Plank Pyramid
Try this set of exercises to work on your core:
10 seconds plank jacks, 10 seconds rest 20 seconds plank punches, 20 seconds rest 30 seconds plank hip rotations, 30 seconds rest 40 seconds plank pikes, 40 seconds rest 50 seconds plank leg lifts, 50 seconds rest 60 seconds plank hold, 60 seconds rest. REPEAT in reverse, starting with 50 seconds plank leg lifts.
