When Training your Abs to get stronger if you are not mentally squeezing them throughout each rep, you will not get the maximum benefit for your efforts.
There are 4 exercises to be completed for the recommended # of reps.
Upper Body Crunch 20 reps
Full Crunch 20 reps
Sprinters Sit Up 10 each
Leg Lifts 20 reps
Rest 2min
Repeat 4 times
This workout is an excellent challenge and I would like to encourage you to take your time during each rep and really squeeze your abdominal muscles.
