LOUISVILLE, Ky. — As dawn broke over a clear Louisville morning, racehorses galloped powerfully down Churchill Downs’ legendary track, epitomizing their extraordinary elegance and strength. Beneath the watchful eye of Dr. Will Farmer, these massive creatures demonstrated the attributes that make them the stars of events like the imminent Kentucky Derby, where the focus will be on their exceptional athleticism and the growing body of research exploring the factors that contribute to their prowess.
Dr. Farmer, who serves as the equine medical director at Churchill Downs, notes that horses’ physical capabilities are rooted in their evolution as prey animals—traits that have served them since their survival in the wild. “Horses developed such skills as running to evade predators,” he explains. The forthcoming Kentucky Derby—one of horse racing’s premier events—brings both celebratory attention and scrutiny concerning the health and welfare of these animals, especially given past concerns over their treatment and safety. Tragic events like the deaths of 12 horses at Churchill Downs only heightened these discussions, pushing for improvements in the sport’s practices.
The bond between humans and horses has dramatically shaped history, facilitating advancements in agriculture, warfare, and transport. “Horses enabled humans to overcome biological constraints,” says historian Timothy Winegard. The powerful synergy between human innovation and equine strength created what he calls an “unstoppable alliance.”
The incredible abilities of horses are credited largely to their exceptional heart and lung capacities. An adult horse’s heart can weigh up to 12 pounds, a vast difference from the human heart. The legendary Secretariat, whose sweeping victories remain unmatched, was found to have a heart weighing more than 20 pounds. These hearts allow horses to reach heart rates as high as 240 beats per minute during peak performance, a rate significantly surpassing that of humans. Their lung capacity is equally impressive, capable of holding as much as 60 liters of oxygen—ten times that of humans.
A recent study in the journal Science unveiled that genetic mutations contribute to horses’ ability to manage high energy production incisively. Dr. Gianni Castiglione, associated with the study, explains, “Horses can deliver more oxygen to their muscles than even the most elite human athletes.” This capability results in an efficient energy output, bolstering their athletic performance.
In addition to those core biological features, other elements of a horse’s anatomy support its remarkable speed and power. Horses possess a reserve of red blood cells stored in their spleens, released during intense exertion to transport more oxygen through the bloodstream. Dr. Hilary Clayton likens this adaptation to a form of natural ‘blood doping.’ Their brains, designed to process sensory input swiftly, enable horses to respond with precision and speed without being hindered by fear.
However, these evolutionary adaptations also render horses vulnerable to specific risks, notably injuries incurred from the demands of racing. The impact absorbed through their thin legs can, over time, lead to strain and deformation. This reality has prompted changes within the racing industry, particularly after the spate of fatalities witnessed in recent years. New measures implemented at Churchill Downs, such as upgraded track equipment and enhanced veterinary oversight, represent efforts to safeguard the health and longevity of these magnificent animals.
The journey to becoming a champion horse entails more than just favorable genetics, with experts noting that factors like environment, training, and the bond with their riders play significant roles. Dr. Scott Bailey highlights that achieving peak performance from a horse comes from more than inherent talent—it involves careful nurturing and development on multiple levels.
While understanding what truly makes a Derby winner remains elusive, what’s clear is that every race brings a potential for unexpected triumphs and narratives, as horses of various backgrounds and pedigrees vie for the win. Dr. Farmer eloquently speaks to the magic of the Kentucky Derby: “You don’t necessarily have to be the top-bred horse to excel and leave a mark.”