Iron age: Bodybuilder and champion rower Charles Eugster, 94, isn't the only pensioner to reap the benefits of regular exercise

Luke Blackall explores a growing trend

Dr Charles Eugster will begin defending his title at the European Strenflex championships tomorrow. The competition will see him undertake a gym-based decathlon, where he will strain every sinew to try to do more chin-ups, press-ups and a heavier bench press than his competitors.

If he had any competitors, that is. "The problem is, I'm in the 90-year-old category, and there isn't anybody else," the 94-year-old tells The Independent over the phone from Germany, in between training sessions. "The next youngest person is 85."

The Strenflex competition gives competitors points for how they achieve in each event, or percentage of bodyweight lifted, which is calibrated according to the age group the competitor is in. Eugster is hoping to be in the top 10 in the points table. "A couple of years back, I managed to get the highest number of points of any age group," he says. "But I think that was a fluke because it only happened once."

Strength is not his only talent. He also competed at the World Masters Rowing regatta in Italy this year, where he entered five races and won five gold medals. He is in training for his next target – to run in a 100m race. "I'm probably pretty lousy," he says. "But next year I'll be 95 so I'll be in a higher category!"

Eugster's story remains an exception, but comes at a time when more elderly people are being encouraged to take exercise against a backdrop of an ageing population (by 2021, it's estimated that 19 per cent will be pensioners) and the associated costs.

A study published this week by the British Journal of Sports Medicine, which looked at nearly 3,500 people over eight years, showed that those who took up four years of regular activity in later life (the average age was 64), were seven times more likely to age healthily.

"It suggests that we don't have to have a lifetime of fitness to get benefits in older age – it's something that you can pick up later on and still get the benefits," says one of the scientists on the study, Dr Mark Hamer, of the Department of Epidemiology and Public Health at University College London. But he adds a note of caution: "What we do know about exercise is that the minute you stop exercising, it doesn't matter how much you've done, you do lose the benefit very quickly. So it's really a case of you've just got to keep at it!"

The next step, Dr Hamer believes, is looking at the way the public is educated about the benefits and the barriers to old people exercising. One person hoping to encourage more seniors to be physically active is Michael Cain, of Exeter, whose grand-daughters refer to him as "Sportacus Grandpa". Although, at 64, he is 30 years younger than Eugster, he, too, is not letting traditional notions of age stop his ambitions. After starting to go to the gym in his fifties, Cain has just qualified as a gym instructor, specifically to teach the Les Mills Bodypump class.

"I'm just generally alarmed at a lot of people of my generation because, one by one, they are falling prey to illnesses, or aches or pains, or physical injuries. And I strongly believe this is because they are taking very sedentary lifestyles now. And it's a downward spiral," he says, but adds that his story has inspired others. "One or two [friends] have actually said, 'We've never been to the gym before, but we're actually going to come to one of your classes'. So even among my small group, I've been quite inspirational."

Today, there are a number of sports clubs for "masters" or "veterans" out there, and gyms such as Grace Belgravia in London report that nearly a fifth of their personal training sessions are taken by the over-fifties. But those such as Dr Eugster remain pessimistic for a costly future with a growing ageing population in which obesity and diabetes are on the rise, unless the importance of fitness is realised.

"Quite simply, I just want to change the world, that's all," he says, with a laugh.