MADELEINE BRAND, host:
Race horses run faster than they used to. It's not because of better breeding or new training methods. No, scientists say it's new ways jockeys are guiding their horses using the laws of physics.
NPR's Jon Hamilton has more.
(Soundbite of racetrack)
Unidentified Man: And away they go.
JON HAMILTON: From the instant the starting gate opens, a modern jockey is working really hard.
Unidentified Man: Now (unintelligible) right there in second.
HAMILTON: During a race, a jockey's heart may exceed 180 beats a minute. Frankie Lovato rode more than 15,000 races before retiring a few years ago. He says all that exertion by the jockey is making it easier for the horse.
Mr. FRANK LOVATO (Jockey): While the horse is running underneath you, you're basically trying to be weightless on top of their back, and instead of inhibiting their rhythm and their stride, you're actually encouraging it with your upper body, with your arms.
HAMILTON: Now scientists have some data to back up that claim. Alan Wilson is a professor of locomotor biomechanics at the Royal Veterinary College in the UK. He's part of a team that was trying to figure out how much energy a horse uses to carry a jockey. As part of that effort, they began studying the history of horse racing. And they noticed that jockeys in the UK had radically changed their riding posture in the early 1900s. Instead of sitting upright in the saddle, they began to crouch and put their weight on the stirrups. Wilson says it was an American jockey named Tod Sloan, who developed the new style.
Dr. ALAN WILSON (Locomotor Biomechanics, Royal Veterinary College, UK): This guy Sloan was banned from riding in the U.S. and moved to the UK in 1897 and thought of riding horses in that way here. That style was quickly adopted across UK racing over the next five to ten years.
HAMILTON: And winning race times improved by five percent or more. Wilson says that suggests the new posture greatly reduces the effort required to carry a jockey. To find out, his team began using sensors to track the relative movements of horse and jockey on the track. Wilson says the sensors showed that while the horse moves up and down with each stride, the rider doesn't.
Dr. WILSON: The jockey is a bit like a person skiing down a mogul field. Their feet are going up and down, but their body is following a smooth path.
HAMILTON: The jockey is also compensating for the rocking motion of each stride. All that compensating reduces what a physicist would call inertial losses. And Wilson says that's why it's become easier for a race horse to carry a jockey than, say, a sandbag of equal weight.
Dr. WILSON: The jockey is standing up and using his legs like pistons to isolate himself from the movement of the horse. The horse has to support the jockey's weight, but doesn't have to move the jockey through the horse's movement.
HAMILTON: Wilson says there is a catch, though.
Dr. WILSON: It's really quite difficult to do. If you actually ride on a horse or ride a horse stimulator, it's actually got - involves quite a lot of balance and coordination 'cause you're standing connected by your feet to something that's bobbing along at 40 miles an hour.
HAMILTON: Even so, Frankie Lovato says jockeys have continued to find ways to ride more efficiently.
Mr. LOVATO: As time went on and we got into the '30s and the '40s, jockeys rode with shorter and shorter stirrups and found that it was a more effective way to make a horse run faster.
HAMILTON: And Lovato says in the past decade or so, they've begun to study digital images of races to refine their technique even more. They've also begun practicing on something Lovato invented called the Equicizer. It's an artificial horse that lets jockeys simulate the experience of riding a race. The new research appears in the journal Science.
Jon Hamilton, NPR News.