We never did that in HS, but now I have a boy that does it after his 4x4 leg almost every meet. That, and he can't even stand for 5 minutes. I thought he just wasn't well-conditioned, but it's the end of our regular season now (Florida) and it's still the same. I asked him about it and he said (paraphrasing), "I go as hard as I can for 300 and then hold on for dear life." He's run around 50.5 consistently for a month on the relay and never broken 53 in an open race. You gotta love it.