What is the “stir the pot” plank exercise? Perform a forearm plank with your elbows supported on a stability ball, also known as a Swiss ball, and the balls of your feet resting on the ground.

you could put your toes on a tree and do a decline plank, or you could put your hands on a park bench and do an incline plank. No doubt, the standard, straight-arm high plank is a great exercise.