The death of Mr Stephen Begley during the Singapore International Triathlon last Sunday was tragic (Cardiorespiratory failure caused death of expat triathlete; Sept 13).

It was reported that the cause of death was cardiorespiratory failure, but I believe there was an underlying pathology that caused it, as cardiorespiratory failure is what ultimately happens when anyone dies. Most healthy athletes and national servicemen who succumb to sudden death during strenuous activity die of heart rhythm abnormalities.

Many life-threatening irregular cardiac rhythms do not show up during normal clinical examinations and basic ECGs.

Doctors who are asked to certify a patient's fitness to exercise are always put in a quandary. They can only guess the best they can with the available information.

Weekend warriors intuitively know when to stop when the pain of exercise puts a strain on their cardiorespiratory function.

Seasoned athletes, however, may push the boundaries of their endurance to improve themselves. That is where the trouble starts.

Short of very sophisticated and expensive investigations under the purview of a cardiologist, nobody can guess how the heart will respond under severe duress.

The best advice any doctor can give is: When in doubt, don't.

A stringent disciplined diet with an active lifestyle combined with moderate exercising guarantees longevity far better than a wanton diet desperately compensated for by overly strenuous, arrhythmia-inducing and heart-stopping exercises.

Yik Keng Yeong (Dr)