Locomotory Profiles in Thoroughbreds: Peak Stride Length and Frequency in Training and Association with Race Outcomes

Abstract

Racehorses competing in short (i.e., ‘sprinters’), middle- or longer-distance (i.e., ‘stayers’) flat races are assumed to have natural variation in locomotion; sprinters having an innately shorter stride than stayers. No study has objectively tested this theory. Here, racehorses (n = 421) were categorised as sprinters, milers or stayers based on known race distance (n = 3269 races). Stride parameters (peak length and frequency) of those racehorses were collected from prior race-pace training sessions on turf (n = 2689; ‘jumpout’, n = 1013), using a locomotion monitoring device. Pedigree information for all 421 racehorses was extracted to three-generations. In training, sprinters had a shorter stride of higher frequency and covered consecutive furlongs faster than stayers (p < 0.001). Relatively short or longer stride did not predict race success, but stayers had greater race success than sprinters (p < 0.001). Peak stride length and frequency were moderately heritable (h2 = 0.15 and 0.20, respectively). In conclusion, differences in stride were apparent between sprinters and stayers (e.g., shorter stride in sprinters) during routine training, even after accounting for their pedigree. Objective data on stride characteristics could supplement other less objectively obtained parameters to benefit trainers in the appropriate selection of races for each individual racehorse.

Cardiovascular Fitness and Stride Acceleration in Race-Pace Workouts for the Prediction of Performance in Thoroughbreds

“…Hard gallop and jumpout sessions were 'race-pace' and speed (~60 km/h), corresponding to previously reported benchmark data (i.e., 10-12 s/200 m or furlong; [11,15]). Heart rate was at its peak (~200-210 bpm), and peak stride length and frequency were similar to previously reported race efforts [15,18].…”

“…Any training data were excluded if the date was ≥60 days before any race. To determine if training data predicted race success, race performance was categorised binomially as win or not, as previously described [15]. Model fit and significant variables included as fixed effects were assessed using backwards stepwise regression; that is, they were included if univariable analysis suggested importance in the model (p ≤ 0.10).…”

“…A tracking device (the 'Equimetre™', Arioneo, Ltd., Paris, France) was fitted to the girth prior to training by persons accustomed to using the device, as previously described [17]. The device recorded locomotory parameters (peak stride length and frequency) along with speed (by GNSS) and cardiovascular parameters (HR and HR recovery at 1 min after exercise), as previously described in detail [11,15]. Prior to this study, trainers had previously integrated the use of such trackers into the training regimes for each horse.…”

“…In this study, race class was recorded as follows: Group 1 (n = 93 of 3810 races, 2.44%), Group 2 (n = 73 races, 1.92%), Group 3 (n = 143 races, 3.75%) and Listed (n = 182 races, 4.77%), whereas all other races were manually labelled as Uncategorised (n = 3289 races, 86.3%). Race distance was known from http://www.racing.com (accessed on 18 January 2023) and was classified as a 'Sprint' race < 1600 m (n = 2246 races, 77%), 'Miler race' 1601-2500 m (n = 521 races, 18%) or 'Stayer' race' > 2501 m (n = 138 races, 5%), as previously described [15]. From the finish position, where available (n = 54 had no finish position recorded), the proportion win (n = 608 occurrences) or lose (n = 3148 occurrences) could be calculated.…”

Horse and donkey parasitology: differences and analogies for a correct diagnostic and management of major helminth infections

“…The domestic horse ( Equus ferus caballus ) and the Przewalski's horse ( Equus ferus przewalskii ) belong to the first clade (caballine horses), while zebras and wild asses belong to the other 2 clades (non-caballine horses) (Cucchi et al ., 2017 ). The modern horse has been intensely raised and selected (kinship) for their athletic potential focusing on morphological parameters of body weight (BW), withers height and also sports performance (Brown-Douglas et al ., 2009 ; Schrurs et al ., 2022 ; Dall'Anese et al ., 2023 ).…”