The impact of the mandatory rest period in Federation Equestre Internationale endurance events

Background Endurance riding competitions are increasingly popular, with a corresponding awareness of the frequency of Failure to Qualify (FTQ) due to lameness or metabolic problems. Federation Equestre Internationale (FEI) rules require a minimum number of days between competitions, known as a mandatory rest period (MRP). Objectives To analyse the impact on FTQ outcomes of MRPs which applied between January 2014 and December 2016, and model potential changes to MRPs to establish which rule change could lead to the largest further reduction in the number of FTQ outcomes. Study design Retrospective cohort study and predictive model using a subset of data collected by the FEI of every horse start worldwide in Concours de Raid d'Endurance Internationale (CEI) competitions between 2010 and 2017. Methods Descriptive statistics followed by predictive/retrospective modelling of potential scenarios. Scenarios involved extended MRP for all horses and/or for only the fastest ridden horses. Results There were clear direct benefits demonstrated from the introduction of MRPs. Among directly affected horses, current MRPs could have prevented 2.3% of FTQ outcomes. Further benefits could be gained by extending MRPs. The 'best-value' impact could be found in a 1-week extension for all horses plus a 1-week extension for the fastest ridden horses - which could result in a reduction of up to 11.5% of FTQ outcomes among directly affected horses. Main limitations The data set covers all FEI competitions but no National Federation events. The data set is geographically comprehensive but it does not include every competition started by every individual horse. Training data for each horse were not available. Conclusions Mandatory rest periods for horses between endurance competitions have had the intended impact of reducing numbers of FTQ outcomes in CEI events. Further benefits could be gained by extending rest periods for all horses and/or for horses ridden at the highest average speeds.