And in Justin's case he's so keen to show us the results of his hard work that he's taken to Twitter to post topless snaps of himself.
Justin Bieber shows us his six-pack
OK, so JB might have a little way to go before he can give JLS a run for their money in the beefcake stakes but everyone's got to start somewhere and well, who wouldn't want a stomach like that?
Meanwhile, Liam Payne has also hit the gym in a bid to avoid looking like Mr Puniverse on the beach.
“He said he’ll be taking his new girlfriend away when he gets the chance and wants to be fit. He’s a naturally slim lad but if he keeps following the tips he’s been given, he’ll have that six pack in no time.”
Let's hope he takes Justin's lead and starts tweeting snaps of his progress, eh?
> JUSTIN AND LIAM SHOULD FIND SOME INSPIRATION IN OUR GALLERY CELEB BEACH BOYS...