Training practices, speed and distances undertaken by Thoroughbred racehorses in Victoria, Australia.

Summary: Background: Musculoskeletal injuries (MSI) in racehorses are commonly due to bone fatigue, a function of the number of cycles (strides) and the magnitude of load applied to the limb. These parameters can be estimated using speed and distance, with greater than 6000 m/month at a gallop (>14 m/s), in combination with canter distances greater than 44,000 m/month, reported to increase fracture risk. Despite their importance, there are limited data on the distances and speeds horses are exposed to during training. Objectives: Estimate training volume at different speeds undertaken by Australian Thoroughbred racehorses. Study design: Cross‐sectional study. Methods: Registered trainers (n = 66) in Victoria, Australia were surveyed. Questions were designed to assess the full training workload from initial pre‐training to training performed to achieve and maintain race fitness, as well as information on rest periods. Descriptive analyses were stratified by trainer‐ and horse‐level factors, with assessment of variance within and between groups. Cluster analyses were used to identify similar workload intensity groups. Results: Horse‐level factors (age, targeted race distance) were associated with workload (younger<older, sprinters<stayers). Trainer categorisation did not influence workload, but there was significant variation in volume of total gallop exercise between trainers (median gallop distance 8000 m/month [IQR 6400–12,000]). Cluster analyses identified four workload programmes (medians): low‐intensity (4800 m/month), medium‐volume (8000 m/month), medium‐volume with a higher proportion of high‐speed workouts (12,800 m/month) and high‐volume programmes (19,200 m/month), with 23, 50, 17 and 9% of trainers predominately training racehorses under each of the respective programmes. Horses 3‐years and older were rested twice yearly for 6.3 (95% CI 5.7, 6.8) weeks, with more experienced trainers resting horses for shorter periods (P = 0.03). Main limitations: Possible selection bias, subjective reporting of workloads by trainers. Conclusions: Australian Thoroughbred training programmes include high volumes of galloping with more than half exceeding previously reported risk levels for MSI. [ABSTRACT FROM AUTHOR]