Michelle Obama puts us all to shame

Push-ups aren't really something that women tend to do. There's a belief that we can't do them properly, and when an exercise is this difficult, who wants to challenge that theory? Better to start from the knees.

This video of Michelle Obama, though, seems to challenge that idea. "Challenged" by Ellen DeGeneres (OK, the whole thing is stage-managed - why else are they wearing trainers? - but it's still cool), the FIrst Lady pumps her own body weight 25 times without seeming to break a sweat.

"In my opinion this is one of the best functional exercises there is," says fitness trainer and Sun columnist Zac Taylor. "You're working your chest, back, shoulder and triceps and engaging your core at the same time. You can do this anywhere and it's free."There is a myth that women aren't meant to do push-ups, but there's no need to start on your knees - as these two fortysomething Americans show. "I think sometimes women are scared of doing push-ups, thinking they're going to build too much muscle but this is not the case," says Zac.But the exercise is hard until you have at least some upper body strength. "If you find it too difficult, start with your knees on the floor then build up to a full body push-up," Zac advises. "You can add them into any workout, or even do them at home."

If you lack motivation, just think of how beautifully toned the First Lady's arms are, at an age (48) when most women are reaching for shrugs, shawls and cardigans.