Why is starting a fitness program a situation that
requires a preventive health screening?

B/c they must be healthy enough to participate in physical activity and they must perform at their own health-levels.

Explanation:

This makes sense because you need to check whether your body is able to stand up to the fitness so that you don’t hurt yourself.

it's false.

"every person has their limitations which prevent us from accomplishing something. some are better than mathematics for example and some are worse. those people who are worse might never be able to become mathematicians, but that does not mean that they would not be great at doing something else."