This hypothesis makes some sense to me.

For the amateur sports enthusiasts among us, here's an interesting article at WaPo about the possibility that panic attacks may cause numerous unexplained deaths in the swim portion of triathons.

The rate of deaths isn't large -- nine people in one summer, out of 243,000 competitors in a year.  But from the sound of the article, non-fatal panic attacks aren't rare in the swim portion of triathlons.  

In the swim event, a combination of stresses can lead to a panic attack (or something like it): the excitement of the moment, the chaos of swimming into and over other people, the chest constriction of the wet suit, the darkness and coldness of the water, competitiveness and the desire not to quit when friends and family are watching. On rare occasions this leads to drowning.

Discussion threads on blogs suggest that panic attacks are common even among experienced athletes, although apparently nobody in the triathlon industry has attempted to learn how common they are. Some coaches mention them, but many triathletes train without coaches. Race directors in general don’t name panic attacks as potentially lethal but manageable hazards, though they do warn about wet roads for cyclists and high temperatures for runners.

There are also some quotes from triathletes that support the hypothesis.

Every once in a while, someone who knows I like biking and swimming and tolerate running well will suggest that I try triathlons.  I have absolutely no interest in triathlons because while I love swimming in pools, I don't enjoy swimming in open water, and the idea of swimming in a crowd in open water is absolutely repulsive.  (I feel a little claustrophobic just sharing a lane with more than one other person.) So the idea that some people might suffer panic attacks doesn't surprise me.

(h/t the Agitator)

Comments

[Margie]

That certainly tracks with my triathlon experience this summer - I got about 100 meters into the swim, and the feeling of people near my legs freaked me out enough to mess up my breathing. It was an odd sensation, because I wasn't scared, particularly, but I was panting and couldn't control my breathing.

I was able to tread water and slow down my breathing, but when I put my face back in the water for the craawl, I started panting again, so I ended up doing the sidestroke for the next 100 meters or so. After that, I was fine again.

I still enjoyed the overall experience enough to want to do another tri, but I'll make sure to start in the back of the pack next time - I didn't have a problem with the lake swim, but having people brushing up against my legs wasn't so good.

[Kim (in IA)]

I have resigned myself to doing mostly breast stroke in triathlons. I used to strive for better times but now I take it easy. It is a better view that way. I actually like swimming distances in the open water. Even with that mindset, I still feel anxious while I'm waiting and for the first section of the swim and whenever the competitive pull to go faster hits me.