I guess you can call that person an athlete.
You would call them a sports addict.
sports addict
You would call a person who plays the French horn a "hornist."
An athlete
An Athlete
I would call them a "Fanatic" or "Super Fan"
A "harmonicanist" is what a person who plays the harmonica is called.
A person who plays in movies is a actor or an actress
PianistA pianist is a person who plays the piano.
a person that plays a cello is called a cellist
You Call Them A Pianist.
Such a person is a Violinist.