Stand facing a cable machine with a parallel bar attachment set at chest height. Grasp the handles with a neutral grip and step back slightly. Keep your chest up and core braced. Pull the bar toward your upper chest by driving your elbows outward and squeezing your rear delts. Slowly extend your arms back to the starting position under control and repeat.
Log your cable rear delt row (parallel bar) sets in 1RM.fit and watch your estimated 1RM update automatically as you get stronger.