What we don’t not know.
It’s a dreaded headline for anyone involved in the sport—”Triathlete’s Death Mars Event,” and it seems all too frequent.
Why are triathletes dying during races? Is the cause avoidable? Furthermore, how do triathlon’s death statistics compare to those of other endurance competitions? And, most importantly, is there something inherent in the sport of triathlon that is responsible for these deaths? After 12 fatalities at sanctioned races in 2011, and several high-profile fatalities in 2012, USA Triathlon initiated an investigation into the 45 competition-related deaths over the 9 years from 2003 to 2011 to answer these questions.
The fact is that strenuous endurance events result in unexpected deaths, sometimes because of electrolyte and water balance issues or because of undiagnosed cardiac problems. But because most deaths have occurred during the swim leg, a popular suspect in the deaths in triathlon as opposed to the marathon has been swimming-induced pulmonary edema (SIPE). SIPE was loosely cited in the media as a possible cause of death for the athlete who perished in Ironman New York this year, an incident not included in USAT’s study.
SIPE is basically a pressure-induced suffocation in which blood seeps from lung capillaries into lung airspace. It’s a condition typically experienced by fit, well-conditioned athletes. It’s thus a possible answer to why some of the deceased have been experienced triathletes, even though we might expect neophytes to be more adversely affected by the swim leg.
The USA Triathlon investigation, however, reported “no clear evidence” that SIPE is the reason behind athlete fatalities. Nor did it “exclude the possibility of a role for SIPE in the victims’ deaths.”
Why the lack of clarity?
There seem to be two problems at work here. First is the inherent problem of diagnosing an individual’s predisposition towards SIPE. What makes one athlete experience it, but not another, is not well understood by the medical community, and is harder to diagnose than cardiovascular pathologies.
So, fine, USAT is not in the medical research business. That makes sense. Our governing body is not here to “cure cancer” so to speak, its role is to ensure the safety of participants and longevity of all things triathlon.
This brings us to the second problem: the investigation was only able to use cursory information about each death it included. Information about victims’ medical histories, autopsy reports, wetsuit details, water conditions during the swim leg, and water temperature was either incomplete or unavailable. Unfortunately for people wanting more answers, these are critical pieces of evidence in assessing SIPE and its known triggers. Without such evidence the report really should only suggest something to the effect of we do not currently have evidence to address SIPE as a cause.
Hopefully no athletes interpreted USAT’s report as reason not to worry about a mysterious condition. If any did, their fears were mistakenly allayed—the reason why triathletes have died is not not-SIPE.
After equivocating about SIPE, the USAT investigation report advised racers to stop and seek help if they experience shortness of breath during the swim leg. That is certainly a good start. But athletes should also know that SIPE, because it impairs oxygen intake, will cloud judgment and thought processes (which are already arguably clouded when in one-track-mind race-mode). So, understanding its symptoms prior to competition is really important. Somewhat thankfully, SIPE has been in triathlon conversations long enough that there are a few online resources (here and here are examples).
My intent here is not to split linguistic or methodological hairs. This isn’t a diatribe against USAT, which in fact made an important first step with this investigation.
Instead it’s an exhortation for more work, understanding, and investigation: care should be taken across the board to provide safe race environments as well as accurate information. If the information doesn’t exist, we have compelling reasons to pursue it, through industry and medical research.
Online commentary about report (sparse):
JAMA report on sudden death in triathlon from 2010: