What Sauna Does to Your Body — and Why Longevity Experts Swear by It
After testing cold plunges, I turned to sauna. Here's what sauna really does to your body, what the science says, and how it fits into the longevity lifestyle.
Hi, I'm Shantanu — I run a longevity-focused health brand based in Singapore. Most of my time is split between building digital-first platform, experimenting with performance tools, and writing weekly on what it means to build a high-performance life.
If you’ve been following this series, you know I tried cold plunging after my HYROX race in Bangkok. But what I didn’t share in that post: I also did sauna — before and after the plunge. It was my first proper contrast therapy experience.
Naturally, I had to dive into the science. And the deeper I looked, the clearer it became: sauna isn’t just a recovery trend. It’s one of the most powerful, accessible longevity tools we have today.
In a world obsessed with the newest surgeries and procedures, it’s easy to overlook simple, consistent lifestyle interventions. But if you ask me: fasting, sleep, and sauna do more for health span than most pills and therapies we throw money at. (And to be clear, I’m not anti-medical innovation. We need to fund new science — it just takes time.)
Today, we go deep into sauna science, explore what it really does to your body, and share how you can build it into your recovery and longevity routine — whether you’re in Singapore or traveling overseas.
Today’s Index
What Sauna Does to Your Body (Plain Science)
Recovery and High-Performance Health
Longevity & Hormesis
Who Should Try Sauna — And How to Start
Where to Try Sauna in Singapore — and At-Home Alternatives
Onsen vs Sauna — What’s the Difference?
1. What Sauna Does to Your Body (Plain Science)
Sauna works by exposing your body to high temperatures (typically 70–90°C). This creates a temporary, controlled form of stress called hormesis — the same kind of "good stress" we get from fasting, exercise, or cold exposure.
Key responses in the body:
Vasodilation: Blood vessels widen, improving circulation ( Cold therapy has opposite effect)
Heart rate rises: Mimics moderate exercise (like brisk walking)
Sweating intensifies: Helps eliminate waste products
Heat shock proteins (HSPs) increase: These protect and repair cellular function
Inflammatory markers drop: Over time, sauna use can lower CRP and other inflammation indicators
All of this supports recovery, cardiovascular function, and cellular health.
But wait — isn’t Singapore already hot and humid?
Fair question. Yes, we sweat outdoors here all the time. But passive sweating from humidity isn’t the same as structured heat exposure in a sauna.
In sauna:
Your core body temperature rises more significantly
You get sustained heart rate elevation, closer to cardio activity
The dry heat stimulates hormetic cellular responses not triggered by ambient weather
So yes, sweating in Singapore isn’t enough. Sauna is controlled, therapeutic heat stress — not just discomfort from walking outside.
2. Recovery and High-Performance Health
Sauna isn’t just relaxing. It has concrete physical benefits post-training:
Muscle soreness: Sauna promotes circulation and nutrient delivery to tired muscles
Lactic acid: Heat accelerates removal of metabolic waste
Sleep quality: Many users (myself included) report deeper sleep after sauna use
One study showed that athletes who used sauna post-training had faster recovery of strength and less soreness 24–48 hours after workouts.
And personally? I bounced back shockingly fast after HYROX. Between the cold plunge and sauna, I felt clearer, stronger, and more motivated than after any previous race.
3. Longevity & Hormesis
This is where sauna really shines.
Frequent sauna use has been linked to longer life expectancy, especially in the Finnish cohort studies led by Dr. Jari Laukkanen. Key findings:
4–7 sauna sessions per week were linked to 60% lower risk of all-cause mortality
65% lower risk of Alzheimer’s disease in frequent users
Improved cardiovascular health, lower blood pressure, and improved endothelial function
Mechanisms:
Heat shock proteins (HSPs) activate repair and protect damaged cells
Improved insulin sensitivity and reduced oxidative stress
Better autonomic nervous system regulation
These aren’t minor effects. Sauna, used consistently, may act as a metabolic and neurological reset — supporting both heart and brain.
What about beyond Finland? Good question. While most studies originate from Nordic countries, recent papers from other regions support similar findings:
A 2021 study in Environmental Health and Preventive Medicine (Japan) found regular sauna bathing improved mood and reduced fatigue in middle-aged adults.
A 2020 randomized controlled trial in Complementary Therapies in Clinical Practice (Germany) showed sauna use significantly lowered blood pressure in hypertensive patients.
A 2019 study from New Zealand, published in Temperature, confirmed cardiovascular and autonomic nervous system benefits in a non-Finnish population using infrared sauna.
In summary:
Finland leads with decades of robust cohort data showing mortality, cardiovascular, and brain health benefits.
Japan has shown sauna-style therapies can improve chronic disease symptoms in clinical settings.
Southeast Asia lacks research — but that doesn’t mean sauna isn’t beneficial here. If anything, it’s a great candidate for more studies.
4. Who Should Try Sauna — And How to Start
Sauna isn't only for elite athletes or biohackers. Based on the evidence, it benefits:
Longevity-focused adults — Especially 40s–60s looking to age better
High-performance professionals — For mental reset, recovery from desk fatigue
Recreational athletes — To recover faster and train better
People feeling 'stuck' — A simple weekly ritual to restore energy
Start slow: Begin with 10–15 minutes, 2–3 times per week. Work your way to 20-minute sessions if comfortable.
Avoid sauna:
After alcohol
If dehydrated
If you have unstable cardiovascular conditions (always consult a doctor first)
5. Where to Try Sauna in Singapore — and At-Home Alternatives
In Singapore:
Soma Haus (Joo Chiat) – A full contrast therapy facility with sauna, cold plunge, and breathwork.
Yunomori Onsen & Spa (Kallang Wave Mall) – Japanese-style onsen with sauna options.
The Ice Bath Club (East Coast) – Offers guided cold and heat therapy sessions, often in community formats.
At-Home Alternatives: If you prefer home use or don’t have time to travel, devices like the Hydragun HeatPod simulate sauna-like benefits using infrared or conductive heat. While they may not hit the same high temperatures as traditional saunas, they can still:
Raise core body temperature
Promote recovery
Trigger relaxation and parasympathetic tone
These pods are gaining traction among urban professionals who want a convenient way to access heat therapy without the full spa setup.
6. Onsen vs Sauna — What’s the Difference?
Onsen: Hot mineral water, often outdoors. Promotes relaxation and skin benefits. Not as high in heat stress.
Sauna: Dry or infrared heat. Raises core temperature significantly. Stronger hormonal and cellular response.
Both are great — but for metabolic and recovery gains, sauna has the edge.
👋 Thanks for reading
If you made it this far — thank you. Whether you're chasing better recovery, cognitive clarity, or long-term health, sauna is one of the simplest tools to explore.
If you're based in Singapore and want to try a session, I’m happy to share a few free passes — just reply to this post or message me @shan.kr on Instagram.
Next week, we close the series with contrast therapy — the combined effect of cold plunge and sauna. Make sure to subscribe.
I write weekly on longevity, performance, and the hard parts of building a consumer business. Been at it for 2+ years. You can always catch up at outofsg.com.
And if this post helped you, share it with someone curious about high-performance health. Thanks for being here.
—Shan