Exercise physiology in horses involves the study of the physiological responses and adaptations of horses to physical activity. This field examines how exercise impacts various systems in the equine body, including the cardiovascular, respiratory, muscular, and metabolic systems. Researchers focus on understanding how these systems interact during different types and intensities of exercise, and how they contribute to performance and recovery. Key areas of interest include the assessment of aerobic and anaerobic capacity, muscle fiber composition, energy metabolism, and thermoregulation. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms of exercise physiology in horses, with an emphasis on performance optimization, training regimens, and the prevention of exercise-related disorders.
Goetz TE, Manohar M.Pressures in the right side of the heart and esophagus (pleural) have not been determined in the exercising equine subjects. In the present study, 8 healthy ponies were examined to determine the changes in these variables caused by 2 degrees of exercise done on a treadmill (heart rate:183 +/- 5 beats/min [trot] and 220 +/- 6 beats/min [canter]). Measurements were also made during both degrees of exertion 10 minutes and 120 minutes after furosemide (1.0 mg/kg) administration. It was observed that both gaits resulted in significant increases in pulmonary artery, right ventricular, and right atri...
Tschudi P.The use of the ECG to separate the different phases of the heart cycle registering other physiological signals, to evaluate the fitness and state of training of a horse and to detect a pregnancy of a mare is reported and illustrated in this text.
Kalinskiĭ MI, Kamenetskaia OV, Skorik LG, Tishchenko GN.The paper deals with possibility to regulate in a proper direction the acid-base state in race horse blood administering carbostimulin at rest and under physical exercises. The preparation is shown to favour an increase in alkaline blood reserves in race hours at rest and to prevent acidotic changes caused by physical exercises. The results obtained show a promising use of carbostimulin for the directed correction of the acid-base state of blood in race horses aimed at increasing the efficiency of the training process.
Hodgson DR, Rose RJ, Dimauro J, Allen JR.Biopsy samples were obtained from the middle gluteal muscle of 10 Thoroughbred horses undergoing a commercial race-training program. Samples were obtained before the program began and again after 6 and 12 weeks of training. All horses had raced at least once by the 12th week of training. Serial sections of muscle were examined histochemically for myosin adenosinetriphosphatase after either acid (pH 4.3 and 4.6) or alkaline (pH 10.3) preincubation, and then muscle fibers were identified as types I, IIA, IIB, or IIC. The oxidative capacity of individual fibers was assessed, using the reduced nic...
Derksen FJ, Stick JA, Scott EA, Robinson NE, Slocombe RF.The effect of left laryngeal hemiplegia on airway flow mechanics in 5 exercising horses was examined, and the efficacy of surgical repair by prosthetic laryngoplasty was evaluated. Measurements of the upper airway flow mechanics were made with horses on a treadmill (incline 6.38 degrees) while standing (period A); walking at 1.3 m/s (period B); trotting at 2.6 m/s (period C); trotting at 4.3 m/s (period D); and standing after exercise (period E). Experiments were done on healthy horses before any surgical manipulation (control), at 10 days after left recurrent laryngeal neurectomy, and at leas...
De Waal A, Littlejohn A, Potgieter GM, Van der Berg J, Minnaar PI, Smith A.An apparatus was designed to collect four consecutive blood samples from exercising horses. The collection of each sample was controlled by valves activated by radiotelemetry signals transmitted by an observer. Using the device, venous blood samples were collected from ten thoroughbred racehorses before, during and after a 400 m training gallop. Blood glucose increased markedly post-exercise. Both phosphorus and potassium concentrations increased during exercise, decreased post-exercise and recovered to pre-exercise levels within 120 minutes. The system was modified to collect anaerobic sample...
Elsner R.Examples of exercise performance and metabolic scope in non-human mammalian species are considered from the point of view of problems and questions which may provide insights into evolutionary processes influencing adaptations to muscular activity. Consideration of both aerobic and anaerobic performance is required. Some recent approaches, notably that concerned with the concept of symmorphosis, the integration of design for the accommodation of variations in activity, show promise of new ways for comparative investigations of the adjustments to exercise.
Dalin G, Jeffcott LB.Gait analysis can play an important role in exercise physiology, racetrack ergonomics, lameness prophylaxis, and assessment of performance potential in racehorses. This article concentrates on the methods used for gait analysis and considers some basic data on the different gaits of the horse.
