There is literally a army of children who are trained for Olympics and nothing else from childhood to adult, funded by Communist party. the athletes we see on the grand stage are tip of the iceberg hundreds of rejectes become permanently crippled and without any education they are not even qualified enough to find a job. Most of them do hard labor to fend off for themselves.
Learned that from Hollywood movies, right? Even the old soviet system couldn't work that way.
There is no Chinese family will allow their kids to grow up without any education.
The system (in my age 1980s) used to work like this: the coaches of regional sports centers came to school to check the children (generally >7). They would make offers to those with potential. If the families accept it, their kid will attend the
part time training while continuing their education in the schools. If the kids still stay in training when they are 15, which mean they must have won some children level contests, they need to make decision whether they want to be a professional athlete or enroll for high school because from this stage, the training will become full time (education become part time). This is the critical time, the major career risk occurred in the following stage, the training level move up, the injury risk and competition will increase dramatically, If you survive during this stage and become a member of province team, you will have a bright future. If not, you can have following opportunities:
1. If you are smart, you can go back to high school to continue your education;
2. If you are good at communication, you can apply for some training courses to be a low level coach or phyiscal education teacher of schools;
3. If you are really dumb, you will be arranged to be a worker in factories (very good work in last 80s).
Today, they have even more opportunities: fitness coach, sport course teachers, private coaches, etc, etc.
Is there anyone end up as hard labors? Well, there is, but very few, generally those have no brain, no good personalities.
Remember: China is a society of relationship, after 10 years life in sport career, you should have built relationships with quite a lot of people. If you still end up in a miserable life, generally speaking, you only get yourselves to blame (except those get injuries that not suitable for any work, such as blind, or full body disability).