07/08/2014 5:57PM

Bramlage: Short, high-intensity workouts might be best

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LEXINGTON, Ky. – Horses need regular intervals of rest or “reduced exercise” during training in order to build bones strong enough to handle the loads encountered during racing, according to Dr. Larry Bramlage, the renowned equine orthopedic surgeon.

In a frequently technical one-hour presentation at the Safety and Welfare of the Racehorse Summit on Tuesday, Bramlage presented the results of studies and clinical research on bone growth showing that a horse’s leg bones are best strengthened through short, high-intensity loads followed by brief periods of little to no stress, to allow the bone to “remodel.” The short, high-intensity loads equated to approximately one furlong of high-speed work, Bramlage said.

Bramlage’s presentation introduced questions about how most modern Thoroughbreds are trained, typically by using four- to five-furlong high-speed workouts spaced approximately every five days in the weeks leading up to a race, along with daily gallops. Though he did not provide recommendations for an optimal training schedule, Bramlage’s research appeared to indicate that some common perceptions of training may need to be re-examined in light of ongoing research shedding new light on the physiological weaknesses that lead to injuries.

For instance, Bramlage said that “galloping a horse up to fitness” – using two-mile, relatively strenuous gallops to build muscle and stamina – might be counterproductive because it can result in too much stress on bones. In addition, Bramlage said “walking the shed row” or stall rest to get a horse to recover from minor injuries also was counterproductive because horses need some stress on bones to signal the structures to repair properly.

In recognition of all the factors involved, Bramlage said developing a training regimen to maximize bone strength is a very difficult balancing act, and he cautioned that many horses respond to stress and exercise very differently.

"You have to do damage to make the horse's bone stronger, but doing that right is like using a blowtorch to dry clothes,” Bramlage said. “You have to get it exactly right.”

The Tuesday presentation rehashed several points that Bramlage presented approximately a year and a half ago at the fourth Safety and Welfare of the Racehorse Summit, a semi-annual conference put on by the Grayson Jockey Club Research Foundation held at Keeneland. Bramlage, who works at Rood & Riddle Equine Hospital near Lexington, is one of the racing industry’s foremost experts on musculo-skeletal injuries.

During the Tuesday presentation, Bramlage also stressed that horses need to be exercised regularly as 2-year-olds in order to build strong bones, citing the physiology of bone growth and studies showing that horses who run as 2-year-olds suffer far fewer catastrophic injuries than horses that do not run at 2. Many animal-rights organizations, and some racing insiders, have criticized the racing industry for training and running horses at 2 despite the data and the physiological understanding of bone growth and remodeling.

Bramlage also recommended that racetracks “entertain” the idea of allowing for both left-handed and right-handed training, as studies seem to suggest that horses’ musculoskeletal systems would benefit from the variation, he said. He also said it would be reasonable for trainers to modify the gaits that their horses use and require them to perform different exercises than just running around the track in order to allow for more complete growth of bone to handle different and unexpected stresses and loads that can arise during a race, such as when a horse takes a “bad step” on the track.

But Bramlage also said research has been unable so far to divine a “magic number” of furlongs a horse should train or race in a given period to avoid injury. He said a recent analysis of two populations of horses, one that required surgery for a leg injury and one that did not, showed that both populations ran essentially the same distance in racing and training, yet one population suffered injuries while the other did not.

As a result, Bramlage said, there’s no way yet to use distance worked to predict a fracture in a racehorse, but he said he suspects the speed or intensity of the distance raced and trained likely plays a role. Bramlage said he expected to pursue research in that direction in the future.

“I suspect it has a lot to do with not how often you race, but with what intensity you load the skeleton,” Bramlage said. “There is a limit. We don’t really know what that limit is. That’s one of the things we need to figure out better.”