HOW: Begin in a plank position with your forearms on the ground, elbows straight down from your shoulders, and your feet straight out from your hips with your toes pushing into the ground. All at the same time, rotate your chest and hips to face one side putting all of your weight on one arm. As you do that, let your feet hold your body up with your toes facing the side your body is now facing. Then, rotate back down to the starting position.
FEEL: You should feel your core and shoulder muscles working.
COMPENSATION: Make sure to rotate your hips and upper half all at once.