I practiced for nearly half a year more than 30 years ago, when I was 19 years old, and the effect was quite good. After about three months, I felt a sense of qi in my abdomen and hands at Laogong point. For half a year, my abdomen usually beats from time to time, and I accidentally sprained my hands and feet, so I was lucky at night. I was too young to persist, and I couldn't practice this skill in the same room or windy place, so it was difficult for young people to persist in my abdomen.