because they don’t have to swim and bike before they get to the run. The better question is why do some triathletes wear spandex during training runs when they could have worn running shorts?
Unexpected responses. I find tri shorts/spandex infinitely more comfortable than running shorts. No chafing for me in tri short, but, I have had some chafing with running shorts. Plus, I like more support for the boys than I get with the liner in running shorts.