All you need for this move are two rags on a smooth floor. I used dumbbells for my wrists just to be a little more ergonomically correct. I have a few plates in my forearm and so try to avoid making it sore after a workout.
Little explanation needed, using your full body here, legs, booty, back , chest, arms, abs… everything. Keep this move controlled taking about 2 counts each way.
Start out with just planks if you want, as you get stronger add in half pushups, full push ups, then graduate to a static hold at the bottom point while doing your jack.