3. Curl and lift Holding a 3- to 8-pound dumbbell in each hand, sit on the ball with your back straight and knees bent so they’re in line with your ankles, feet flat on the floor. Let your arms hang by your sides, palms facing forward. Squeeze shoulder blades down and together to keep torso lifted. Bend your elbows, keeping them close to your sides, and lift the dumbbells up toward your shoulders (A). Lift elbows up and out to shoulder height, turning palms down as you lift (B). Bring elbows back to your sides and complete reps. Strengthens biceps and middle shoulders.