Like their counterparts throughout the world of triathlon, scientists at the University of Portsmouth in the United Kingdom looked into why more athletes die during the swim leg of triathlons compared to during the cycling or running legs. Professor Mike Tipton and his colleagues at the Extreme Environments Laboratory in the University of Portsmouth’s Department of Sport and Exercise Science also delved into the issue why these triathletes die during the competition, but not during training.

According to the information provided by the University of Portsmouth, 30 out of the 38 athlete who died in American triathlons between 2003 and 2011 did so during the swim leg. Professor Tipton suggests they may have died due to Automatic Conflict. Autonomic Conflict presents a significant risk when the body’s cold shock response and diving response are activated simultaneously. The two different responses work in opposite directions. While cold shock response increases the heart rate and leads to hyperventilation. It is generally caused by anxiety brought upon by competing in a mass participation race and an untrained, unprepared-for entry into cold water. The diving response slows the heart rate down in order to conserve oxygen. It is caused by getting the face wet, sustained holding of the breath, and water going into the nasal passage. As a result, the body receives two different physiological directives in conflict with one another, both intensified by the anxiety generated by the crowds of flaying swimmers around them in deep water. When the athletes do not breathe as they normally do, more water can enter their nasal package. The combination of these factors can in turn cause the heart to start abnormal rhythms and, ultimately, cardiac arrest.

Unlike mass starts at 10K runs or cycling century rides, the start of triathlons and open water swims can be chaotic and confusing for both the uninitiated and veterans. Splashes on all sides, swimming in an unknown direction buried in a large group of athletes hitting, grabbing and swimming crookedly is enough to startle any athlete. When cold water is added for the uninitiated, it can be especially terrifying.

This is why teams like Tower 26 and the Open Water Swim Club practice mass starts so athletes can become accustomed to the typical beach start chaos. But the ultimate advice for the newbie and veteran who prefers to experience a more enjoyable swim is to simply wait and stand aside for the Type A aggressive triathletes to beat on each other. “Just stand to the side and give the others a head start,” advises Steven Munatones to those who are more interested in completing a race instead of being competitive. “Start on the very fringes of the pack and avoid having to run in with everyone else. Even if you give others a 10-15 second head start, walk in at your own pace. Give yourself plenty of room without having to deal with swimmers banging into you. Your swim will be largely free of physical conflict if you are a bit patient. Everyone wants to avoid being zip-lined or elbowed, but in the middle of a large pack at the start of a swim or triathlon, contact is inevitable.”

Race directors can also help the situation. The World Open Water Swimming Association recommends that its sanctioned races avoid the first turn being a 90° turn close to the start. “When there is a 90° turn required early in an open water course, there is a significantly higher probability of contact,” says Munatones. “WOWSA recommends that courses are designed so the athletes can take the first turn at an angle. Something like 120° allows all the athletes to cruise around the buoys without a sudden change of direction like a 90° or 180° angled turn does. When athletes are required to make a sudden change of direction in the open water, they often use their legs in a scissors kick or breaststroke kick, and they take wider arm strokes than usual. These actions lead to knees, feet and elbows thrown in different directions, occasionally in the head or body of another athlete.”

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