Lovell DK.Through the study of equine exercise physiology, one can learn more about what happens to the body of the performance horse during all forms of exercise. Better understanding of skeletal, joint, tendon, and ligament adaptations to loading and stress may allow adjustments to be made in training techniques to reduce the incidence of injury. The information obtained from exercise research may also facilitate the investigation of questions such as the following: What makes one horse perform better than another? How can one bring out the optimal performance in each horse? How can one tell when a ho...
Bayly WM.A training program is designed with the aim of developing the specific physiologic capabilities required to perform a certain type of exercise. Such capabilities involve the psychologic familiarity with, and acceptance of, the required tasks, the development of the neuromuscular coordination to perform these tasks optimally, and the utilization of energy by the working muscles. This article presents some basic principles for the design of training programs and offers ideas on how these principles may be applied to the conditioning of horses.
Hodgson DR.Maintenance of muscular contraction during exercise requires large amounts of chemical energy. Although various sources of energy are available, adenosine triphosphate (ATP) is the universal intracellular vehicle of chemical energy within skeletal muscle. This article will focus on the various mechanisms of the production and breakdown of ATP.
Rose RJ, Allen JR.Hematology has been widely used in attempts to provide information about disease states, performance problems, and fitness in performance horses. However, owing to factors such as the temperament of the horse and time of collection and feeding, considerable variation in the hemograms can be found. This article reviews some of the hematologic responses to exercise and training.
Robinson NE.The primary function of the equine respiratory system is the exchange of oxygen and carbon dioxide at a rate that is matched to metabolism. Gas exchange requires ventilation, distribution of gas within the lung, perfusion of blood through pulmonary capillaries, matching of ventilation and blood flow, diffusion of gases between air and blood, and transport of gases to and from the muscles. In this article, the author reviews what is known about each of these processes in the resting and exercising horse.
Hodgson DR.This article provides an overview of the characteristics of skeletal muscle, with an emphasis on equine skeletal muscle. A discussion of many of the adaptive processes that can occur in this tissue in response to altered states of physical activity is also included.
Evans DL.The cardiovascular system provides the link between pulmonary ventilation and oxygen usage at the cellular level. During exercise, efficient delivery of oxygen to working skeletal and cardiac muscles is vital for maintenance of ATP production by aerobic mechanisms. The equine cardiovascular response to increased demand for oxygen delivery during exercise contributes largely to the over 35-fold increases in oxygen uptake that occur during submaximal exercise. Cardiac output during exercise increases greatly owing to the relatively high heart rates that are achieved during exercise. Heart rate i...
Essén-Gustavsson B, Lindholm A.Muscle biopsies were taken from the middle gluteus muscle of 36 Standardbred horses. Twelve of the horses were inactive, while 24 were actively trained and raced. Twelve of the trained horses were moderate performers, with a mean racing time of 1 min 21 secs per km (741 m/min) and the other 12 were excellent performers, with a mean racing time of 1 min 16 secs per km (789 m/min). The percentage and mean area of Type I fibres were similar in all three groups of horses. Marked differences were found among the subgroups of Type II fibres. The well-trained horses had a higher proportion of Type II...
Bove AA.Myocardial blood flow is the major determinant of oxygen delivery to the myocardium, since oxygen extraction by the myocardium is near maximum in the resting state. Regulation of flow during exercise depends on local metabolic factors and, to a small extent, on autonomic tone. Maximum flow of 5-6 times resting has been measured in reactive hyperemia experiments. In strenuous exercise, myocardial oxygen delivery appears to be adequate and flow reserve seems capable of handling the increased oxygen demand. No evidence of myocardial failure in normal hearts due to excess exercise has been present...
Cutmore CM, Snow DH, Newsholme EA.The effect of physical training on the in vitro activities of key enzymes that provide quantitative information on the maximum capacities of anaerobic and aerobic metabolism has been investigated in the gluteal muscle of the horse. Training had no effect on the activities of 6-phosphofructokinase or creatine kinase, suggesting that there was no effect on the capacity of anaerobic metabolism in this muscle. However, the activities of hexokinase and citrate synthase were increased, indicating that training increased the capacity of aerobic metabolism. For comparative purposes, muscle fibre compo...
