Overall, sauna and exercise both cause an increase in heart rate, blood pressure, sweat rate, and blood flow to skeletal muscle and skin. Exercise definitely increases respiratory rate, and sauna sometimes does the same. Additionally, they are similar in their long-term benefits, improving blood pressure, endothelial function, and arterial stiffness.[1][2]
At the time of creation of this page, there are two studies that have directly compared exercise and sauna:
A 2019 study in 19 healthy participants compared a 25-minute session in a traditional Finnish sauna at 93°±3°C and 13%–20% relative humidity to a 6-minute session on a stationary bicycle ergometer (starting at 50 watts and increasing by 10 W every minute to a maximum of 100 W).[3] Interestingly, despite interventions with very different durations, the outcomes measured followed very similar trends and reached almost identical final values: systolic and diastolic blood pressure increased by about 15 mmHg in both groups; heart rate increased by about 43 and 53 bpm in the exercise and sauna group, respectively; and the product of systolic blood pressure and heart rate (a correlate of cardiac oxygen consumption) increased by 107% — which was similar to the increase observed during exercise. Similar to exercise, blood pressure dropped below presauna levels within 30 minutes of the end of the sauna bath.
A 2022 crossover study in 10 healthy women compared moderate-intensity exercise (heart rate between 55% and 70% of maximal heart rate) on a stationary bike, infrared sauna at 60°C (140℉) and less than 20% relative humidity, and resting at approximately 25°C (77℉) , with each intervention applied in three 15-minute intervals separated by 5 minutes of rest at 25°C (77℉).[4] This trial found that tympanic temperature (a proxy of core temperature) was significantly higher in the sauna group and that respiratory rate was significantly higher in the exercise group. Interestingly, heart rate, blood pressure, mean arterial pressure, heart rate variability, and transient arterial stiffness did not differ between the sauna and exercise groups. There are many reasons for these unremarkable findings, but it’s possible that neither intervention was sufficiently physiologically stressful to meaningfully distinguish it from the control condition.
Overall, it seems that sauna can provoke cardiovascular responses that are similar to exercise, although the specifics of the sauna intervention matter a lot. It’s also important to note that, unlike exercise, sauna does not actively engage skeletal muscles and therefore wouldn’t be expected to cause improvements in muscle mass, muscle strength, or muscle endurance unless paired with an exercise training program.
References
- ^Nguyen Y, Naseer N, Frishman WHSauna as a therapeutic option for cardiovascular disease.Cardiol Rev.(2004)
- ^ Farrell & TurgeonNormal Versus Chronic Adaptations To Aerobic Exercise(2022)
- ^Ketelhut S, Ketelhut RGThe blood pressure and heart rate during sauna bath correspond to cardiac responses during submaximal dynamic exercise.Complement Ther Med.(2019-Jun)
- ^Joy N Hussain, Marc M Cohen, Nitin Mantri, Cindy J O'Malley, Ronda F GreavesInfrared sauna as exercise-mimetic? Physiological responses to infrared sauna vs exercise in healthy women: A randomized controlled crossover trialComplement Ther Med.(2022 Mar)