and he showed me all the research on why I should be doing it too!

We do not have a lot of space at our Keto Condo in Maui so a sauna blanket was perfect for getting all the benefits without taking up space!

Bon Charge is so generous when you use code MARIA, you get 20% OFF!

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Click HERE to get a Sauna Blanket so you can experience the benefits yourself! 

 

References & Further Reading

• • Laukkanen T, Khan H, Zaccardi F, Laukkanen JA. Association between sauna bathing and fatal cardiovascular and all-cause mortality events. JAMA Internal Medicine. 2015.
  • Laukkanen T, et al. Sauna bathing is associated with reduced cardiovascular mortality and improves risk prediction in men and women. 2018.
  • Pizzey FK, et al. The effect of heat therapy on blood pressure and peripheral vascular function: A systematic review and meta-analysis. Experimental Physiology. 2021.
  • Hussain J, Cohen M. Clinical Effects of Regular Dry Sauna Bathing: A Systematic Review. 2018.
  • Liu J, et al. Heat exposure and cardiovascular health outcomes: a systematic review and meta-analysis. Lancet Planetary Health. 2022.
  • Hooper PL, et al. Passive exposure to heat improves glucose metabolism in overweight humans. 2020.
  • Price BS, et al. Heat thermotherapy to improve cardiovascular function and cardiometabolic health: A systematic review and meta-analysis. Experimental Physiology. 2025.
  • Non-acute effects of passive heating interventions on cardiometabolic risk and vascular health: systematic review and meta-analysis of randomized controlled trials. 2025.