Blood pressure doesn’t drop during a sauna

Contrary to the previous assumption, blood pressure does not drop during a sauna session – it rises. And this increase is even comparable to the increase caused by a short, moderate workout. This is one of the conclusions of a recent study carried out by sports scientists at the Martin Luther University Halle-Wittenberg (MLU) in collaboration with the Medical Center Berlin (MCB). On separate days, the participants were sent to a sauna and placed on a bicycle ergometer. In addition to higher blood pressure levels, an increase in heart rate was measured both during the sauna visit and during exercise. The study was recently published in the international journal Complementary Therapies in Medicine.

It is generally assumed that a sauna visit leads to a continuous fall in blood pressure. “It was thought that the heat dilates the blood vessels and that this lowers the blood pressure”, says Dr Sascha Ketelhut, lead author of the new study and a sports scientist at MLU. People with low blood pressure or cardiovascular disorders have traditionally been advised not to use saunas, as a further fall in blood pressure can lead to fainting. “However, it is important to distinguish between the acute effects of a sauna session and the effects that were noted during the rest period after the sauna session. Many previous assumptions have been made about the acute effects of sauna use, but so far little research has been done”, continues Ketelhut.

The scientists conducted their study by recruiting 19 volunteers to measure the immediate effects of sauna use on the cardiovascular system: The participants were exposed to a 25-minute sauna session, while having their blood pressure and heart rate measured. Both rose immediately during the sauna visit. After the sauna session, both blood pressure and heart rate began to drop below participant’s baseline levels that were measured before the sauna session.

Source: Sweating for science: A sauna session is just as exhausting as moderate exercise