Singaporeans may be becoming more sedentary, but there are also many who take part in events like marathons.

It was the tragic death of Mr John Gibson at last month's Standard Chartered Marathon Singapore that brought the issue of health screening to the fore.

Dr Derek Koh, head of Thomson Lifestyle Centre, said screening is beneficial before fitness events, especially for those that go beyond one's usual training routine in terms of intensity or duration.

He said: "There are often incidences of seemingly 'unexpected' fatalities, as many forms of heart disease can remain silent until the heart is pushed to its limit. These conditions may be picked up with health screening."

Some countries, like the United States, require pre-participation screening in sports events.

But what exactly does health screening entail?

Dr Koh said the process typically begins with a consultation and physical examination to assess one's health status, and to understand the purpose of the screening.

This is usually followed by blood, urine and stool analyses, with radiological scans and a treadmill electrocardiogram (ECG).

In a treadmill ECG, the person's heart health is monitored through walking on a treadmill that gradually increases in speed and incline.

He recommended that screening be done a week or two before the event to ensure one is able to take part in it.

Costs vary, he said, but "as a rough guide, basic screening packages may start from $300".

Dr Koh pointed out that some people may have misconceptions about health screening.

"A common complaint comes in the form of stories about friends or acquaintances who had done screenings and yet succumbed to diseases soon after," he said.

"Firstly, we must remember that screening results represent one's current condition. Some results may have little predictive value and should be checked regularly.

"Secondly, the choice of screening must be tailored to the individual and his risk levels. And this must be matched by his willingness to do the recommended tests."

However, health screening is not just for those who wish to take part in sports events.

Dr Koh said that chronic diseases like diabetes and hypertension can be silent, while cancer, if detected early, can be treated much more easily.

To check for these diseases, he recommended a yearly screening after the age of 40.

Jose Hong