It is said that if you want to build a perfect figure, fitness really can't be done by weightlifting equipment and simple strength training. In view of the fact that the quality of domestic gym coaches is hard to compliment, we should pay attention to avoiding professional exercise. Division of arm muscles: The upper arm muscles surround the humerus and are divided into two groups. Front group: biceps brachii, coracoid brachialis and brachialis. Posterior group: triceps brachii and elbow muscles. Biceps biceps brachii and its starting and ending points: location: in front of the upper arm. There are two starting points: the long head starts from the supraglenoid tubercle of the scapula and has a long key, and the short head starts from the coracoid process of the scapula. Stop point: the tendon stops at the radial rotor and the aponeurosis stops at the forearm fascia. Barbell bending target muscles: biceps brachii, coordination muscles: brachialis, brachioradialis and forearm muscles. Starting posture: Stand naturally, palms forward, hands shoulder-width apart. During the whole movement, the two upper arms are always attached to the side, and the barbell is hung in front of the legs. Action process: inhale, with the elbow joint as the fulcrum, and the forearm bends the barbell into an arc from the front of the leg to the chest. After reaching the "peak contraction" position, pause for a while. Then, exhale and slowly return to the starting position with the tension of biceps brachii. Action essentials: always fix the two upper arms at one side of the body, and only let the forearm move. Don't touch the shoulder at the highest point, and don't touch the thigh at the lowest point, so that the biceps brachii always keeps a certain tension. Don't hold the barbell too tightly, otherwise it will cause the forearm muscles to be tense. Wrist and forearm should be kept on the same plane, and bending inward or outward is not allowed. Once the wrist is pulled in the bending process, the stress point will be dispersed to the forearm muscles, which will affect the practice effect. Don't shake your body back and forth, and spread the hard spots on your waist, which will also affect the practice effect.