athletics - athletic
Athletics consists of sports such as running, the high jump, and the javelin.
He has retired from active athletics.
Athletics is an uncount noun. You use a singular form of a verb with it.
Athletics was developing rapidly.
Note that the American term for this is track and field.
She never competed in track and field.
Athletic is an adjective. It can mean ‘relating to athletics’.
However, when you use athletic to describe a person, you mean that they are fit, healthy, and active. You do not mean that they take part in athletics.
...athletic young men.