By Jeanette Wang

IT MAY be the triathlon's shortest leg in terms of distance and duration, but do not underestimate the swim portion of the three-discipline event.

This applies to even strong pool swimmers, experts told The Straits Times yesterday.

Typically held in open water, the swim segment can range from 200m in a mini-triathlon to 1.5km in the Olympic distance and up to 3.8km in the Ironman.

Swim leg is most stressful

All the triathlon deaths recorded by USA Triathlon in the two years before August last year happened during the swim portion of the event. Researchers have an intriguing theory.

Long QT syndrome

When this genetic condition strikes, a heart's electrical system can go haywire, degenerating into a possibly fatal arrhythmia.

One form of long QT seems especially bothered by swimming. A Japanese study several years ago found that irregular heartbeats occur more commonly during swimming than during the same level of aerobic activity, like running, on land.

Suggestions for safer swims

- Have compulsory swim trials for first-time participants. The Singapore Biathlon (1.5km swim, 10km run race), organised by Safra and the Republic of Singapore Navy, requires first-timers to be able to swim 1.5km in the pool (30 laps) within 40 minutes.

- Have all participants attend compulsory open water swim classes before races, which race organisers should conduct as a complimentary service. Don't mind paying for classes? Try Yellowwfish, Synergy Multisport or Tribob. Or organise your own sea swims with friends. Safety first - swim near the shore, always have people watching and swim with a float if not confident.

- Set up smaller swim loops and/or make the course run parallel and closer to shore, says swim coach and avid triathlete David Lim, 41. For example, have three loops of 500m instead of two loops of 750m for a 1.5km swim. This way, participants come up to shore more often, allowing them more chances to rest.

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