Can saunas make you live longer? - Max G. Levy

In the early 1980s, a group of scientists set out to conduct a long-term study

on heart health.

They focused on Finnish men, recruiting over 2,000 participants

and monitoring everything from their behaviors, diets,

lifestyle choices, and fitness over the course of 20 years.

As they dug into the data,

researchers were stunned to find that one habit—

something they hadn’t expected— was linked to better health:

frequent sauna bathing.

Yet this likely didn’t surprise the Finnish participants.

Finland is a country with 9,000 years of sauna traditions.

And they’re not alone:

Roman balneae, Japanese onsen, and Indigenous American sweat lodges

are just a few examples of how cultures across the globe

have long considered exposure to extreme temperatures therapeutic.

But today, scientists are only just beginning to unravel how and why

this may be the case.

So, what exactly is happening in your body when you feel the heat?

To understand how extreme heat affects the body,

let’s explore what happens when you enter a sauna.

Traditional Finnish sauna temperatures can top out at 90°C,

or just below the boiling point of water,

and are typically dry, at about 20% humidity.

This blast of dry heat ignites your thermoregulatory response.

Specialized temperature-detecting proteins in the skin change shape,

triggering sensory neurons to send this high heat message to the brain.

Blood vessels widen, and your heart rate ticks up to circulate blood faster.

To shield your vital organs from intolerable temperatures,

your skin absorbs heat, creeping up to 41°C,

and dumps this heat from your body's surface.

You sweat.

If this response reminds you of exercise, that’s no coincidence.

Physiologists who study sauna use have likened the body's heat response

to a moderate workout.

And while time in the sauna isn't a replacement for exercise,

regular exposure to controlled heat may stress the heart and, over time,

strengthen the cardiovascular system in similar ways.

Heat may also complement exercise and help aid recovery.

In strenuous workouts, muscle fibers acquire microtears.