Stand with your left foot on one end of a handled resistance tube, feet wide. Hold the other handle with both hands at chest height in front of you and rotate shoulders to the left [1A].
Pull the band across your body to the right, ending with hands at shoulder height in front of you and torso facing to the right [1B]. Return to starting position and repeat.
Do 10 reps, then repeat with right foot on the tube. (If you don’t have a resistance band, hold a 3- to 5-pound dumbbell instead.)
Strengthens: Core (which includes your lower back)