By Lin Xinyi

THIRTY-three years ago, Dimitrion Yordanidis completed a marathon at the age of 98.

While displacing the Greek as the oldest man to finish a 42km race might be a tall order, keeping fit during one's senior years is an achievable goal.

'The number one rule if you are starting to exercise - whether you are 20 or above 55 - is that it needs to be a gradual progression,' said Dr Cormac O'Muircheartaigh, medical director of the Singapore Sports Council.

But, first, get a comprehensive health check. Trying to do too much exercise too soon could be dangerous, and even fatal.

Last week, former Malaysia Cup football star Dollah Kassim suffered a heart attack during the Sultan of Selangor Cup veterans' game after playing for just 10 minutes. Being a former sportsman, said doctors, does not always count towards one's current fitness level.

One's recent exercise routine is more important than one's exercise history, noted Dr Jimmy Lim, a cardiologist at Novena Heart Centre.

He said: 'Studies have shown that if you have been exercising regularly, your chances of getting heart problems are reduced - even if you were obese as a child.

'Those who were competitive but became inactive are at greater risk.'

Still, former athletes do have one advantage.

'You might be able to regain your fitness in a shorter time,' said Associate Professor Tan Huay Cheem, director of the National University Heart Centre, Singapore.

'But you might also put yourself at risk because you think you can do the same things in your old age.'

Ideally, one should exercise for a minimum of 30 minutes at least three times a week.

The half-hour period can be broken down into shorter sessions, such as three 10-minute workouts.

Alternatively, burning at least 1,000 calories through some form of physical activity - household chores included - should suffice.

That is the equivalent of walking about 16km a week, or over 2km a day.

Those looking for a more rigorous workout can do so by increasing the frequency, intensity or duration of the exercise - be it walking, running, cycling or swimming.

While the ability to tolerate a more intensive workout differs for each individual, it would be safe to make the step up after completing a particular routine consistently for two to four weeks.

And, only if they do not experience symptoms such as breathlessness or chest pains.

Said Dr O'Muircheartaigh: 'The key is setting realistic goals. Other than cardiac and respiratory risks, you also have to look out for musculoskeletal injuries - like ankle, knee, hip or back problems.'

linxinyi@sph.com.sg

This article was first published in The Straits Times.

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