The upper arm has many main muscles, mainly the biceps on the front side of the upper arm, the triceps on the back side, the deltoids on the outside, and also the wrist dorsiflexors and wrist flexors on the forearm. Generally, according to their own physique to choose the right weight of dumbbells as a weight, holding dumbbells with both hands to do the flexion of the elbow action mainly exercise biceps, do the elbow action mainly exercise triceps, do the upper arm abduction action mainly exercise deltoids, do the wrist dorsiflexion action, is the movement of the wrist, mainly exercise wrist dorsiflexor, do the wrist flexion action mainly exercise wrist flexor. Exercise must follow the principle of gradual progress, maintain a moderate amount of training, can not be rushed to prevent muscle strains. Exercise to ensure a reasonable diet, give the muscles enough energy to meet the needs of the body.