PUSH-UPS AND ABDOMINALS - TIMED CIRCUIT TRAINING
Push-ups circuit training combined with abdominal exercises can be found in U.S. Army physical training manuals in many variations. As a timed event, this is excellent for groups or individuals. The trainer would 
keep time and call the exercises until you have completed all eight sets. If you are getting too fatigued to complete the particular exercise with the proper form, use a partial motion for the exercise so that you are still working those muscles until the trainer calls out to switch to the next one. Timed sets are designed to increase strength and muscle endurance. You will probably feel some muscle soreness for a couple of days.
This is an excerpt from Colonel Bob's new book, 600 Push-ups 30 Variations.
