The One Direction singer used to train as a boxer before he found fame on The X Factor, the Daily Star reports.
He explained: "I did boxing from when I was 15 to 17. I love it and I've started training again now on the side, even though we don't get much time off for exercise.
"I'm trying to eat healthier so I can bulk up. I'd love to pursue it properly one day."
Malik, 20, applied for The X Factor in 2010 and has gone on to achieve worldwide success with bandmates Harry Styles, Liam Payne, Niall Horan and Louis Tomlinson. They are currently on the UK leg of their 2013 world tour.
As well as a passion for boxing, the star also said that he loves designing his own tattoos.
"All of my tattoos are based on my own art work," he explained. "I want to fill up my entire right arm to my elbow to start off.
"I've got loads of ideas. I'm more addicted to coming up with ideas for tattoos rather than the tattoo itself!"
Watch the video for One Direction's 'One Way or Another (Teenage Kicks)' below: