both involve the same exercises.
1. complete without stopping
100 crunches (hands behind head)
50 left oblique crunches
50 right oblique crunches
50 reverse crunches
V* til failure
2. repeat cycle for 10-20 minutes without stopping
10 left oblique
10 right oblique
20 reverse crunches
after time is completed wait 1 minute and V* until failure.
* = lay flat on back, raise feet 6 inches off the ground and raise shoulders off the ground. Keep arms at your side. Hold position.