Train, then sweat: the trial that put sauna on top of exercise

There is a lazy version of the sauna story: sit in the heat and skip the gym.

The research does not support it. What it does support is more useful.

The trial

In 2022, researchers at the University of Jyväskylä ran an eight-week randomised controlled trial. The results were published in the American Journal of Physiology.

They recruited 47 adults, average age 49. All had low activity levels and at least one cardiovascular risk factor, such as raised blood pressure or cholesterol.

Participants were randomly assigned to one of three groups:

• Guideline-based exercise, followed by a 15-minute sauna
• The same exercise, without sauna
• A control group that changed nothing

What they found

Compared with exercise alone, the exercise plus sauna group saw a greater gain in cardiorespiratory fitness, a larger fall in systolic blood pressure of about 8 mmHg, and lower total cholesterol.

Eight millimetres of mercury is a meaningful difference in blood pressure terms, and it came on top of what the exercise already did.

It fits the long-term picture

Finnish cohort research has also looked at fitness and sauna habits together in the same men, followed over decades, and reported the combination alongside lower mortality risk.

That is observational data, so it cannot prove cause. But the trial and the cohort point in the same direction: fitness and heat seem to work together.

How to use this

• Train first. The exercise is the foundation.
• Follow with around 15 minutes of sauna, which matches what the trial used.
• Rehydrate properly, and cool down gently before standing up fast.
• If you take blood pressure medication, check with your GP first. Heat plus those medicines can make you light-headed.

This is how we think about the Stillhet Kube in a home. Not as a replacement for the session, but as the fifteen minutes that follow it.

Free: The Norge Longevity Guide. Heat, cold and light after 50, with the evidence and the safety rules in one place. Get the guide.

Sources

1. Lee et al., Effects of regular sauna bathing in conjunction with exercise on cardiovascular function: a multi-arm randomized controlled trial, 2022
2. Kunutsor et al., Joint associations of sauna bathing and cardiorespiratory fitness on cardiovascular and all-cause mortality risk, 2018

This article is general information, not medical advice. If you have a heart condition, low blood pressure or are pregnant, speak with your GP before using heat or cold.