This is the template I recommend for ab training: super set 1 : 3-4 sets of lower ab exercise x 20 reps super set with upper ab exercise x 20 reps super set 2: 3-4 sets of lower ab exercise x 20 reps super set with upper ab exercise x 20 reps 3-4 sets of an oblique exercise like decline bench romanian twists - 20 reps per side 1 set to failure of a functional ab exercise like plank or ab roller