One Direction heartthrob Harry Styles recently confessed that he's currently only getting around four hours of sleep per night and has been hitting the gym, but his lifestyle has sparked concern because it doesn't involve enough rest.

Dr Arun Ghosh told British gossip magazine Heat that Styles needs to make sure he's getting enough sleep because his busy schedule means that he could find himself getting run down very quickly:

"It sounds like he is going overboard and not resting his body is cause for concern. Harry's obviously young and is clearly able to do it now, but there's only so long you can go on before you get exhausted."

"If he gets too tired, he won't physically be able to manage and he may collapse. Sleep is so important and the most worrying thing is that Harry admits to only getting four hours' sleep a night. That's certainly not enough, especially after intense, gruelling activity."

Earlier this month, the 'Story Of My Life' superstar confessed that he has a strong bond with the rest of his band mates and that they regularly talk about their individual girl problems together:

"Yes! You know we travel all the time together, so if someone’s having problems with a girl, they’ll come into the car and tell everyone what’s going on."