Blood lactate levels during exercise in athletic horses

Blood lactate concentrations are regularly used to assess the level of fitness in the athletic horse. The aim of this study was to compare the blood lactate concentrations during exercise of varying duration and intensity in horses. We used 145 horses of mixed gender, age, and breed. All the subjects were clinically healthy. They were divided into six groups based on the activities they were required to perform: jumpers, gallopers, trotters, trekking, treadmill, and swimming horses. A two-way ANOVA of blood lactate concentrations showed a statistically significant difference between gallopers and jumpers at rest. Immediately after exercise, trotters differed significantly from gallopers, trekking and jumpers, whereas 30 min after exercise, trotters differed only from gallopers and trekking horses. No significance was found for other groups. ANOVA showed a significant effect of time for jumpers and gallopers. Overall, trotters exhibited the lowest accumulation of lactate after exercise. We hypothesize that the lower velocity of trotting and the relative fast consumption of lactate in a fit horse are responsible for the difference between trotters and the other groups. The results obtained allow a scientific evaluation of the athletic potential of an individual horse and constitute an easy way to predict the horse's long-term performance.