Saunas can be just as exhausting as a workout، research suggests.
A study found spending 25 minutes in a sauna raises a person's heart rate and blood pressure as much as a stint on a rowing machine، as the Daily Mail said.
These then fall once the sauna session is over، resulting in 'similar long-term positive effects to exercise'.
However، the researchers added saunas would not help people lose weight because there is no muscle activity involved. The research was carried out by Martin-Luther-University Halle-Wittenberg، Germany، and led by Dr Sascha Ketelhut، a sports scientist.
Many people assume saunas cause blood pressure to go down، the scientists wrote in the journal Complementary Therapies in Medicine.
'It was thought the heat dilates the blood vessels and that this lowers the blood pressure،' Dr Ketelhut said.
People with low blood pressure or heart conditions may even be advised to avoid saunas out of fear a further fall in pressure could make them faint. Many previous assumptions have been made about the acute effects of sauna use، but so far little research has been done،' Dr Ketelhut said.
To put this to the test، 19 healthy volunteers had their blood pressure and heart rates measured while they enjoyed a 25-minute sauna session.
Perhaps surprisingly، results revealed both their blood pressure and heart rates rose significantly and continuously while they sat in the sauna. Once out of the dry heat، both measurements dropped to levels below what they had been to start off with.
In a second part of the experiment، the volunteers completed a short stint on a rowing machine while having their blood pressure and heart rates measured.
'Comparing the two conditions، the participants' blood pressure and heart rate reached the same levels during the sauna session as they did with a load of about 100 watts during the exercise test،' Dr Ketelhut said.
Watts are a measurement of power output which is determined by a rower's resistance level and stroke rate.
If used regularly، saunas may lead to better heart health.
'A sauna session is a physical strain،' Dr Ketelhut said.
'Its long-term positive effects are similar to sports activities.'
And even those with low blood pressure should be able to enjoy a sauna every now and again.
'Saunas can actually be used by anyone who can tolerate moderate physical stress without discomfort،' Dr Ketelhut said.
'However، people with low blood pressure should be cautious afterwards، as their blood pressure may then fall below the levels registered before the sauna visit.'
The researchers also stress the sweating people experience while having a sauna will not help them lose weight.
'The effect is too low as there is no muscle activity،' Dr Ketelhut said. 'Although we lose weight in the sauna، these are just fluids we sweat out.'
To avoid dehydration، people should be sure to drink water when they get out of a sauna، he added.