Association of Thoroughbred Racehorse Workloads and Rest Practices with Trainer Success

Training workloads influence the risk of injury for racehorses, but veterinary advice to trainers is unlikely to be followed if it is associated with reduced racehorse performance, and thus their profitability. We therefore investigated whether the intended training programs for healthy horses was associated with the rate of wins, places and prizemoney earnt per start for Thoroughbred trainers in Victoria, Australia. Intended training workload was not associated with trainer prizemoney when other factors were taken into account, but more frequent rest breaks were associated with greater prizemoney per start earnt in the previous season. Intended trainer programs with moderate galloping distances as horses gain fitness for racing (i.e., not too high or too low compared to their peers), and moderate time between race starts were associated with better rates of wins and places. Workload associations with injury risk warrant further investigation, but these finding suggest that there is considerable scope for future modification of training workloads without negatively impacting trainer success rates and prizemoney earnings. Understanding the relationship between the training practices of Thoroughbred racehorses and race performance is important to ensure advice given to trainers for injury prevention or management is practical and consistent. We assessed associations between intended volume and speed of gallop training (i.e., typical workloads for horses free of injury or other performance limiting conditions) and rest practices on official trainer career and previous season success rates (rate of wins and places, prizemoney per start). Sixty-six Australian Thoroughbred trainers were surveyed. Multivariable negative binomial regression models were employed for the outcomes career and previous season wins and places, and linear regression models for prizemoney per start. Intended training workload was not associated with prizemoney. Pre-trial total galloping distances (>= 13.3 m/s) between 7500 m and 15,000 m were associated with a higher rate of career wins, and previous season wins and places per start (p < 0.05). Slow-speed (13.3-14.3 m/s) galloping distance to trial between 5000 m to 12,500 m was associated with higher rate of career placings per start, with reduced performance over 12,500 m (p = 0.003). Greater time between race starts was associated with a greater rate of previous season wins and prizemoney per start until three weeks between starts, with decline in performance thereafter (p < 0.05). Greater frequency of rest breaks was associated with greater prizemoney per start earnt in the previous season (p <= 0.01). These results suggest that modifications to training programs aimed at injury prevention, such as avoiding long galloping distances, should not adversely affect trainer success.