I picked up a great series of exercises from Strength and Conditioning Journal.
Put your feet up on the swiss ball, while you lay flat on your back on the ground. Lift your hips off the ground and hold for 10 seconds. Do this in sets of 6-10 x 10 seconds. Next, do hamstring curls while in that same position. Pull the heels to your butt and then extend back to straight.
I feel that various pillar movements with the ball adds great variety and stress while not overloading the CNS like a sledgehammer or axe chop can…a lot of the “real world” or “strong man” stuff is total body and is exhausting…too exhausting.