Manchester United star Wayne Rooney credits his superhuman fitness to regular boxing sessions.

The 24-year-old, who takes on Bayern Munich in the Champions League tonight, claims he has a new outlet for taking out his frustrations.

He said: "I used to do boxing and football. I was training every night with one of them and when I got to about 15, Everton said I had to stop boxing if I wanted to carry on playing football.

"I had a good chance of making the first team, so I stopped. I still love watching boxing.

"It is a big thing in my family. I can still do a bit now after training, but obviously not fighting.

"I enjoy it. It is a good way to get rid of some anger."