Sauna after a workout: what an eight-week trial added
Inactive adults were assigned to exercise, exercise plus 15 minutes of sauna, or neither. Adding the sauna went with lower blood pressure and better fitness than exercise alone.
The short version
Researchers in Finland randomly assigned 47 inactive adults with at least one heart risk factor to three groups for eight weeks: exercise three times a week, the same exercise followed by 15 minutes in a sauna, or no change. Exercise alone improved fitness. Adding the sauna went with a further gain in fitness, systolic blood pressure about 8 points lower and lower cholesterol than exercise alone. It is one small, short trial, and a later look at the same people found no added benefit for heart rate variability.
Keep in mind
One small trial, 47 people over eight weeks. There was no sauna-only group, so it tests sauna added to exercise, not sauna instead of it.
What they found
Compared with no change, exercise alone improved fitness by 6.2 mL/kg/min and reduced fat mass, but did not change blood pressure.
Compared with exercise alone, exercise plus sauna improved fitness by a further 2.7 mL/kg/min (95% confidence interval 0.2 to 5.3), lowered systolic blood pressure by 8.0 mmHg (1.4 to 14.6) and lowered total cholesterol.
A later analysis of 38 of the same participants, published in 2025, found that adding sauna did not improve heart rate variability beyond what exercise did.
What this means for your practice
This is an early sign that a sauna after exercise may add something to what training does for blood pressure and fitness. It needs a larger trial before anyone can count on it.
This does not establish a sauna routine to follow, and it says nothing about sauna in place of exercise.
Methods and limitations
What the researchers did
The researchers recruited 47 adults, on average 49 years old, who were physically inactive and had at least one heart risk factor, such as high blood pressure or high cholesterol.
People were randomly assigned to one of three groups for eight weeks: guideline-based exercise three times a week, the same exercise followed each time by 15 minutes in a sauna, or no change to their routine.
The sauna started at 65°C and was raised by 5°C every two weeks. Blood pressure and fitness (peak oxygen uptake) were the main measures; fat mass, cholesterol and artery stiffness were also measured.
How much can this tell us?
Random assignment makes this stronger evidence of cause and effect than the long Finnish observation studies. The sauna was an ordinary Finnish sauna, used much as people use one after a workout.
It is small. With about 15 people per group, the ranges are wide: the extra fitness gain could be close to nothing, and the blood pressure difference could be as small as about 1 point.
Eight weeks says nothing about years. And because there was no sauna-only group, the trial cannot say what sauna does without exercise.
What makes it useful
- Randomized, with an exercise-only group for comparison
- An ordinary Finnish sauna after ordinary workouts
- Blood pressure and fitness measured directly
What limits it
- Small: 47 people, about 15 per group
- Short: eight weeks
- No sauna-only group
- People knew which group they were in
Where this study fits
Where this study fits
We score claims, not single studies. This one is part of the evidence for:
A few weeks of regular heat lowers blood pressure. Some support
Low certaintySmall effectBody signals
Sauna after a workout adds to what training does. Some support
Low certaintyMedium effectBody signals
Read the original
Lee E, Kolunsarka I, Kostensalo J, Ahtiainen JP, Haapala EA, Willeit P, Kunutsor SK, Laukkanen JA. Effects of regular sauna bathing in conjunction with exercise on cardiovascular function: a multi-arm, randomized controlled trial. Am J Physiol Regul Integr Comp Physiol. 2022;323(3):R289-R299.
DOI 10.1152/ajpregu.00076.2022 · PubMed 35785965