Strengthen your core AND your lats at the same time! Starting in a plank from hands, tuck the tailbone under (tail between your legs) and press the ribs down (hollow body). Press the ground away, pulling the shoulder blades apart (protraction) while pulling them down your back (depression). Rolling onto the toes, lean the shoulders forward of your wrists without bending at the elbows or collapsing the shoulder blades together.