Start standing with your feet hip-width apart and a dumbbell in each hand.
With control, step your right leg behind you and toward the left as you lower down into a curtsy lunge. Be sure to keep your core engaged, your chest up, and your spine long (there shouldn't be any arching or rounding of the spine).
With control, push your left foot into the ground and squeeze your left glute as you lift up and out of the lunge, returning to the starting position.
Once you're back at the starting position, raise both arms out laterally to shoulder height. It should look like you're making a "T" with your arms. Be sure to stay controlled as you lift your arms up, and avoid shrugging at your shoulders. If you feel yourself raising your shoulders toward your ears, use lighter weights. Lower your arms down to your sides with control.
This counts as one rep. Continue alternating between the left and right sides in the curtsy lunge.
Perform this exercise for 40 seconds, then take 20 seconds of rest.