An 'athletic' heart is a heritable characteristic linked to good endurance performance, researchers confirmed. | Photo: Anne M. Eberhardt/The Horse

“An ‘athletic’ heart is a heritable characteristic that’s favorable for performance in endurance,” said Céline Robert, PhD, DVM, professor and researcher at the National Veterinary School of Maisons-Alfort and researcher at the French National Agricultural Research Institute in Jouy-en-Josas, France.

Unlike Thoroughbred racehorses, Arabian and Arabian-cross endurance horses start training at around age 4 or 5 and reach high-level (160-kilometer) races starting at about 8 years old. “If you have to invest eight years of training and maintenance into a horse before you know if you’ve got a champion, you want to be sure you’re starting off with the right horse,” Robert said.

But success doesn’t always pass down through the genes. That’s why Roberts and her fellow researchers set out to determine what genetic factors affect performance and how heritable they are