By Céline Gualde
The Thoroughbred model differs greatly depending on their specialty and preferred distance. A bit like in athletics: a sprinter with a powerful physique would have a hard time coping if they started a marathon. While horses running 1,000-1,600m are generally stocky, dominated by their muscular hindquarters, 2,400m Thoroughbreds have a slenderer physique and beautiful shoulders that seem to propel them forward. Histological studies show that these morphological differences are reflected even in the muscles of Thoroughbreds. Richard Corveller, veterinarian at the Meslay du Maine equine clinic, explains: «Muscle fibres determine the aptitude of horses. Those of a sprinter contract quickly but for a short time, unlike those of a stamina horse. Their heart itself has different capacities.”
This physical potential is inherited, and the breeder’s job is to guide and refine it according to the desired goal. Take the case of Sottsass, winner of the 2020 Prix de l’Arc de Triomphe at 4 years old, after finishing 3rd in the previous edition. His own brother Shin Emperor will be at the start of the big race on October 6th under the Japanese banner. Their dam Starlet’s Sister (Galileo) only ran four times, including three over 1,500-1,600m, without winning. But it was a constrained choice for the filly’s connections. Alain de Royer-Dupré, who trained her, confides that Starlet’s Sister had Lyme disease, which dulled her physique. However, stamina horses must have solid health because it is a key element to withstand the length of the effort. Leo’s Starlet, Starlet’s Sister’s own sister, also trained by Alain de Royer Dupré, won the Prix Cléopâtre, Group 3 over 2,100m. Henri Bozo, breeder of Sottsass at Ecurie des Monceaux, chose the great sire Siyouni for Starlet’s Sister so that he would bring «thickness and speed». A paying choice since it gave Sottsass, endowed with an acceleration capable of crucifying his opponents in the Arc.
In addition to genetics, other factors come into play to build up stamina. Richard Corveller puts the temperament of the horses first: «To withstand the 2,400m they must oxygenate well and therefore be sufficiently relaxed, well in their head. A 5f horse produces an anaerobic effort, which can be done in apnoea. But over longer distances, psychological capacities are essential.” One might argue that mental strength is also inherited, at least in part. But a 2,400m horse is patiently forged, every morning in training. Alain de Royer was a follower of «progressive cantering» which teaches the horse not to panic and to gradually tense up to finish by bending its back like a bow. «It’s a lot about career management,» confirms Henri Bozo. “To last, horses must be preserved at 2 years old. Their skeleton needs to mature. Some trainers are more specialized and more gifted at letting the potential of stamina Thoroughbreds express themselves.” This was the case of Alain de Royer, who confides: «The daily work of the horse is essential. When I trained the Aga Khan horses, they all had the same program at 2 years old and then we specialized them according to their aptitudes. If we take the example of Zarkava, she started over 1,600m at 2 and 3 years old before being extended on the Prix de Diane (2,100m in June of her 3 years old), the Vermeille (2,400m in September) and the Arc which she flew over in October.” The filly entered the stud undefeated in seven races, including five Group 1, «thanks to her final burst of speed» according to her trainer.
The current market trend is to produce horses that can be exploited more quickly. «In the last twenty or thirty years, we have created a new breed of Thoroughbred in France: the two-year-old that is fast and exploited early,» says Freddy Powell. The opposite of the Arc horse, which is patiently shaped, from its birth to its peak three to five years later. The economic aspect is largely responsible for this evolution, and one may wonder if, in the long term, the classic distance will remain the premier distance...
The last ingredient to obtain one of these mythical stamina horses that enter the legend, after genetics, mentality and training, is therefore the owner. He must dream of the Arc and the Epsom Derby, and have the financial capacity to offer his horse, in addition to dream genetics which is in itself a fortune, this precious and incompressible learning time which will perhaps lead him to the firmament.
