Run.

-Run 400 meters leisurely to get loose.  If you are near bleachers or hills, run up and down 5-10 times.

-After a enough rest complete the following:

sprint 40 yards then 10 push ups
quick rest (long enough to be able to sprint hard for following sprints; less than 1 minute)
sprint 60 yards then 10 push ups
quick rest
sprint 60 yards then 10 push ups
quick rest
sprint 100 yards then 10 push ups
quick rest
sprint backwards 50 yards then immediately turn and sprint forward 50 yards then 10 push ups

quick rest then

-Run 400 meters as fast as possible