Stride Rates of Quarter Horses and Thoroughbreds During Races of Short and Classic Race Distances

Abstract

IntroductionRacing Quarter Horses (QH) typically compete at shorter distances and faster speeds than Thoroughbreds (Tbred). The two components of speed are stride rate and stride length. The hypothesis of this study is that racing QH have greater stride rates than Tbreds, and that stride rate decreases as distance increases, even within breed.MethodsFive runnings of sprint and classic distance stakes races for both QH (Texas Twister Stakes, 100.6 m; Champion of Champions, 402.3 m) and Tbred (Breeders′ Cup Sprint, 1,207.0 m; Breeders′ Cup Classic, 2,011.7 m) contested from 2008 to 2012 were obtained and viewed by five individuals. Individuals watched each race three times (in slow motion when needed) and the average number of strides per second taken by the winning horse was calculated. Using the PROC Mixed Procedure of SAS, the averages from the five individuals were used to compare differences between breeds, and between distances within a breed. The stride rates were also used to determine average stride length by factoring in length of each race.ResultsThe average stride rate was greater for QH than for Tbred (2.88 vs 2.34 strides/sec; P<0.0001). Additionally, stride rate decreased (P<0.0001) as distance increased (2.96, 2.81, 2.45, 2.23 strides/sec, respectively). Stride length was longest in the Tbred races and shortest in the 100.6 m QH race (P<0.0001).ConclusionsThe Tbred stride rates reported here, and associated respiratory rates, have been previously reported and are remarkable. However, QH rates are nearly 25% greater. The associated rapid acceleration and deacceleration of the lower limb and quick breathing rate may have implications for skeletal and respiratory soundness.Ethical Animal ResearchNo animals were used in this study and all information was obtained from previously conducted races for which video was publicly available. Sources of funding: Michigan State University and MSU AgBioResearch provided funding for support of investigators conducting this study. Competing interests: none.