HOW: Begin in a plank position with your arms straight and underneath your shoulders and your legs straight out from your hips with your toes pushing into the ground. Shift your bodyweight to one side/arm, and bring the other arm forward in a diagonal motion with your thumb up and your shoulder blades engaged. Return to the starting position and repeat for the prescribed amount of reps.
FEEL: You should feel your shoulder and core muscles working.
COMPENSATION: Keep your shoulders, hips, and ankles in line, don’t arch your back or hips.