Stand with feet shoulder-width apart and hinge forward at the hips with a straight back and slightly bent knees. Hold a resistance band (anchored under your feet or to a stable point) with both hands. With a slight bend in your elbows, pull the band outward and up to the sides until your arms are roughly level with your shoulders, squeezing your shoulder blades together. Slowly return to the start under control.
Log your resistance band bent over rear delt fly sets in 1RM.fit and watch your estimated 1RM update automatically as you get stronger.