Reproducibility of a standardised exercise test for Standardbred trotters under field conditions

Summary The reproducibility of a standardised exercise test was evaluated in 2 conditions with 2 groups of Standardbred horses: 1) the first condition was a test and a re-test performed with a 1 week interval by 11 trotters on their usual training track (2) the second condition was a test and a re-test performed with another group of 8 horses on 2 different tracks with a 9 day interval, in order to assess the influence of changing the place of the test. The test was composed of 3 steps, conducted at an increasing speed. The duration of each step was 3 min with a 1 min rest between 2 steps at a walking pace. The speed level used for each step depended on the age and fitness of the horses. Mathematic treatment of the collected data, speed, heart rate and venous blood lactate measured after each step, allowed the estimation of 5 fitness parameters: V200, V4, V2, HR2 and HR4. The Spearman rank correlation coefficients calculated for these indicators between the 2 tests measured during the experiment (1) and the experiment (2) were higher than 0.79 (P < 0.05) for V200, V4, V2 and HR2. The standardised exercise test proposed in the present work, was demonstrated to be reliable in field conditions for Standardbred horses.