April 6, 2010 -- Triathletes may aptly be called iron men and women, but a new study shows they aren't invincible.
Researchers say at least 14 people have died in triathlons between 2006 and 2008. That equates to a sudden death rate of 1.5 deaths per 100,000 participants, double the rate associated with marathons (0.8 per 100,000).
Of the 14 deaths, 13 occurred during the swimming portion of the race and one during the biking portion. Drowning was the declared cause of death in each of the swimming deaths, but seven of nine athletes who had autopsies had cardiovascular abnormalities that may have contributed to their deaths.
Researchers say the high rate of sudden deaths during the swimming portion of triathlons, which include swimming, biking, and running segments, suggests that logistical factors and environmental conditions may contribute to risk because it is difficult to spot and reach distressed athletes in open water.
"Because triathlons begin with chaotic, highly dense mass starts involving up to 2,000 largely novice competitors entering the water simultaneously, there is opportunity for bodily contact and exposure to cold turbulent water," write researchers Kevin M. Harris, MD, of the Minneapolis Heart Institute Foundation, and colleagues in the Journal of the American Medical Association.
The study also showed that deaths were more common in triathlons involving greater numbers of participants.
Although researchers say mass screening before competitions may be impractical, individual athletes may want to consider undergoing a cardiovascular evaluation before entering a triathlon. Establishing minimum participation qualifications, such as swimming proficiency, could also improve triathlon safety.
The study analyzed online race results of 2,971 USA Triathlon-sanctioned events involving a total of 959,214 participants between January 2006 and September 2008.