The person is called the loser.
"Keep your boasting till you've beaten," answered the Tortoise. "Shall we race?"
starter person
The person is usually called "the starter."
Because racist is for people who discriminate other people, so a person who drives a car is just called a race car driver.
A person who rides horses (mainly thoroughbreds) is called a Jockey
racism
Well, killing a race, religion, or group is considered genocide, so the person who coordinates this is called a genocidal.
A Pansexual
An award called the red lantern
Funnily enough, they are called a starter.
I can think of two, Ricky Carmichael and Chad Reed, as a matter-of-fact, Ricky Carmichael lapped James Bubba Stewart in a race, RC has beaten JBS many times.
The Pole Sitter. I believe they're called a "Flagman/person"