Orton RK, Hume ID, Leng RA.Rates of growth were measured in two-year-old (Experiment 1) and nine-month-old (Experiment 2) horses fed high (12 or 14 per cent) or low (6 or 8 per cent) crude protein diets with one of two levels of exercise (0 or 12 km trotting per day at 12 km/h). In the non-exercised horses feed intakes and growth rates were greater on the high than on the low protein diets. Exercise increased feed intakes and growth rates of horses on the low but not the high protein diets, so that in the exercised groups there were no significant differences in feed intakes or growth rates between the horses on the two...
Physick-Sheard PW.The quality of the overall response to exercise in the horse is very similar to that seen in man and laboratory animals; differences are mainly quantitative and persist when relative body weight is taken into account. The apparently greater flow capacity of the equine muscle bed during maximal whole-body exercise implicates the extent of central circulatory adaptations as the limiting factor in performance but implies a role for increase in arteriolar capacitance/muscle capillarity as an appropriate response to intense endurance training. The blood oxygen-carrying capacity of the horse is ofte...
Ratzlaff MH, Shindell RM, DeBowes RM.Blood pressures from the catheterized lateral digital vein of the fore-limbs of 6 clinically normal horses were measured at rest, at the walk, and at the trot. Digital venous pressures were compared with the phases of the stride and weight-bearing forces, using electrogoniometry and a force platform. Rapid increases in digital venous pressures to maximal values were observed immediately before maximal forces during the support period of the stride. At the trot, increases in peak vertical forces were paralleled by increases in peak digital venous pressures. Seemingly, the hydrodynamics of the d...
Hodgson DR, Rose RJ, DiMauro J, Allen JR.The effects of training on skeletal muscle composition were studied in four Standardbred geldings given a seven week submaximal treadmill training programme. Before the start of training, muscle biopsies were collected from the left middle gluteal muscle for the determination of muscle fibre types, oxidative capacity and capillary numbers using histochemical techniques. The concentrations of citrate synthase, 3-hydroxyacyl-CoA dehydrogenase (HAD), lactate dehydrogenase and total muscle glycogen were measured using fluorometric methods. Muscle biopsy samples were repeated after one, three, five...
Parks CM, Manohar M.In recent years, increasing attention has been focused on the physiological responses of the horse to maximal exercise. Cardiovascular response in near maximally exercised galloping ponies (heart rate 225 +/- 7 beats/min; whole body oxygen consumption 122 +/- 12 ml/min/kg) comprised a marked increase in blood flow to the cerebellum, myocardium, diaphragm and the working muscles, while renal blood flow decreased precipitously. Cerebral and brainstem perfusion did not vary from resting values. Transmural homogeneity of myocardial blood flow persisted during near maximal exercise. It was reported...
Kaminski RP, Forster HV, Bisgard GE, Pan LG, Dorsey SM, Barber BJ.The purpose of this study was to determine if the changes in O2 consumption (VO2) during CO2 inhalation could in part be due to stimulation of thermogenesis for homeothermy. Twelve ponies were exposed for 30-min periods to inspired CO2 (PIco2) levels of less than 0.7, 14, 28, and 42 Torr during the winter at 5 (neutral) and 23 degrees C ambient temperatures (TA) and during the summer at 21 (neutral TA), 30, and 12 degrees C. Elevating TA in both seasons resulted in an increased pulmonary ventilation (VE) and breathing frequency (f) (P less than 0.01) but no significant increase in VO2 (P great...
Snow DH, Harris RC, Gash SP.Four thoroughbred horses performed 4 gallops (G1-G4) with intervals of 5 min. With one exception, gallops were sustained at maximal speed over 620 m. Muscle biopsy samples of the middle gluteal and brachiocephalicus were taken before, during, and after exercise and assayed for ATP and intermediary metabolites. The results showed a major involvement of the brachiocephalicus, in addition to the middle gluteal, during galloping. In three horses, who were clearly fatigued, muscle ATP decreased by up to 50% by the end of G4. This was matched by an equal rise in inosine 5'-monophosphate. Pronounced ...
