Begin in a full pushup position wit hands on floor slightly wider than shoulders and legs extended with shins on top of a large, soft medicine ball.
Roll ball toward upper body while lifting hips toward ceiling, keeping arms and legs extended, until toes are on ball.
Bend elbows about 90 degrees out to sides, lowering top of head to just touch the floor. Straighten arms to return to pike, the lower hips toward floor while bringing ball back to starting position. Repeat.