Most jockeys first learn to handle horses as exercise boys or girls, riding in morning workouts. Jockeys are usually about 5 ft (1.5 m) tall and weigh about 110 lb (about 50 kg). They begin their jockey careers as apprentices, receiving weight allowances until they have won a stipulated number of races. Jockeys wear distinctive colored and patterned shirts and caps, called silks, that identify their horse’s owner. They may ride for a particular owner or accept whatever mounts trainers offer. Jockeys are paid a fee for each horse they ride as well as a percentage of the purses their mounts win.

The most successful American jockeys of the 20th century included Eddie Arcaro, Bill Shoemaker, and Laffit Pincay, Jr. Shoemaker retired in 1990 with 8,833 victories, a record for jockeys, only to see Pincay surpass him in 1999. Notable British jockeys include Sir Lester Keith Piggott, Frankie Detorri and Dick Francis; the latter became a popular author of mystery stories with racetrack settings. Although women were not granted jockey licenses until the 1970s, the Americans Robyn Smith and Julie Krone achieved considerable recognition.

Trainers prepare horses for races and maintain the animals’ condition over the course of their racing careers. Trainers also select which races their horses will enter, taking into account such factors as the race’s distance and the quality of the competition. Like jockeys, trainers may be under contract to a particular owner or they may supervise horses belonging to several owners. Also like riders, they receive a percentage of purses earned.