Hodgson DR, Rose RJ, Allen JR, Dimauro J.Muscle biopsy samples were collected from the left middle gluteal muscle of the horses participating in day 2 (speed and endurance test) of a three day event. Six Thoroughbred horses were biopsied the day before and within 30 minutes of completion of the speed and endurance test. Serial muscle sections were reacted histochemically for myosin adenosine triphosphatase activity after acid pre-incubation to demonstrate Type I, IIA and IIB fibers and the glycogen content in the individual fibers was assessed using the periodic acid Schiff (PAS) reaction. Total glycogen in muscle was measured fluoro...
Manohar M, Goetz TE, Hassan AS.Work is required to establish the role of endogenous nitric oxide (NO) in metabolism of resting and exercising horses. Objective: To examine the effects of NO synthase inhibition on O2 extraction and anaerobic metabolism at rest, and during submaximal and maximal exertion. Methods: Placebo and NO synthase inhibition (with Nomega-nitro-L-arginine methyl ester [L-NAME] administered at 20 mg/kg bwt i.v.) studies were performed in random order, 7 days apart on 7 healthy, exercise-trained Thoroughbred horses at rest and during incremental exercise leading to 120 sec of maximal exertion at 14 m/sec ...
Busse NI, Gonzalez ML, Wagner AL, Johnson SE.Optimal athletic performance requires meeting the energetic demands of the muscle fibers, which are a function of myosin ATPase enzymatic activity. Skeletal muscle with a predominant oxidative metabolism underlies equine athletic success. Sodium butyrate, a short-chain fatty acid, can affect muscle fiber composition in pigs. To determine if a similar scenario exists in horses, 12 adult Thoroughbred geldings (7.4 ± 0.6 yr of age; mean ± SEM) were fed 16 g of calcium butyrate (CB) or an equivalent amount of carrier (CON) daily for 30 d in a crossover design. Middle gluteal muscle biopsies were...
Hallebeek JM, van Doorn DA, Beynen AC.In horses that exercise intensively (for example, event horses in training) the intake and energy requirements were compared on the basis of a diet record and estimates of energy required for exercise. Daily net energy intake over a 7 days period was on average 30% (n = 15) higher than the net energy requirement. Since the horses had a constant body weight, and thus were in energy balance, the energy intake was overestimated and/or the energy requirement was underestimated. The intake of digestible protein was 92% higher than the protein requirement. This study illustrates the problems concern...
Greene HM, Hurson MJ, Wickler SJ.Despite the common use of equids as visitors to high altitude mountainous environments, there are a paucity of carefully orchestrated scientific approaches. Further, again as a function of a common perceived advantage of mules over horses in these similar environments there are needs for controlled comparisons between these 2 equids. Objective: To measure haematological and respiratory function in horses and mules at low altitude (225 m), at rest and post exercise. In addition the rate and magnitude of these changes were followed over a 13 day period at high altitude (3800 m) to contrast accli...
Rolling is a natural behavior of equids that is beneficial to their well-being. However, more intensive domestic environments offer fewer opportunities for animals to roll, neglecting its importance. We believe that the inclusion of recreational areas for animals, containing substrates and conditions that encourage the occurrence of natural behaviors, is essential to promote their well-being. Therefore, we evaluated the preference of horses (; n = 8) and mules (E. asinus x E. caballus; n = 8) for different rolling substrates (sand, grass, manure), and the influence of this behavior on thermo...
de Graaf-Roelfsema E, Keizer HA, van Breda E, Wijnberg ID, van der Kolk JH.To determine the influence of intensified training and subsequent reduced training on glucose metabolism rate and peripheral insulin sensitivity in horses and identify potential markers indicative of early overtraining. Methods: 12 Standardbred geldings. Methods: Horses underwent 4 phases of treadmill-based training. In phase 1, horses were habituated to the treadmill. In phase 2, endurance training was alternated with high-intensity exercise training. In phase 3, horses were divided into control and intensified training groups. In the intensified training group, training intensity, duration, ...
Mitten LA, Hinchcliff KW, Pate JL.The effect of inhibition of cyclooxygenase activity on the hemodynamic response to exertion was examined in 6 horses. Rates of O2 consumption and CO2 production and carotid, pulmonary arterial, and right atrial pressures were measured while the horses performed a standardized exercise test on a treadmill after treatment with phenylbutazone or a placebo. Phenylbutazone (8.8 mg/kg p.o. for 2 days and 4.4 mg/kg i.v. 60 min before exertion) abolished the exertion-induced increases in plasma 6-ketoprostaglandin F1 alpha and thromboxane B2 concentrations, confirming inhibition of cyclooxygenase acti...
