HOW: Begin in a plank position with your hands straight down from your shoulders and your elbow straight. Your legs straight out from your hips with your toes pushing into the ground. Keep your back and hips flat. From here, bring one knee up and out to the side of your elbow and as you return it to the start position do the same for the other side alternating each leg.
FEEL: You should feel your core and hip muscles working.
COMPENSATION: Don’t let your hips drop or come up, keep them flat in line with your body.