Modelling Speed and Inter-Race Intervals as a Proxy for Glycogen Restoration in Racing Greyhounds

Abstract The recovery of Greyhounds post-race has important welfare implications, primarily to avoid over-running and prevent Greyhounds with subclinical injuries from racing. Both situations could reasonably be expected to reduce performance, which may be identified by comparing the successive race performances of individual Greyhounds. The focus in this analysis was on reportedly sound Greyhounds and thus the hypothesis was that changes in performance would be due to changes in muscle glycogen stores, which may not have had time to be restored after the previous race. In order to determine whether changes in inter-race intervals affected performance, particularly where the inter-race interval was less than four days, a one-year dataset of raceform was analysed. The dataset contained 153,728 races of 9,190 reportedly sound GBGB-licenced Greyhounds and was analysed using R and MLwiN to generate a multilevel model. The results showed an undetermined effect on performance when there was only one day between races, due to lack of records in this part of the dataset, but showed unchanging performance when there were two or more days between races. As such the implication is that racing Greyhounds have fully recovered their glycogen stores by two days after a race. Performance depression after this time might suggest a subclinical injury. Expanded datasets are required to determine the effect of a one-day gap between races.