Begin in forearm plank. I like to position my arms so fists are close to elbows for this one.
Slowly take the weight of one forearm, without tilting, rotate to one side so shoulders and elbows are stacked on top of each other. Control and quality is vital so only rotate as far as you can maintain a solid plank.
Slowly return to starting position
And repeat to other side.
Hips and shoulders rotate as a single unit. Do not allow the plank to fail while rotating.
Aim for 45 sec of slow rotations, 20 sec rest, x 3 times.
Take more rest time if needed to maintain a quality 45 sec.