How to burn off the calories ... have a soak in a (very) hot bath

A LoNG soak in the bath may not seem like the best way to get fit.

But lying in a piping hot tub burns as many calories as a 30-minute walk, scientists have discovered.

An hour in 40C water burns off 140 calories and lowers blood sugar even more than exercise.

It follows earlier studies which found that men who frequently use saunas cut their risk of heart attack and stroke.

researchers at Loughborough University found that steaming in a bath may, like exercise, produce the ‘heat shock’ proteins thought to remove sugar from the blood stream and transport it to the muscle cells where it is burned as fuel.

their study of 14 men could provide a new way to ward off high blood pressure among those who fail to go for a walk as often as they should. It is published in the journal temperature and lead author Dr Steve Faulkner has written about the findings on website the Conversation.

he said: ‘many cultures swear by the benefits of a hot bath. But only recently has science began to understand how passive heating improves health.

‘Activities that increase heat shock proteins may help to improve blood sugar control. these activities, such as soaking in a hot tub or taking a sauna, may have health benefits for people who are unable to exercise regularly.’

he added: ‘People were asking why would sitting in a bath cause people to burn energy. I think it might be down to the way in which the body is trying to regulate its temperature and that energy is spent trying to keep cool, just as when someone is cold there is an energy cost from their muscles shivering to keep them warm.’

his team recruited 14 men who were either thin or overweight, to raise their body temperature by 1C either by soaking in a hot bath or cycling for an hour.

Unsurprisingly, an hour of cycling burned more calories than a bath, but the tub saw people lose 140 calories – about the same as a half-hour walk.

And their blood sugar was about 10 per cent lower at its peak after eating than if they had exercised.

the baths in the study had water circulating to keep them stable at 40C, but it is thought household baths could have a similar effect if the temperature can be maintained.