I only played high school ball, but I remember, near the end of every practice, coaches calling for sprints drill until many vomited. Only then would they end the practice. Games were a relief, because you could rest when your squad was of the field. In practice, there was no rest period. A player that wasn't moving was not working out and labeled a quitter.

That said, it was a lot of fun.

http://www.cbssports.com/collegefootball/writer/dennis-dodd/24672161/coaches-no-longer-knock-heads-to-find-out-if-their-team-is-tough-enough