Skeletal injuries–those involving bones and joints–are a major concern for all athletic horses. The usual outcome of these injuries is a lameness problem that hampers a horse’s training and competition program or, in some cases, is so severe that the horse can no longer be used for any athletic purpose. In fact, by a wide margin, musculoskeletal injuries are the most common cause of poor performance and wastage (where wastage refers to a loss of training days, either temporary or permanent) in the equine industry.

For this reason, researchers, veterinarians, and horse owners are keenly interested in developing training programs and other preventive methods that help minimize skeletal injuries, thereby improving the health and well-being of the athletic horse. Fundamental to this quest for a decrease in the rate of skeletal injuries is an understanding of how bone and cartilage adapt to the rigors of exercise and how different training methods and dietary practices influence these processes.

In this article, we’ll review the basic elements of bone development (modeling and remodeling), how exercise and physical conditioning modify these processes, and whether different training methods and diets can modify bone strength–recognizing that current knowledge in regard to this last question is fairly limited and there is a need for a great deal more research in this area.

Bone Structure and Function

The skeleton provides structural support for the body, protecting internal organs (e.g., the ribs protect the heart and lungs in the chest) and housing the bone marrow, where red and white blood cells are produced. Bone also functions as the body’s reservoir of calcium and phosphorus. Although you might view bone as a static, rigid organ, it is actually a dynamic tissue that is constantly undergoing change, mostly in an attempt to maximize its strength in the face of changing demands