Even if you are good at sprint and long jump, you can only go to sports schools or amateur sports schools run by institutions of higher learning such as the Institute of Physical Education, which is equivalent to technical secondary schools. A well-run sports school may give you a secondary school diploma when you leave, and then you can take this diploma to take the college or university exam to continue your study.

If your athletic ability is really outstanding, you can find a high school with a good training team in this field, and they may recruit you. But usually a few months ago, you have to take the special student exam in this field, and after you get the special student qualification, you will be admitted to a lower score.

If your academic performance is too poor, your sports ability is not outstanding in the whole region. To be honest, high schools generally won't accept you. (I am a high school PE teacher)