I don't know the medical reason why sprinting really hard makes one hurl, but, it does. In the old days when I raced, we used to compare different styles employed by various hurlers after a prime sprint, i.e. over the shoulder, under the arm, etc. An Australian I got to know pretty well, Jeff Leslie, was a good barfer. He employed going to the roadside, and just retch like mad. Body builders used to call it "The barf bucket method of training." Some folks are more prone to this than others, but I don't see it too much anymore. But, if Chris Hoy does, then maybe it will come back into style. I can only hope so. It provides a real indicator of just how intense the sport can be!! Later.