Manohar M, Duren SE, Sikkes B, Day J, Baker JP.Distribution of blood flow among various respiratory muscles was examined in 8 healthy ponies during submaximal exercise lasting 30 minutes, using radionuclide labeled 15-microns diameter microspheres injected into the left ventricle. From the resting values (40 +/- 2 beats/min; 37.3 +/- 0.2 C), heart rate and pulmonary arterial blood temperature increased significantly at 5 (152 +/- 8 beats/min; 38.6 +/- 0.2 C), 15 (169 +/- 6 beats/min; 39.8 +/- 0.2 C), and 26 (186 +/- 8 beats/min; 40.8 +/- 0.2 C) minutes of exertion, and the ponies sweated profusely. Mean aortic pressure also increased progr...
Kozlov SA.The results of applying N. N. Sirotinin's concept of the use of hypoxic adaptation to enhance working capacity are given. There is evidence for the efficiency of adaptation of trotters to two hypoxias: to hypoxic hypoxia (in the midmountains) and to exercise hypoxia (during interval training under the conditions of Moscow) for increasing their performance. These studies demonstrated that in the midmountains, the trotters had more infrequent respiration, increased respiratory and minute respiratory volumes which were more obvious by the end of a monthly mountain stay. The monthly training of tr...
Kovár J.The possibility of using the test for pulse-rate response to gradated load in the evaluation of the endurance component of horse performance (in other words, response to the degree of horse adaptation to load) is discussed in detail. A mathematic-statistical analysis of regression coefficients is performed in the equations of the dependence of pulse rate on speed obtained in 278 three years old horses in the period following the termination of the basic training (145 Bohemian Warm-Blooded horses, 115 Kladrub Black horses and 18 English Half-Breds). A ten-score scale is calculated on the basis ...
Pringle J, MacMillan K, Briand H, Stämpfli H.The heart rate changes during routine training in a group of 8 actively racing Standardbreds were used to simulate the training work on a treadmill (ST) and indices of exercise compared to maximal effort (MAX) on the treadmill. The following parameters were recorded during treadmill work: heart rate, velocity, O2 consumption, respiratory and stride frequency, and stride length. Blood lactate concentrations were measured before and after each work test. Heart rate during simulated training was mean +/- s.d. 87.8 +/- 5.5% heart rate in MAX, one of the 8 horses working 0.05), being higher during...
Larsdotter S, Holm L, Dahlborn K, Jansson A, Josefsson M, Ridderstråle Y.Sweat gland morphology and carbonic anhydrase (CA) distribution was studied after exercise in trained and untrained horses using a histochemical technique and light microscopic image analysis. Three trained and 3 untrained Standardbred trotters performed an exercise test (20 min trot at 6 m/s with 5 min walk at 1.8 m/s in the beginning and end) on a high-speed treadmill at 35 degrees C. Skin biopsies were taken before exercise and after trot. The fluid loss after exercise was 10, 12 and 12 g/kg bwt in the untrained horses and 4, 6 and 11 g/kg in the trained. Trained horses had a larger cell ar...
Muñoz A, Esgueva M, Gómez-Díez M, Serrano-Caballero JM, Castejón-Riber C, Serrano-Rodríguez JM.Changes in blood pressure (BP) during acute hypertension in response to angiotensin-converting enzyme inhibitors (ACEIs) have not been investigated in normotensive horses. In this study, six healthy horses were subjected to five trials, consisting in a treadmill exercise workload of 8 m/s for 1 min, 2 h after oral administration (PO) of placebo (0 mg/kg), enalapril (2.0 mg/kg), quinapril (1.0 mg/kg), ramipril (0.2 mg/kg) or benazepril (0.5 mg/kg). Serum angiotensin converting enzyme (ACE) activity was measured and systolic (SBP) and diastolic (DBP) blood pressures were recorded...
Bertuglia A, Pagliara E, Manca F, Pozzolo P, Mannelli A.The objective of this study was to report recovery time, retirement rate, racing performance, and presence of compensation pattern after musculoskeletal injuries (MSIs) in Standardbred racehorses (STBRs). This is a retrospective single open-cohort study, enrolling 356 STBRs in training in a single racetrack. Musculoskeletal injury was defined as any training-related injury after which the horse did not train for at least 15 days. The first and second MSIs encountered during the horse's racing career were considered. Medical records, training logbooks, and racing data were reviewed to determin...
