The Science of Sauna: More than just Heat

Ancient Practice Meets Modern Science

Using heat for healing is not a new practice.  Across cultures, humans have turned to heat for thousands of years.  From the origins of the dug-out pit saunas of ancient Finland to Native American sweat lodges, Russian banyas, Middle Eastern hammams, and the temazcal traditions of Central America, heat has long been a global tool for bathing, healing, ceremonial rituals and spiritual practices.   

In modern times, saunas have often been associated with spas, gyms, or luxury retreats.  But in recent years, especially here in the UK -  that’s started to shift.  Saunas are now popping up by the sea, lakes, on farms, and in urban spaces, becoming more accessible to more people.  In 2021 the British Sauna Society was formalised to support the growing sauna community in the UK.  While most know sauna for its post-workout recovery and relaxing effects, we’re only just beginning to understand its deeper impact.  Sauna isn’t just about sweating - it activates systems in the body that support long-term health, build resilience, and may even promote longevity.

Thanks to the pioneering work of Dr. Jari Laukkanen and Dr. Setor Kunutsor, sauna has moved beyond a wellness trend and into the spotlight of preventative medicine and longevity.  Their research shows that regular sauna use may lower the risk of chronic diseases, support mental wellbeing, and even help extend lifespan.

Let’s explore what the science actually says and why sauna might just be the simplest health practice you’re overlooking.

Science-Backed Benefits of Sauna

Cardiovascular Health

Cardiovascular diseases remain the leading cause of death worldwide, making any practice with proven heart benefits worth exploring.  Sauna use has been shown to mimic the effects of moderate to high-intensity aerobic exercise.  During a sauna session, heart rate increases, blood pressure temporarily increases, and vasodilation (widening of blood vessels) occurs.

In a 2024 review by Laukkanen & Kunutsor, frequent sauna use (4–7 times per week) was linked to a significantly reduced risk of:

• Cardiovascular disease

• Stroke

• Hypertension

• Sudden cardiac death

These benefits likely come from improved blood flow, reduced inflammation and a more balanced nervous system - all important for lifelong heart health.  A 2022 MONICA Study in Northern Sweden found significantly lower rates of high blood pressure among people who used the sauna regularly, even just 1- 4 times per month.

Mood and Happiness

Mental wellbeing may be one of the most underappreciated benefits of sauna use.  Sauna induces deliberate stress to the body - triggering the release of mood-boosting neurotransmitters like norepinephrine and endorphins.  This mild, short-term stress helps build long-term stress resilience.

Findings from the MONICA Study in Northern Sweden showed that even sauna use as infrequently as once per month was associated with greater happiness, energy, and mental clarity.

Sauna also shows potential for:

• Supporting emotional regulation by rebalancing the nervous system

• Reducing symptoms of anxiety and depression

• Increasing parasympathetic (rest-and-digest) activity

In fact, regular sauna users had up to a 65% lower risk of developing Alzheimer’s disease and a 66% lower risk of dementia, according to recent research.

Pain Relief and Inflammation Reduction

Sauna therapy has been shown to be effective in reducing both physical pain and inflammation.

A regular sauna practice can support conditions like:

• Chronic back pain

• Fibromyalgia

• Arthritis

• Muscle soreness post-exercise

These benefits likely stem from the increase in circulation, flushing of metabolic waste, and the rise in heat shock proteins, which assist in cellular repair and stress adaptation.

Sleep Quality

Sleep is another area where sauna has shown to support.  The body’s cooling response post-sauna mimics the natural drop in core body temperature required for sleep onset.  This encourages deeper, more restorative rest.

In the MONICA study, regular sauna users reported significantly higher satisfaction with their sleep.  These results support broader research showing that passive heat therapy especially before bed can increase deep sleep, the most restorative sleep phase.

How Much is Enough? (The Optimal Sauna Protocol)

What does the research say about how to sauna for best results?

Recommended Protocol

• Temperature: 60-100°C (typical Finnish sauna)

• Duration: 15-20 minutes per session

• Frequency: Research offers mixed recommendations on how often to use the sauna. Some studies suggest 3-7 times per week for the most benefit, while others show positive effects from as little as 1-4 sessions per month

• Rounds: 1-2 bouts per session, whilst combining sauna with exercise or contrast therapy (cold plunge) can amplify benefits

If you’re new to sauna:

• Start with shorter durations (10-12 minutes)

• Listen to your body

• Stay hydrated

• Consider combining sauna with cold exposure to enhance circulatory and nervous system benefits

The Hidden Power of Community

One of the less talked about but deeply powerful aspects of sauna is its role in community and social wellbeing.  In many cultures, sauna has always been a shared space and a place for connection and grounding.

The MONICA Study found that most participants preferred using the sauna with others.  This shared experience of sweating, resting, and sometimes plunging, offers more than conversation. It helps foster:

• A sense of belonging

• Emotional regulation through co-regulation

• Reduced isolation (a major driver of chronic stress and illness)

At Reyt Sauna, we see this every day.  Whether it is regulars catching up or first-timers stepping into the cold and heat together, the shared challenge and stillness create bonds. Sauna is not just a physical reset, but also a social practice that reminds us humans are social beings and are not meant to do life alone. In the sauna, we’re simply being. It’s a space where vulnerability feels safe, and like-minded people naturally connect.

Final Thoughts

Sauna is more than a trend, and it’s not just about heat. Sauna is a powerful, research-backed tool that supports the body, the brain, and even our communities. It taps into ancient cultures and modern science.  Regular sauna use has been shown to reduce the risk of cardiovascular diseases, dementia, alzheimer and support brain health and mental well-being.  All of which potentially extend our health span (how long you live in good health, not just how long you live).

It gives your nervous system a breather.  Your heart a workout. Your brain a lift. Your sleep a boost.  And your mood a reset.  In an overstimulated and noisy world, sauna invites us to pause and simply being.

Long before modern wellness trends brought infrared saunas to Instagram and spa menus, cultures around the world were already harnessing the power of heat.  Practices that are embedded in ancient cultures, in my opinion must carry some weight.  When humans have been doing something long before modern society existed, there’s usually a reason.

Often, the simplest practices are the most powerful: heat, cold, nature, moving your body, sleeping well, eating with the seasons, and being in community. These aren’t trends - they’re timeless tools for longevity, contentment, and peace.

Whether you come to recover, connect, or build resilience - you might leave with more than you expected.

Curious about how sauna and cold work together? Check out our first blog: Is Cold Water Dangerous? The Truth About Deliberate Cold Exposure

Come experience it for yourself at Reyt Sauna!  

Engstrom, A., Hagglund, H., Lee, E., Wennberg, M., Soderberg, S. & Andersson, M., 2024. Sauna bathing in Northern Sweden: Results from the MONICA study 2022. International Journal of Circumpolar Health, 83(1), Article 2419698.

Laukkanen, J.A. & Kunutsor, S.K., 2024. The multifaceted benefits of passive heat therapies for extending the healthspan: A comprehensive review with a focus on Finnish sauna. Temperature (Austin), 11(1), pp.27–51. doi:10.1080.

Laukkanen, J.A. & Kunutsor, S.K., 2023. Does the combination of Finnish sauna bathing and other lifestyle factors confer additional health benefits? A review of the evidence. Mayo Clinic Proceedings, 98(6), pp.915–926.