Hold a medicine ball or dumbbell goblet-style in front of your chest (A). Sit back into your squat (weight in your heels, sending your butt back) (B). As you stand, press your arms straight up while twisting your torso so you’re turned to one side (C). Squat again, straightening out your upper body on the way down; on the way up, press and twist to the opposite side. That’s one rep. Do 8-10 reps.