Dr. Charles Eugster, a 93-year-old British bodybuilder, did not begin weightlifting six years ago as a way to stay in shape or to occupy his time. No, Eugster had a more, shall we say, ambitious rationale.

"The idea is to turn the heads of the sexy young 70-year-old girls on the beach," Eugster told BBC News.

After an athletic youth in which he was a competitive rower, Eugster lost his sturdy physique during 30 years as a dentist. In his late 80s, he noticed the complexion of his body had changed, and he wasn't happy about it.

"I'm extremely vain," Eugster said. "I noticed I was getting fat."

So for the past six years, Eugster's been hitting the gym three or four times a week, even working with a former Mr. Universe as a trainer.

At a recent competition he did 57 dips, 61-chin-ups and even pulled off 48 abdominal crunches in 45 seconds.

If Eugster's routine sounds extremely impressive, that's because he's a human anomaly. Most seniors in their 90s are advised to avoid lifting weights and doing other strenuous forms of activity.

"[Eugster] is unusual and there is a small minority of the population that can undertake that sort of vigorous activity into their 90s, but that's not true of most of us," said Steve Iliffe, a professor of primary care for older people at University College London. "Within reason it is never too late to start exercising, but you do have to remember there is a difference between exercise and physical activity."

Eugster said that bodybuilding at an older age is like exchanging an old car for a new one. The better shape the car is in, the easier it will be to trade it in.

"If you have taken care of your old car, it won't cost you so much," Eugster said. "But if you have neglected your car, it's going to cost you a lot."