Direct arm training of the upper arm muscle on the front side above the elbow not only provides visual and aesthetic development but also effectively strengthens one of the most frequently used everyday muscles. The isolated strengthening of the two-headed agonist to the three-headed arm extensor muscles can protect against injuries in the elbow joint. Furthermore, the exercise provides fundamental strengthening for strength training with heavy weights. The main function of the muscle is to rotate and flex the forearm ("curl").