In addition to dumbbells, barbells are also the most used equipment in fitness. I believe everyone is familiar with the movement of barbell bending over rowing, because this movement is the movement we use the most when exercising the back muscles. The advantage of the barbell movement is that it can combine the muscles on our body to exercise, just For example, the barbell bent over rowing action, when we do this action, not only the latissimus dorsi, but the entire back muscle will exert force. http://www.luchfitness.com/free-weight/barbell/