Page 70 - March 2017

“We can help a horse with good training, but it is difficult to make a natural sprinter into a distance horse or vice versa.”
What is it about a horse that enables him to be a winner, especially on the race track? It takes a combination of strength, speed, good confor- mation, the “heart” and will to run, and sheer determina- tion. It all comes in a package that isn’t necessarily easy
to recognize in a foal or a young, untried adolescent just starting training or being evaluated at a yearling sale. Can he run? Will he be a sprinter or a distance runner? Every breeder of racehorses and every buyer at a sale are hoping to find that perfect combination.
The next question we should ask, then, is where is that horse’s sweet spot for distance.
Bill Casner of Flower Mound, Texas, has some observations about the traits and talents that differ between sprinters and distance horses. Casner has been working with racehorses all his life—both Quarter Horses and Thoroughbreds. He still breeds and buys some Thoroughbred racehorses, but also owns some good Quarter Horses that he uses for team roping.
“Some horses’ best distance is the quarter mile (440- yard) versus 350, and some will stretch out to 550, and some may run 870, as well. The basis of this question (the distance a particular horse can run) is mainly genetics,” says Casner. What a horse inherits for talent, conforma- tion, and muscle type makes the biggest difference in what distance he can run.
Some horses excel at continuous athletic effort because their muscles work aerobically, depending
on sustained oxygen supply. Others excel at quick bursts of speed, utilizing whatever oxygen and fuel is already stored in the muscle cells. This is the difference between a sprinter (anaerobic) and a distance runner (aerobic). Sprinting is an all-out effort for a compara- tively short period, while a distance runner must put forth sustained effort.
“Some Quarter Horses can almost run their race without even breathing. They can almost hold their breath that long! A horse generally takes a breath at every stride, in and out, as a natural action and because of the mechanics of the lungs. But some of the sprint- ing Quarter Horses can go into oxygen debt and sustain
their exertion during their run and catch their breath later. They can sustain shorter breathing patterns for that sprint,” he says.
There is also a difference in skeletal muscle fibers between sprinters and distance runners. Horses (and
Sprinting is an all-out effort for a comparatively short period, while a distance runner must put forth sustained effort.
Bill & Susan Casner won the 2010 Kentucky Derby with their colt Super Saver.
HORSES THAT CAN RUN LONGER DISTANCES
by Heather Smith Thomas
68 SPEEDHORSE, March 2017
EQUINE HEALTH