Sit at the lever machine with your chest against the pad and grasp the single handle with one hand. With a slight bend in your elbow, pull the handle outward and back in a smooth, controlled motion, focusing on engaging the rear shoulder and upper back muscles. Pause briefly at the peak contraction, then slowly return to the start. Repeat on the other side, keeping the torso still throughout.
Log your lever side seated single arm rear delt fly sets in 1RM.fit and watch your estimated 1RM update automatically as you get stronger.