Sexercise? Forget it! The average person burns only 21 calories while having sex
It's one of those urban myths that we love to believe is true - that it's possible to burn up to 300 calories during sex.
But using a session between the sheets as an excuse to skip the gym is not as foolproof as you might think.
For the average person burns a mere 21 calories during the average session, researchers claim.
David Allison, a biostatistician at the University of Alabama at Birmingham, decided to investigate the claim as part of a study into widely-health beliefs.
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.
His report in today's New England Journal of Medicine says false assumptions such as this are the part of the reason for the obesity crisis.
Among the other widely-held beliefs he investigated were whether snacking or skipping breakfast is bad or whether physical education classes make a big difference to children's weight





