This exercise is used to work the muscles of the back and will prevent cheating like a normal bent over row.
Begin by adjusting a bench to a 30 degree angle. Lay face down on the incline bench, and reach to grab a barbell with a double overhand grip. A spotter is helpful here to hand the barbell to you. Next, pull the barbell towards your chest by driving your elbows straight back. Continue this motion until the barbell touches the incline bench. Squeeze your back muscles at the top and hold the contraction for a second. Slowly return the barbell to the starting position. Repeat this motion until you have completed your set.
This movement should feel similar to a bent over row. Make sure to keep your chest flat on the bench, and do not allow it to swing off of the bench.
This exercise can also be done with dumbbells.