The goal of this workout is simple: pain . . . lots of pain. Pick several exercises (most of which should cause you tons of dread) then assign rep totals to each exercise until you total the 300 total reps. The try to complete three rounds of 300 in 45 minutes. You should FAIL to reach 900 the first few times you attempt this workout, or you have not selected a hard enough group of exercises.
My 300 rep breakdown:
5 laps on track
20 push up
10 Chin ups (assisted)
10 Russian twists with 6 lbs weighted ball
40 side lateral crunches (20 each side)
10 Bird dogs
10 fire hydrants
50 arm extensions
50 lunges w/ 10lbs weight (each leg)
50 standard crunches
10 step ups each leg
10 prisoner squat w/steps
I did two round of this in just over 45 minutes. Then I went home and thought about crying.
Oh By the way, this is the song that has been stuck in my head for three days. Enjoy.