Sauna for Longevity, Healthspan, and Recovery

In the endless stream of new biohacks, technology, and gadgets, it's challenging to decipher what can move the needle in healthspan and lifespan.

Saunas' popularity has exploded in recent years, and for good reason.

In today's newsletter, we will unpack the mechanisms and benefits of heat therapy, the optimal frequency/dosage, and real-world takeaways.

Disclaimer: This newsletter is intended for informational and educational purposes only and does not constitute medical advice. Sauna therapy can be dangerous if not performed properly and may not be safe for all individuals. Always consult a qualified healthcare professional before starting sauna therapy or making changes to your health routine, particularly if you have cardiovascular disease, blood pressure disorders, or other medical conditions.
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How Hot? How Long? How Often?

We will dig into the data shortly, but let's start with the optimal temperature, session duration, and frequency.

Optimal temperature? 176-194°F (80-90°C)

The first question we get after answering the optimal temperature is, "What about infrared saunas?" Most infrared saunas on the market don't reach the optimal temperature range. That said, there are suggestive benefits to infrareds, but they may require significantly more time in the sauna.

We replaced our infrared sauna with a ​traditional Finnish Sisu Sauna​ two years ago and couldn't be happier.

Two important points to highlight: First, there is an upper temperature limit of around 205-210°F, beyond which adverse symptoms appear, and benefits decline. Second, sauna and heat therapy do temporarily reduce spermatogenesis; to combat this, bring in an ice pack for your groin.

How long per session? 10-20 minutes

Each session is truly its own challenge. I find that my work-related stress, overall fatigue, and hydration all affect my tolerance and experience in the sauna. Some days are easier than others.

How many sessions per week? 4-7 sessions per week

Like an exercise program, consistency compounds with frequency.
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The Benefits, Mechanisms, and Data

Why choose to sit voluntarily in a sauna heated to 176-194°F? The benefits can be quite impressive.

​This large Finnish cohort study​ with a median follow-up of 20.7 years found that increased frequency (4-7 times per week) reduced sudden cardiac death risk by 63%, fatal coronary heart disease by 48%, fatal cardiovascular disease by 50%, and all-cause mortality by 40%.

​This 2022 randomized control trial ​took 47 sedentary individuals and randomized them into three groups: exercise, exercise + sauna, and control (no intervention). The study found that the exercise + sauna group showed greater improvements in cardiorespiratory fitness, lower systolic blood pressure, and lower total cholesterol than the exercise-only group.

Finally, ​this comprehensive​​, peer-reviewed article​ includes observational, interventional, and experimental studies that reinforce cardiovascular benefits and emphasize a reduced risk of neurocognitive impairment.

Note: the strongest evidence for sauna therapy comes from traditional Finnish saunas, based on cohort studies and small intervention studies. Further research is needed to solidify causation and outcomes.

Why do we see these benefits from frequent sauna and heat therapy?

1. Mimics a response similar to moderate exercise. Heat increases peripheral vasodilation, raising your heart rate and cardiac output, decreasing arterial stiffness, and improving endothelial function.
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2. Release of heat shock proteins (HSPs). The controlled hyperthermia you experience in the sauna tells your body to release heat shock proteins. HSPs help prevent proteins from misfolding, refold damaged proteins, and protect mitochondria.
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3. Autonomic and neuroendocrine effects. During a sauna session, the sympathetic system (fight-or-flight) is activated, but afterward, the parasympathetic system (rest-and-digest) is activated and amplified. This improved parasympathetic tone is associated with better mood, lower anxiety, and improved sleep quality. I can assure you that after a day of work, exercise, and a sauna session, my sleep is noticeably better.

The Takeaway: Sauna is a Piece of The Puzzle

Hopefully, after today's newsletter, you now have a better understanding of the data and benefits of sauna therapy.

I want to stress that heat therapy is one piece of the puzzle. It's been a phenomenal addition to my exercise and wellness routine, but not the sole activity.

If sauna therapy is something you're interested in, start small and increase your time or temperature as your tolerance builds.

Two suggestions before a sauna session:

1. A sauna hat. Not for looks but for functionality. A sauna hat helps reduce the temperature around your head, improving endurance and enjoyment in the sauna.
2. Hydration. You can easily lose 1 to 5 pounds of water weight in a sauna session. To avoid dehydration, start drinking water early in the day and consider adding electrolytes to replace the sodium, magnesium, and potassium lost during the session. There's nothing worse than waking up in the middle of the night with a punishing calf cramp.

Sauna sessions can be a great way to spend time alone, with friends and family, or to add an extra challenge to a workout.

Find what works best for you.
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Stay Hydrated the Right Way

Hydration isn’t just about drinking more water — it’s about replacing what you lose.

When you sweat (from workouts, sauna sessions, or just daily life activities), you’re not just losing water — you’re losing electrolytes like sodium, potassium, and magnesium.

That's why I drink ​​LMNT​ as my electrolyte replacement.

LMNT uses a science-backed electrolyte ratio of sodium, potassium, and magnesium.

Electrolytes are used by every cell in your body. Even minimal dehydration can limit cognitive and physical performance.

LMNT tastes great and helps me replenish my electrolytes after a hard workout or sauna. I mix one LMNT packet (usually ​Grapefruit Salt​, my favorite flavor) into a 32-oz water bottle to stay hydrated throughout the day.

If you want to try LMNT for yourself, ​click here to receive a FREE sample pack of all 8 flavors with any purchase, plus a No Questions Asked Refund Policy.​

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Only the best,

Jeremy London, MD

P.S. Don't forget to follow my podcast for free on ​Spotify​ or ​Apple Podcasts

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