There are a lot of far more effective ways to work the “core” than by doing a bunch of crunches, and you can hit other key areas at the same time. As always, focus and execute with perfect form.
warm up run
shoulder openers, squats, etc.
3×10 pull ups
barbell pullover 35#/push up: 10-8-6-4-2 ladder
P1: 4x seated kb/chain pull @72#
P2: plank hold
KTE on rings
Athletes: Margaret, Allison