Japanese researchers report in a recent study that applying structured exercise regimens early in horses’ lives can potentially alter the development of their tendons to benefit future athletic ability and limit tendon injury later in life. These results were based on the fact that exercise regimens didn’t appear to have deleterious effects on tendocytes, or tendon cells.

According to Alicia L. Bertone, DVM, PhD, Dipl. ACVS, from the Comparative Orthopedic Research Laboratory at The Ohio State University, "Tendon injuries are an important cause of wastage in athletic horses, particularly (when injuries occur in) energy storing tendons–such as the superficial digital flexor tendon (SDFT)–which act like springs to contribute to movement."

To determine if a structured exercise program imposed early in a horse’s life could improve the quality of developing tendons to limit exercise-related injuries later, a group of researchers from the Japan Racing Association Equine Research Institute divided 14 foals into exercise and control groups.

All foals were turned out on pasture for four hours per day, but horses in the exercise group received an additional period of treadmill exercise five times per week. When the horses reached 15 months of age, the researchers evaluated the microscopic structure, biochemical composition, and biomechanical properties of the SDFTs and the common digital extensor tendons (CDET–a positional tendon)