Jitter is the whole body trembling initiated by itself. The basic posture is chest, standing, eyes slightly open, feet shoulder-width apart. Relax the whole body, eliminate distractions, and start the muscles and internal organs of all parts of the body to tremble with the heel and knee as the axis. The frequency and time of jitter can vary from person to person. Generally, it takes 20 minutes, and the longest is no more than half an hour. This kind of "shaking power" action is easy to learn and can be done anytime and anywhere. So many people who benefit from shaking fitness have this experience: shaking three times a day can live for 99 years.