In fact, high and low are ineffective, just making yourself uncomfortable. As long as it's suitable ~ The following is what I saw in Weibo ~

How do office workers who work hard all day lose weight? 1. Sit in a chair, slowly lift your legs, put your hands gently on your lower abdomen, exhale slowly, and tighten your lower abdomen at the same time. When you receive the tightest breath in your lower abdomen, you will spit it out at the same time, and then slowly start inhaling. It's simple. 2. Sit with your back straight in 2/3 of the office chair, put some books under your feet, put your toes on the books, then stand on tiptoe and press your heels backwards to increase the strength of your calves and abdomen as much as possible. This feeling is effective for a long time. Are you sitting in a chair provided by the company? I bought it myself.