Stampfli HR, Misiaszek S, Lumsden JH, Carlson GP, Heigenhauser GJ.The plasma proteins are a significant contributor to the total weak acid concentration as a net anionic charge. Due to potential species difference, species-specific values must be confirmed for the weak acid anionic concentrations of proteins (Atot) and the effective dissociation constant for plasma weak acids (Ka). We studied the net anion load Atot of equine plasma protein in 10 clinically healthy mature Standardbred horses. A multi-step titration procedure, using a tonometer covering a titration range of PCO2 from 25 to 145 mmHg at 37 degrees C, was applied on the plasma of these 10 horses...
Clark L, Bradley EJ, Mackechnie-Guire R, Taylor A, Ling J.Asymmetry of horses and humans is widely acknowledged, but the influence of one upon the other during horse riding is poorly understood. Riding simulators are popular for education of beginners and analysis of rider biomechanics. This study compares trunk kinematics and saddle forces of 10 experienced riders (ER) and 10 novice riders (NR) performing rising trot on a simulator. Markers were placed on the 4th lumbar (L4) and 7th cervical (C7) spinous processes, and both acromion processes. Displacements in three axes of motion were tracked using 10 high-speed video cameras sampling at 240 Hz. Di...
Johnson SE, Barshick MR, Gonzalez ML, Riley JW, Pelletier ME, Castanho BC, Ealy EN.Strenuous exercise can cause tissue damage, leading to an extended recovery period. To counteract delayed post-exercise recovery, a commercial product containing L-carnitine (AID) was tested in adult horses performing consecutive exercise tests to exhaustion. Fit Thoroughbreds were administered an oral bolus of placebo (CON) or AID prior to performing an exercise test to exhaustion (D1). The heart rate (HR) and fetlock kinematics were captured throughout the exercise test. Blood was collected before, 10 min and 1, 4 and 6 h relative to exercise for the quantification of cytokine (1, 8, 10, ) g...
Lindner A.The mean maximal lactate concentration of horses after exercise (Lamax) amounted to 4.5 +/- 2.2 mmol/l for gallop workouts of less than 11 m/s and more than 180 s (n = 35; category A), at more than 11 m/s and less than 180 s duration (n = 17; category B) to 16.3 +/- 4.8 mmol/l and at less than 11 m/s and less than 180 s duration (n = 10; category C) to 4.6 +/- 1.6 mmol/l. Lamax was always measured immediately after exercise following exercise of categories A and C. But for exercise bouts of category B Lamax was measured between the first and the tenth minute after exercise. Following exercise ...
Soroko M, Górniak W, Godlewska M, Howell K.The aim of this study was to evaluate the influence of training on body surface temperature over the joints in racehorses, measured by infrared thermography. The study involved monitoring of 14 Thoroughbred racehorses in 6 imaging sessions over a period of 3 months. Temperature measurements of the forelimb and hindlimb joints were made before and just after training. Joint temperature of limbs increased significantly after training. Environmental temperature had a statistically significant influence on surface temperature over the joints. The lowest surface temperatures were recorded over the ...
Fortier J, Deley G, Julliand V.This study aimed at quantifying energy expenditure during 4 specific training exercises, that is, promenade, jogging, parcours, and interval exercises, using field measurements of oxygen consumption and heart rate in trotters. Six animals performed 2 preliminary tests to determine their individual maximum velocity and to establish their individual oxygen consumption/heart rate relationship from an incremental test. Then, they undertook each of the 4 specific exercises separated by 1 wk to avoid fatigue. The intensity of the 4 exercises was expressed in percent of individual maximum velocity as...
McKeever KH, Malinowski K, Christensen RA, Hafs HD.The purpose of this experiment was to test the hypothesis that chronic (89 days) administration of recombinant equine somatotropin (eST) would increase aerobic capacity and improve exercise performance in old mares. Fifteen, healthy, unfit, aged (20-26 year old) mares were randomly assigned to a treatment (eST, 12.5 mg day-1 in 3 ml glycine/manitol buffer, s.c., n = 7) or control (vehicle, 3 ml day-1, s.c., n = 8) group. Aerobic capacity and exercise performance were measured using a standardized exercise test (SET) performed on a high speed treadmill. Tests were conducted before (-21 days), d...
