Instead of the usual high repetition based ab workouts like sit up and crunches, this workout is going to incorporate weighted exercises which helps to really build the thickness of your rectus abdominis. This is a circuit based workout so make sure you take little to no rest in-between exercises and take no longer than 45second-1min breaks.

3 sets 

Hanging leg raise – 10-15 repetitions

Rope crunches – 10-15 repetitions

Med ball twists – of 15 reps (either side)

Cable wood chopper – 10-15 reps (each side)