Comparison of physiological demands in Warmblood show jumping horses over a standardized 1.10 m jumping course versus a standardized exercise test on a track

Proposed Protocol for Field Testing of Endurance Fitness of Young Labrador Retrievers

The number of dogs and, with it, dog sports are growing in popularity, and the training of dogs begins at an early age. Although fitness testing is an imperative part of purposeful training and sports, to our knowledge, no objective field tests are available for measuring young dogs' endurance fitness. The aim of this study is to describe a simple, easy-to-repeat, and inexpensive way to test training intervention effects on endurance fitness in young Labrador Retrievers. Healthy client-owned 16-week-old Labrador Retrievers will be recruited and divided into test and control groups. The test group will have an eight-week training program followed by a four-week detraining period, while the control group will live a normal puppy life. All dogs will be tested for endurance fitness four times at four-week intervals: at baseline, one month later, two months later at the end of the training period, and one month after ending the training program. Each of the four testing sessions will be identical and will consist of four measurements of heart rate (HR) and blood lactate (BL): at baseline, after trotting 1000 m, after sprinting 200 m, and at recovery 5-8 min after the sprint. The training-induced changes in endurance fitness are evaluated by changes in HR and heart rate recovery times (HRR), BL, and running times.

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

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.

Monitoring Performance in Show Jumping Horses: Validity of Non-specific and Discipline-specific Field Exercise Tests for a Practicable Assessment of Aerobic Performance

Show jumping is a highly specialized equestrian discipline that requires technical skill but also power and fitness. Monitoring the horses’ aerobic performance is therefore essential in order to verify whether the training has induced the desired cardiovascular and muscular adaptations. This study therefore aimed at evaluating the validity of non-specific and discipline-specific field exercise tests for objective evaluation of aerobic performance in show jumpers. For this purpose, data obtained from horses competing at Junior and Young Rider level during show jumping competitions as well as field exercise tests were retrospectively analyzed. The effect of the level of difficulty, the horses’ age, the penalty score and the horses’ previous level of performance on blood lactate concentrations after show jumping competitions (100 observations in 49 horses) was evaluated by linear mixed effects models (horse as random effect). Estimated marginal means significantly increased from 140 (4.1 mmol/L) to 150 cm (5.2 mmol/L) classes (P = 0.02). Furthermore, post-exercise lactate values significantly increased with the horses’ age (P = 0.001). Another group of 12 horses performed a standardized incremental field exercise test on a track (SET_track), a standardized show jumping course (SET_course) and a standardized grid exercise (SET_grid) each on three consecutive days. Indices of aerobic performance, derived from the SET_track [velocity at a heart rate of 140 bpm (V₁₄₀) and at a lactate concentration of 2 mmol/L (V_La2)] were highly correlated with heart rate (V₁₄₀: r = −0.75, P = 0.005; V_La2: r =−0.66, P = 0.02) and lactate (V₁₄₀: r = −0.73, P = 0.02; V_La2: r = −0.72, P = 0.02) in response to SET_course as well as heart rate during SET_grid (V₁₄₀: r = −0.73, P = 0.02; V_La2: r = −0.76, P = 0.01). Subjective rating of muscular fatigue was significantly correlated to the mean heart rate during SET_course (r = −0.64, P = 0.05) and SET_grid (r = −0.74, P = 0.02) but not to the aerobic indices calculated from SET_track. Besides non-specific incremental field tests, performance monitoring in show jumpers should therefore also include discipline-specific tests that more closely reflect the internal load induced by show jumping competitions.

Cost of transport, but not gluteus medius and red blood cells monocarboxylate-transporters density differentiated Brazilian Sport Horses at two performance levels

Cost of transport (COT) and monocarboxylate transporters (MCTs) could affect the ability to perform fast actions during a jumping discipline. This study aimed to compare the COT and evaluate the MCT1, MCT4, and their auxiliary protein CD147 content in the gluteus medius and RBCs of Brazilian sport horses (BH), a breed developed for jumping competitions, with low-level (LL) or intermediate-level (IL) jumping capacities. The physiological difference between the horses was assessed by an incremental jump test (IJT), in which the cost of lactate (COT_LAC) and heart rate (COT_HR) of running were determined for each animal by the ratio between each variable and the running speed. Western blotting was performed on muscle and RBC membranes to quantify MCT1, MCT4, and CD147. IL showed lower COT_LAC and COT_HR than LL at all jumping heights. The amount of MCT1, MCT4, and CD147 found in muscle and RBCs were not dependent on performance level. Muscle MCT4 and MCT1 were correlated positively with CD147. We conclude that the relatively small differences between performances did not relevantly influence MCT expression in BH. While MCT analyses are inaccessible for most trainers and veterinarians, the cost of transport measurements is a feasible and sensitive tool to distinguish intermediate and low-level jumping horses.