In-Season Conditioning (high school)

I have always preached to out kids that if we need to run conditioning drills at the end of practice then are not working hard enough in practice. That being said we preach running all the time. Don;t job, run to the back of the line. Don;t walk back to the huddle RUN! We do some sprints during the week. I would say the kid's favorite is tag. WE line them up on the goal line and put a coach @ the 40. Blow the whistle and yell out 2-3 names. Those guys are it. Anyone they tag has 10 pushups (or whatever). If they don't tag anyone they have 10 pushups. It gets really fun and competitive. My greatest concern is for the kids to have thier legs back Friday. With so many of our kids going both ways and some kids NEVER coming off the field they need to have plenty of rest before the game. Most of the conditioning would be on Tues, cutting down on Wed, with none on Thursday. Honestly I do not think I have ever lost a game b/c my players were out of cardiovascular shape. WE have lost plenty because they were not strong enough or fast enough, but in terms of cardio shape I think what we are doing works. WE do run hard over doubles though, and throughout the summer.