Numerous scientific studies have shown that horses that make their first start at two actually race longer and are at decreased risk for injury throughout their entire careers. Data accumulated has consistently demonstrated that races restricted to two-year-olds have a lower rate of injury overall than races for older horses.

This is due in large part to the way bone adapts and remodels itself in response to the job it is being asked to do. Just as girls who participate in weight-bearing exercise at an early age are at decreased risk for osteoporosis and pathologic fracture later in life, so, too, horses whose skeletons have the opportunity to adapt and remodel to race training early in their career develop stronger, healthier bone.