Michael Mosley in a hot bath

This month the BBC’s award-winning documentary maker and science journalist, Dr. Mike Mosley, took part in an experiment to test the benefits of heat therapy versus exercise. The experiment was prompted by a 2015 medical study in Finland which showed that regular sauna usage can not only improve your cardiovascular health but also reduce the risk of associated cardiovascular diseases and even extend your overall lifespan. Mike put together a group of volunteers to test out the theory for the 2016 Summer special of ‘Trust me I’m a Doctor’ on BBC2.

The programme found that the body’s energy expenditure increase by 80% during the experiment, which as you might expect equates to calories burnt. In fact, the average participant burnt 140 calories per hour, the equivalent of a brisk 30-minute walk!

Perhaps more surprisingly was the effect that the heat therapy had on the subject’s blood sugar levels. The peak blood sugar in the test subjects was 10% lower after the heat therapy then than it was after a corresponding amount of exercise. So although more calories were burned on the treadmill, the effect that the heat therapy had on glucose levels was more beneficial than the effect of the exercise, this is relevant as prolonged high peaks in blood sugar increase the risk of illnesses such as type two diabetes.

Mike believes this is because the heat therapy keeps the muscles more consistently at a higher temperature than during exercise. This leads to as a greater amount of heat shock proteins being released into the blood which in turn helps to remove sugars from the bloodstream and absorbs them within the muscle.

Compared with an hour spent cycling or on a treadmill, I know which part of the experiment I’d rather be doing!

Read the full BBC Magazine article here or catch-up with the ‘Trust Me I’m A Doctor’ Summer Special 2016 on the BBC IPlayer.