EFFECTS OF TRAINING ON BLOOD LACTATE RUNNING SPEED RELATIONSHIP IN THOROUGHBRED RACEHORSES

In this study the effects of training history on the results of a stan dardized two-speed test in competing Thoroughbreds were investigated d uring a racing season. For nine Thoroughbreds, 1,755 training days wer e recorded. Within the observation period each horse completed a two-s peed field test at intervals of 6-8 wk to determine its running veloci ty (v) eliciting blood lactate concentrations of 4 (v(4)) and 12 mmol/ l (v(12)). Horses performed 29 two-speed tests. Changes of v(4) and v( 12) in a horse between two consecutive tests were used to assess effec ts of training history variables calculated for the period between two consecutive tests. The percentage of days with gallop workouts betwee n two consecutive tests showed a significant correlation with changes in v(4) (r = 0.71, P < 0.01) and v(12) (r = 0.56, P < 0.05). The numbe r of gallop workouts (r = 0.60, P < 0.05) and the total time of traini ng (r = 0.58, P < 0.05) correlated with the change of v(4). Furthermor e the percentage of days without training was negatively correlated to changes of v(4) (r = -0.75, P < 0.01) and v(12) (r = -0.56, P < 0.05) . Therefore the actual training caused changes in the blood lactate-ru nning speed relationship despite its relatively low volume, intensity, and frequency. Future studies have to evaluate how the training varia bles can be changed to improve the training effects on the blood lacta te-running speed relationship of competing Thoroughbreds.