It is a book. The original text of Yang Yunfeng's diary is on Sina Blog.

Yang Yunfeng’s height-increasing diary mentioned the order of height-growing exercises: warm up, then jump, and then stretch.

The original introduction to the diary is as follows: Hello everyone, my name is Yang Yunfeng. I am 27 years old this year. I started to want to increase my height last year, and it has been almost a year now. I am writing this Yang Yunfeng’s magical height increase diary to share my own height increase process, hoping to help some friends increase their height.