This three-move cable ab workout is simple, but brutal. Each of the exercises are performed for 3 sets of 10-12 reps. So, what's the catch? You'll perform a dropset at the end of each movement. Take each set to failure and expect to have nothing left in the tank!

Machine Ab Workout
1
Kneeling cable crunch
After the final set, perform a single dropset.
3 sets, 10-12 reps
2
STANDING CABLE HIGH-TO-LOW TWIST
Perform for all reps on one side before switching to the other side. Rest as little as possible between sides. 
Cable Cross-Body Pull
After the final set, perform a single dropset.
3 sets, 10-12 reps (left side, no rest)
Cable Cross-Body Pull
After the final set, perform a single dropset.
3 sets, 10-12 reps (right side, rest 1 min. )
3
Cable reverse crunch
After the final set, perform a single dropset.
3 sets, 10-12 reps (rest 1 min. )
Ab Workout Abs