As with human athletes, horses’ legs and hooves withstand great forces when the hoof contacts the ground, especially because horses weigh more than half a ton. And when a horse is moving at speed or turning, those forces increase, whether they’re competing on grass or an all-weather sand surface.

Producing the perfect sand footing for arena-based equestrian sports has become an exact science, with a complex layering system ensuring the best surfaces on which the horses perform, whether that’s for dressage or jumping.

The Olympic footing at the Baji Koen Equestrian Park in Tokyo–with the same composition on the main field of play and all the training arenas–is top-quality sand mixed with roughly 1.5% of polyester textile fibers. The sand provides impact firmness and grip, and the fibers provide cushioning, elasticity, and responsiveness.

“Sand is the most important ingredient in footing, and then the textiles and fibers are like the spices in your soup,” said Oliver Hoberg (GER), the person in charge of the arena surfaces.

Keeping that mix right and maintaining the footing is part of his daily routine, which involves dragging (raking) and watering; but the balance needs to be expertly monitored so the surface allows for optimal performance and horse safety.

Hoberg works in close cooperation with Fédération Equestre Internationale (FEI) footing expert Lars Roepstorff, DVM, PhD, of the Swedish University of Agricultural Sciences. Roepstorff is the scientist behind the footing and, in partnership with Hoberg, conducts daily checks on all the Olympic equestrian park arenas with a “mechanical hoof” originally created for testing racetrack surfaces. The hoof, which has now been adapted for the different equestrian disciplines, mimics the load placed on the horse’s leg and hoof when performing a dressage test or landing over a fence, whether that’s on sand or grass.

“Special sensors measure both horizontal and vertical forces as the mechanical hoof hits the ground, and those sensors measure the response from the ground so we can actually measure what the horse feels when it jumps on the surface,” Roepstorff said. “The footing is absolutely crucial, both to performance and to the health of the horse, and the different functional properties of the footing will affect how the horse performs.”

Those functional properties allow for “tuning” the surface, depending on the sport. But the only way to produce perfect footing is through maintenance that ensures uniformity throughout the arena.

“The footing is only as good as the level of maintenance,” Hoberg said. “In fact, maintenance is just as important as the type of surface used in the arena.”

With the correct level of maintenance, modern all-weather footing lasts up to 20 years, so there’s a post-Games legacy plan—all the arenas will remain in-situ when the venue is handed back post-Paralympics to its owners, the Japan Racing Association, so they can continue to be used for future equestrian sport.

But for Tokyo Games’ time, the right blend of footing, monitoring, and maintenance will provide the supremely fit Olympic equine athletes with the optimal stage on which to produce their peak performances.