Some things require actual practice to judge.
QiGong for the first month is all effort.
Then after 90 days one can objectively judge what has gone on, changed in life.
After 1000 days, one can be sure of the benefits.
Eight Pieces of Brocade requires full attention, subtle effort, and is suitable for those with injuries to the back.
Type Li Ching-Yun in your search engine to see what one practitioner experienced.