We should try and go beyond what is effective to what is optimal. Why spend a lifetime doing 10+ exercises when we can get the same benefit from doing 2 – 3 harder movements that actually test us? If you’re doing hanging or lying leg raises, planks and side planks along with L sits you simply won’t need the other stuff. And definitely ditch the crunches. Unless you basically have no ab conditioning at all they are pretty useless.