When I want to ensure abdominal soreness, I go to this ladder set with clients:
1) perform 3 reps of a resisted ball rollout
2) perform 4 reps of a resisted ball curl up
3) 5 reps ball rollout
4) 6 reps ball curls up
And continue up the ladder until 12 reps of the curl up are performed.
If that doesn’t do the trick, try going back down the ladder by starting with 12 ROLL OUTS down to 3 CURL UPS.
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