The Lust for Life hitmaker used to be known for his wild lifestyle both on and off the stage, but at 69, the singer has settled into a clean and healthy lifestyle - and just the idea of doing drugs is a big turn off.

Asked if there are any mind-altering substances he misses from his days of excess, he tells, "Oh, God, no. No no no no no. I've had a wonderful relationship with my body late in life. Even the thought of smoking weed gives me the creeps."

Iggy has plenty of reason to turn his back on illegal substances after a number of particularly wild drug binges during his heyday: "Going back, I had a binge on MDMA (commonly known as ecstasy) in the 1970s," he recalls. "And at a festival called Goose Lake in Michigan, I was snorting something they said was coke but I learned later was ketamine. I couldn't remember who I was for about 12 hours. I remember smoking crack before it was called crack. It was frightening."

The ageing star now prefers to spend his spare time practising Qigong, the Chinese art of gentle stretching and breathing exercises to help keep his mind and body at ease.

Describing his fitness regimen, he says, "The root of it is a series of exercises called Qigong, which form the basis of tai chi. I learned it from a Korean tai chi master named Don Ahn, who had a place in Soho (in New York). You don't need a funny suit. You don't need to go to a gym. You don't build no muscle (sic). It just gives you a good energy, good flexibility and good circulation."

Staying healthy is all the more important for Iggy as he prepares to mark his 70th birthday in April (17), but he won't be doing anything crazy to celebrate.

"I'm excited. I hope I make it," he laughs. "I'll probably have dinner with my wife (Nina Alu) somewhere with low lighting where we can sit close to each other. And if I'm lucky, I'll go to the beach that day. That's my idea of a wild time."

And as he mulls "extreme old age", Iggy admits he worries about becoming too dependent on others later in life.

"There is the possibility of being overreliant on others," he remarks. "Also, the worst would be the inability to enjoy life. I don't mind a little s**t in my day, but I need some sugar on that."

But Iggy has no plans to retire his famous shirtless look onstage anytime soon, declaring: "There's no age (too old to be topless), and the public can kiss my sweet a**, bare."