Jockey
A jockey is a person who rides horses in horse races. Most jockeys have to be under a certain weight and/or height, so they would not be too heavy on the horse.
Jockey Media
A jockey riding in a hurdle race
Toulouse-Lautrec - The Jockey (1899)
The colours worn by jockeys when racing horses owned by Cyrus S. Poonawalla