1-Arm Dumbbell Row
The most basic and accessible but still effective unilateral upper body pulling exercise.
Support yourself on a bench with one arm and one knee to position your trunk approximately horizontal. Start with a dumbbell in your free hand and the arm extended completely and shoulder blade protracted. Row the dumbbell up by retracting the shoulder blade and pulling the elbow as high as possible—allow the weight to trail behind the elbow. Squeeze your upper back forcefully at the top of each rep. Return to a fully extended amd protracted position without rotating the trunk.
1-arm rows can be performed through the entire range of repetitions, from very low (3-5) with extremely heavy weights, all the way up to maximal rep sets of 30 or more. Like any exercise of this nature, many variations of rep and loading schemes can be used, from traditional sets of prescribed reps, to maximal rep sets, to rest-pause sets, etc.
The 1-arm row can be done perfectly strictly, or with varying amounts of body English depending on the desired effect. Slow eccentrics and pauses in the top can be added, and straps can be used for extremely heavy or high-rep sets as needed. The support position can also be modified to using only the arm, or to change the angle of the back.