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Summary The purpose of this study was to investigate the kinetics of blood lactate concentration in 5 saddle horses during an incremental test on an inclined treadmill (3%). In order to mimic field conditions, the exercise test consisted of five 3 min bouts at increasing speeds (7.5, 8.3, 9.2 and 10 m/s); each bout being followed by 1 min rest. Blood samples were taken prior to each step, every minute during each step and every 30 s during each rest period. At low intensities of exercise, stability of blood lactate concentration was sometimes observed during the first minutes of the bout, followed by an increase in the second part. At higher intensities, blood lactate concentration rose more quickly and no stability was observed. Lactate concentration in the blood sample taken at t3′30 during the rest period, often reached a higher value than in the preceeding bout. The VLa4 calculated from blood lactate concentrations obtained at t3′ and t3′30 were not significantly different (P>0.05); mean ± s.d. 9.8 ± 0.7 and 9.8 ± 0.6 m/s, respectively. By using the blood lactate concentrations obtained at t4', the VLa4 appeared higher (mean ± s.d. 10.1 ±0.7 m/s).

Summary The purpose of this study was to demonstrate the relationships between jumping technique and dorsoventral acceleration measured at the sternum. Eight saddle horses of various jumping abilities competed on a selective experimental show jumping course including 14 obstacles. An accelerometric belt fastened onto the thorax continuously measured the dorsoventral acceleration during the course. At each jump, 11 locomotor parameters (acceleration peaks, durations and stride frequency) were obtained from the dorsoventral acceleration-time curves. The type of obstacle significantly influenced the hindlimb acceleration peak at take-off and the landing acceleration peak (P

Summary The aim of this study was to give riding teachers, physiotherapists and research workers a better understanding of the three-dimensional movement of the horse's saddle. The gaits of 7 horses were recorded on the treadmill by an accelerometric crown fixed to the front of a saddle. After a Fourier analysis of the signal, noise was eliminated; after a double integration data were obtained describing the crown's movement, assuming that after each stride the saddle returns to the original place. The movement was visualised in two and three dimensions. The walk showed more twisting motions, whereas the trot had more rolling, longitudinal and lateral movement. The canter showed the highest amplitude of motion, with a strong pitching rotation but little twisting. The pitching movement was the most important type of rotation for the three gaits. The speed at the canter did not influence the shape of the movement patterns.

Summary The purpose of this study was to compare the physiological responses of horses performing the same standardized exercise test, first in field conditions with a rider, and then on an inclined treadmill set at a 3.5% slope. Five saddle horses trained for three-day-event competition performed an exercise test consisting of five 3 min steps of increasing speeds (1.6, 4.2, 7.5, 8.3, 9.2 and 10 m/s). Following each step, blood samples were taken by jugular venipuncture during a 1 min rest period to determine blood lactate concentration (La). During the incremental test, the heart rate was recorded and the data averaged for each step. The exercise tests were carried out first on the fiat turf track and then one week later on the treadmill. No significant difference appeared between the mean heart rates (158.4 vs 158.5 beat/min; 171.0vs 167.8; 180.3 vs 178.9; 192.0 vs 190.2) and the blood lactate concentrations (1.03 vs 1.22 mmol/l; 1.73 vs 1.70; 2.99 vs 3.12; 5.38 vs 4.98) obtained at 7.5, 8.3, 9.2 and 10 m/s in overground and treadmill conditions, respectively. The velocity-dependent changes in the heart rate and blood lactate concentration were similar and the exercise parameters (V170, V200, VLa 3 and VLa4) did not differ significantly between the two exercise test conditions. It was concluded that a slope of 3.5% could simulate the workload of an incremental test performed by saddle horses running on a track with a rider.

Resume Le suivi de l'entrainement de l'athlete humain dans les disciplines de fond et de demi-fond fait appel a des tests d'effort de laboratoire et de terrain; les resultats de ces tests viennent aider l'athlete dans la conduite de son entrainement. A partir de nombreux points communs entre la physiologie a l'effort de l'homme et celle du cheval, il a ete possible de mettre au point un test d'effort standardise de terrain adapte au cheval de sport. Le but de ce test est de determiner la zone transitionnelle aerobie/anaerobie delimitee par les seuils de meme nom habituellement definie par les lactatemies de 2 et 4 mmol/l. A ces valeurs, sont rapportees les frequences cardiaques (FC); et les vitesses (V) correspondantes; cela definit les parametres FC2, V2, FC4, V4. Ces parametres guideront l'entraineur pour la preparation physique de l'athlete cheval.