Stayers have big hearts
The stallion Eclipse, true «Adam» of Thoroughbreds since he is almost systematically found in the pedigree of contemporary horses, was endowed with a huge heart. The autopsy of the champion born in 1764 revealed a heart weighing 6.4 kilos when the usual weight of a racehorse’s heart varies is about 5 kilos. The chests of great performers such as Phar Lap and Secretariat also housed a huge heart. Various contemporary scientific studies demonstrate a correlation between a horse’s preferred distance, its degree of performance and the size of its heart. The left ventricle, which returns blood previously oxygenated in the lungs to the body via the aorta, is the main object of studies. The end-diastolic volume (volume of the heart when it is filled with blood) and the systolic ejection volume (volume of blood returned to the body when the heart contracts) are higher in horses running over 2,000m and more than in sprinters. The latter generally have a slightly thicker heart wall and slightly less voluminous cavities than stamina horses. An English study conducted in Cambridge and Newmarket in 2005, involving 483 Thoroughbreds in training, showed that the volume of the left ventricle of the heart was 8 to 16% larger in hurdle horses compared to those running flat over short distances. The study also concludes that the hearts of horses evolve physically under the effect of training in order to better adapt to the effort required. The role of the trainer in the «formatting» of the young galloper is therefore a key element.
Mother nature’s surprises
If genetics is the basis for directing horses towards a certain distance, there are however exceptions that prove the rule. All the stakeholders in the production of this article cited the colossus Persian King, 1.70m at the withers, now a stallion at the Haras d’Etreham. Neither his physique nor his origins predestined him to stay the distance. He is a son of Kingman and Pretty Please by Dylan Thomas. “His father is an excellent stallion for producing 1,600m horses, it’s a typical American speed horse origin with Invincible Spirit behind. His damsire Dylan Thomas was a stamina horse but is not known to improve the breed,” analyses Richard Corveller. Excellent and tough, Persian King, trained by André Fabre, ran twelve times for seven wins and five places. He won Group 1 over 1,600 and 1,800 meters and achieved the unusual performance of chaining a victory over the 1,600m of the Moulin de Longchamp in September 2020 with a third place over the 2,400m of the Arc exactly one month later. «He had versatility as they say in English: an ability to accelerate over all distances,» analyses Freddy Powell. For Alain de Royer, «He was a horse with a magnificent turn of foot, he didn’t really stay the distance but did it on his class» The two agree that Persian King’s aptitudes are «A genetic oddity but above all a great training performance”. Alain de Royer also likes to quote the stallion Sendawar (Priolo). “I started him over 2,000m at three years old because he was very cold in the morning,” recalls the trainer. He won his maiden over 2,000m, then was beaten by Montjeu over the 2,100m of the Prix Greffulhe. Finally, he was a 1,600m horse, he won three Group 1s over this distance and ended his career with a victory in another Group 1, the Prix d’Ispahan over 1,850m. You have to be wary of horses that sleep in the morning because we tend to start them over too long! » Solow, Freddy Head’s famous gelding, who wore the Wertheimer silks, is another curiosity. Freddy Powell recalls that he was born to run over long distances, being the son of Singspiel who excelled over 2,000m and more and of a mare who had her best performances
From milers to jumpers
Yannick Fouin, based in Maisons-Laffitte, is one of the best jump horse trainers in France, but he does not disdain flat racing. He likes to convert 1,600m horses to jumping if their temperament allows it: «These horses can win over 3,500m over jumps and are even often the best. In a race without pace, a short-distance flat horse will beat everyone thanks to its finish. The key is to hide the effort from it, to let it «sleep» at the back to preserve its final burst of speed. It’s a way of breaking the distance, another being to liven up the race with a false pace. The faster a race is, the more the distance matters.”
According to Mathet...
Excerpt from Thérésa Revay’s book dedicated to trainer François Mathet, in which she quotes the great theorist of breeding, also Mathet’s biographer: «According to him, a horse’s ability to cover a certain distance is innate and it can neither be modified nor improved by training. If the horse is able to stay a long distance, it is because it has the right temperament for it, the right lung capacity and the appropriate heart rate, and not because training has led it there. Mathet laughs when he hears that a horse has been «lengthened» or «shortened» in anticipation of such and such a race. If a horse is victorious over an unsuitable distance, it is only because it is of a superior class to the others and not because of a particular training method.”