Sir Paul McCartney does handstands to keep fit.

The 'Hey Jude' singer has revealed his fitness secret is standing on his head, admitting it's something he has done regularly for the past 50 years along with working out at the gym.

Speaking about his fitness regime, he said: "I feel pretty fit.

"I do a bit of the cross-trainer, a bit of running, a bit of cardio and then I do some weights, some abs on the Swiss ball, before ending up on the mat doing a few stretches. And then standing on my head."

The 72-year-old former Beatles star continued to explain his unexpected talent often surprises muscled youngsters in the gym who are unable to match the impressive feat despite their good fitness levels.

He told the Daily Mirror newspaper: "That's my big claim to fame! I actually learned it in the 60s, it was a yoga thing, and my argument is I need flexibility not strength.

"But what's cool about it is that I'll be in the gym with all these guys doing really big weights, whilst I'm there doing not big weights, and afterwards, when I've done my headstand for about five minutes, these big guys will come up to me and say, 'That was pretty impressive, man!'"