Longitudinal Training and Workload Assessment in Young Friesian Stallions in Relation to Fitness: Part 1

SIMPLE SUMMARY: Young Friesian stallions have to complete a 10-week training program (70-day test) to become studbook approved breeding stallions. The effect of this training program, consisting of dressage and driving training, on fitness progress was evaluated in this study. Data were collected in the 9 weeks preceding the training program, and during the 70-day test. Duration and time spent at walk, trot and canter for all training sessions were measured in the participating 16 stallions. Each stallion had to perform three ridden standardized exercise tests in week 1, 6 and 10 of the 70-day test, during which heart rate and plasma lactate concentration were measured. Horses were trained for a longer duration in the 70-day test compared to the preceding weeks. Heart rate and plasma lactate concentration of the horses increased in the second and third exercise test compared to the first exercise test, indicating that the stallions were more fatigued during the second and third exercise tests. These results indicate that the fitness of Friesian stallions decreased during 70-day test, suggesting overtraining. The 10-week training program needs to be adjusted to optimize training effects and welfare of the horses. ABSTRACT: Friesian stallions have to complete a 10-week studbook approval test (70-day test) consisting of dressage and driving training for acceptance as a breeding stallion. Training response of the horses to this approval program was evaluated. External workload (EW) of 16 stallions (3.2 ± 0.4 years old) was registered during the 9 weeks preceding the 70-day test (preparation period) and during 70-day test. Ridden indoor standardized exercise tests (SET), measuring heart rate (HR) and plasma lactate concentration (LA) at walk, trot and canter, were performed in week 1 (SET-I), 6 (SET-II) and 10 (SET-III) of the 70-day test. Linear mixed effect models were used to analyze HR and LA related to SETs and EW related to the phase of the study, using Akaike’s information criterion for model reduction. EW was higher in the 70-day test compared to the preparation period, with longer duration of training sessions. Compared to SET-I, horses showed increased HR and LA after canter in SET-II and SET-III, indicating that they were more fatigued. The fact that the fitness of these Friesian stallions decreased during the 70-day test suggests overtraining. To optimize training effects and welfare of these horses, the workload of the training program needs to be adjusted.