There is also practicing biceps brachii. When standing, you can put one foot on one side of the puller to shake hands, and at the same time hold it with your hand for arm flexion and extension, so as to keep your body from shaking. You can use your mind to pull the retractor with the strength of biceps brachii, and the weight depends on your personal strength. You can also practice triceps brachii Fix one side of the stretcher on the door frame and adjust the height according to your height. Hold the other side with your hands, fist down, arms close to your body. Slowly extend the stretcher downward, pay attention to the big arm, only move the small arm, let the triceps brachii fully tighten, and then play it back slowly.