V-Sit With Single-Arm Chest Fly Begin sitting with your heels planted about two feet from your butt, holding the weights at chest level with a slight bend in your elbows. Lean back a few inches, pulling your abs toward your spine to keep your spine long and straight. The left arm remains still, as you open your right arm to the side, making sure the weight doesn't go beyond your shoulder. Bring your right arm back to center and repeat on the left side to complete one rep. Image Source: POPSUGAR Photography / Kathryna Hancock