Hey, my public high school tennis coach used to tell me in a tough match, where it might come down to me winning for the team to win, "If you don't win we'll be dedicating 25 four-court suicide sprints to you next practice."
Needless to say, I got out there and kicked my ass into gear during those matches.
I had a lot of hardass teachers in high school, but they may be the exception. I can only speak for one school district.