I don't know if you've ever heard of these but their called gassers (atleast that's what my h.s. football team called them). Do this.....run across the football feild four times (it will be 200 yards), wait 20-30 seconds, than run it again....keep doing that for about 10 min. That ought to get you worn out. The next day, run 40 yrd. sprints with the tire, and only stop for 30 seconds. Just keep rotating between the two. That ought to get you ready for the season. Good Luck!!!