Ehrlich PJ, Seeherman HJ, Morris E, Kolias C, Cook WR.The effect of left recurrent laryngeal neuropathy (LRLN) on the metabolic cost of locomotion (MCL) and peak aerobic power (VO2peak) was evaluated in four trained Thoroughbred racehorses. Oxygen consumption (VO2), carbon dioxide production (VCO2), venous lactate concentrations (LAC), and heart rate (HR) were measured during a treadmill exercise test (TET). Each horse performed the exercise test four times, alternating between normal upper airway function and reversibly induced LRLN. Subcutaneous infusion of 2% mepivicaine, a local anesthetic, into the region were the left recurrent laryngeal ne...
Danek J, Flosadóttir S.The purpose of this work was to assess the impact of a specific equestrian training, conducted in winter weather conditions, on the thermovision temperature distribution of a rider's body surface. The study included a riding pair with 12 years of experience (female rider, aged 25, sports active and 16-year-old horse, Trakehner breed). Methods: The study included the temperature distribution of selected parts of the rider's body (the area of the right and left shoulder blade, chest and lumbar section, and the region of the left and right cross) was carried out before and after recreational, jum...
Kallings P, Persson SG, Essén-Gustavsson B.Since nonsteroidal anti-inflammatory drugs, such as flunixin, on account of their anti-inflammatory and analgesic properties, are used in both racing and equestrian sport horses, the question has been raised as to whether these drugs affect the physiological responses to exercise and thus performance potential. Objective: The aims of this investigation were to study the effects of flunixin on cardiorespiratory, metabolic and locomotor parameters in horses during intense treadmill exercise. Methods: Six Standardbred trotters underwent an incremental treadmill exercise test to fatigue, without d...
Guhl A, Lindner A, von Wittke P.To examine the reproducibility of blood lactate-running speed curve parameters derived by a curve-fit equation and by linear interpolation from the results of 4-speed tests of sport horses under field conditions. Methods: Thoroughbreds completed 10 test pairs with 3 to 11 days between tests and retest. Methods: 7 Thoroughbreds. Methods: The 4-speed test consisted of 4 runs over a distance of 2,110 m. Exercise intensity was increased by 1 m/s for each run. Blood lactate concentration measured after each run was plotted against running speed to determine the blood lactate-running speed relation....
Kritchevsky J, Olave C, Tinkler S, Tropf M, Ivester K, Forsythe L, Couetil L.The use of thyroid supplement is pervasive in athletic horses although its effects on measures of performance are not known. Objective: One purpose of this study was to determine whether supra-physiologic doses of levothyroxine affect the velocities at which blood lactate was greater than 4 mmol/L (VLa4 ) and heart rate was over 150 (V150 ) and 200 (V200 ) beats per minute respectively. Additionally, a survey of post-race blood samples was also conducted to determine whether high thyroxine concentrations were common in racehorses. Methods: A randomised, crossover, trial was performed in six h...
Seeherman HJ.The use of motorized treadmills has made it possible to evaluate equine poor performance with sophisticated diagnostic techniques during peak exercise. Treadmill exercise tests currently being used for clinical evaluations include treadmill gait analysis, dynamic hoof balancing, endoscopic evaluation of upper airway function, and exercise performance profiling. Large motorized treadmills (1 to 1.5 m in width and 4 to 5 m in length) are best suited for clinical evaluations. Ideally, the treadmill should be installed in-ground using a pit. This type of installation results in the tread surface b...
Cornelisse CJ, Holcombe SJ, Derksen FJ, Berney C, Jackson CA.To determine the effect of a tongue-tie on upper airway mechanics in exercising horses. Methods: 5 Standardbreds. Methods: Peak inspiratory and expiratory tracheal and pharyngeal pressures and airflow were measured while horses exercised on a treadmill with and without a tongue-tie. Respiratory rate was also measured. Horses ran at speeds that corresponded to 50 (HR50), 75, 90 (HR90), and 100% of maximal heart rate. The tongue-tie was applied by pulling the tongue forward out of the mouth as far as possible and tying it at the level of the base of the frenulum to the mandible with an elastic g...
Cogger N, