It has long been hailed as the cheat’s way to  exercise – while having fun.

And now Canadian researchers claim to have  discovered exactly how many calories the average person burns during  sex.

They say that in young people, sex burns an average of 4.2 calories a minute for men  and 3.1 calories a minute for women.

Sexercise? The average man burns 4.2 calories a minute  having sex, while women burn 3.1 calories. This makes it better exercise than a  walk – but not as good as jogging, say Canadian researchers

With the average session lasting 24.7  minutes, this equates to 104 calories for men and 69 for women.

This makes it better exercise than a walk –  but not as good as jogging.

The researchers, from the University  of Quebec at Montreal,  looked at  21 heterosexual couples aged between 18  to 35.

The average recorded session lasted for 24.7 minutes –  the shortest being 10 and the longest 57 minutes

During four sex sessions at home, couples  wore a SenseWear armband that tracked their energy  expenditure.

They also answered questions on how tired  they were afterwards, how much effort they put in and how much they enjoyed it.

Participants had previously undergone a half  hour treadmill test so the researches  could measure how many calories they  burned during exertion – and then compared the readings from the armband worn  during sex.

Men, for example, burned 9.2 calories per minute on the treadmill  – but only 4.2 in the bedroom.For women,  this fell to 7.1 calories while jogging.

And, to help settle another holy grail  question, the average recorded session lasted for 24.7 minutes – the shortest  being 10 and the longest 57 minutes.

While the figures aren’t quite the marathon  calorie burn some might hope for, they are better than those suggested in  previous research.

David Allison, a biostatistician at the  University of Alabama at Birmingham, found that the average person burns a mere  21 calories during the average session.

He discovered that sex lasted six minutes on  average –  ‘disappointing, isn’t it?’ – and that the energy output equated to a  paltry 20 or so calories – about the same as walking.

However, if done with enough gusto, sex can  still count as ‘significant exercise’, the Quebec researchers said, reporting in  the journal PLOS ONE.

Read more: DailyMail