Jockeys must be light to ride at the weights which are assigned to their mounts.
There are horse carrying weight limits, that are set by racing authorities.
Though there is no height limit for jockeys, they are usually fairly short due to the weight limits.
Why do jockeys need to be small?
The point is to try to equalize the field by putting more weight on faster horses and less on slower ones. In order to be hired, jockeys have to be very light. The only way to make a person light is to make them short, slim and light-boned — that’s why jockeys are short.
Why are jockeys stirrups so short?
By, in effect, floating above his mount, the jockey saves the energy the horse would otherwise expend to shove him back up after each bounce down into the saddle. Doing this is “very hard work,” says Wilson, because the rider uses his legs in their short stirrups as springs or pistons.
Do jockeys stunt their growth?
Some, such as jockeys, instead go to extreme lengths to stunt their growth — sometimes down to the size of a pre-pubescent child. In an industry where just a few extra pounds can rule you out of a multi-million dollar race, jockeys are put under enormous pressure to meet miniature weight requirements.
Why do jockeys stand up at the end of the race?
When a jockey needs to urge the horse to go faster, he assumes a lower crouch. After the race, the jockey stands so that the horse will slow down his momentum.