That's really a challenge to get a full-body workout in that short amount of time. Try this: (1) Do as many pushups as you can to work chest triceps, and shoulders. (2) Do as many pull-ups as you can to work back, biceps, and forearms. (3) SPRINT as fast as you can up and down at least one flight of stairs. Do as many sprints as you can handle. This works your quads, hamstrings, calves, and melts the fat off of your mid-section. Sprints will also speed up your metabolism for several hours after your workout. If you have access to a gym then use the stairmaster for sprints. (4) After the sprints, lay down on a mat and do as many leg raises as you can to work your abdominals. Good luck.