The purpose of this study was to define the most suitable treadmill slope for reproducing the same heart rate response as in horses being ridden on a track. Seven French saddle horses were exercised first on a level turf track and then on a treadmill. On the track the exercise test consisted of four periods of three minutes of increasing speeds at the trot and the gallop (96 to 600 m/minute). The treadmill exercise tests consisted of seven steps of increasing slope (0 to 9.6 per cent) at the trot (252 m/minute), followed, after an active recovery period at the walk with a 0 per cent slope, by five steps of increasing slope for two minutes each (0 to 6.3 per cent), at the gallop at 493 m/minute. The mean heart rate at each step of the exercise tests was measured with a heart rate recorder. On the exercise track there was a strong linear relationship (R = 0.89, P0.01) between heart rate and speed. The heart rate response of the horses exercised at different speeds and slopes on the treadmill was best fitted (R = 0.96, P0.01) by a multilinear model. The optimal treadmill slope was determined by equalizing the equations derived from the two tests: s = -0.001 V + 3.658. It was concluded that the optimal treadmill slope ranged between 3.0 and 3.7 per cent. In order to verify this result, a comparison was made between the heart rate response of the horses during the same incremental exercise test performed on the track and on the treadmill with a 3.5 per cent slope.(ABSTRACT TRUNCATED AT 250 WORDS)

Summary Thirty horses were filmed with a panning camera operating at 50 frames/s as they jumped over a 1.20 times 1.20 m fence. The markers of 9 joints on the horse and 7 joints on the rider were tracked in 2D with the TrackEye system. The centre of gravity and moment of inertia of each segment were calculated using a geometric algorithm and a cylindric model, respectively. The kinetic moment of each part of the horse was calculated after filtering, and resampling of data. This method showed the relative contribution of each body segment to the body overall rotation during the take-off, jump and landing phases. It was found that the trunk, hindlimbs and head-neck had the greatest influence. The coordination between the motion of the body segments allowed the horse to control its angular speed of rotation over the fence. This remained nearly constant during the airborne phase (120 ± 5°/s). During the airborne phase, the kinetic moment was constant because its value was equal to the moment of the external forces (722 ± 125 kg.m2/s).

The purpose of this study was to compare the velocity-dependent changes in stride length and stride frequency of horses performing the same incremental exercise test first on a track with a rider and then on a treadmill with a 0 and 3.5% slope successively. Seven French saddle horses undertook the exercise test which consisted of 5 stages of increasing speed for 3 min each with 1 min rest between each stage (1.6, 4.2, 8.3, 9.2 and 10 m/s). The horses were recorded by use of a video camera, and the tapes were analysed with regard to gait parameters. At 1.6, 8.3, 9.2 and 10 m/s, stride frequencies were significantly (p < 0.01) greater on the track than on the treadmill. At the walk, stride length was significantly (p < 0.01) shorter on the track than on the treadmill. There were strong linear relationships between stride length and speed in all experimental conditions (R2 > 0.96). The comparison of the regression coefficients revealed significant differences (p < 0.01) between track and treadmill locomotion; stride length was longer on both the horizontal and inclined treadmill than on the track. The incline of the treadmill did not significantly (p > 0.01) influence stride parameters.

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Resume Le suivi de l'entrainement est realise par la lecture de la frequence cardiaque (FC) et le dosage de la lactatemie ([La]); ces moyens permettent de faire travailler un cheval a la vitesse estimee de son seuil anaerobie (V4) et d'assurer une reelle progression de sa vitesse de competition. Les parametres physiologiques (FC) et (La) sont determines pour chaque cycle d'entrainement. Toutes evolutions de ceux-ci guident l'entraineur pour adapter la charge de travail au niveau actuel de condition du cheval.

Kinetics of blood lactate was followed in five three-day-event horses. Two tests were made at constant velocity during 8 min on a treadmill, first at VLa 3 then at VLa 4 . These velocities were determined for each horse by an exercise step test in a previous study. In constant velocity tests, a rapid rise in blood lactate was observed up until the third minute of exercise. For the VLaa test, a steady state was achieved between the 4th and the 8th rain. Horses completed the test with a blood lactate concentration lower than 3 mmol/1. The anaerobic threshold could be estimated at 2.25 ± 0.40 mmol/1. For the VLa4 test blood lactate rose linearly from the let to the 8th rain and no steady state was achieved. The mean rate of accumulation was 0.25 mmol/1/min. For three-day-event horses, VLa 4 did not represent the individual anaerobic threshold for an 8 min constant exercise.