Stand up straight, with your feet shoulder-width apart, your hands reaching to your back and waist, clenching your fists with your fingers, and pushing out as far as possible (thumbs down, palms back as far as possible).

At this time, you can see from the mirror that the meat on your back has formed a Sichuan character (there are more friends with more meat than Sichuan characters)

Hold this position for more than five minutes. As long as you keep practicing every day, your thick back will become thinner.

This action can also relieve the common shoulder and neck pain of white-collar workers.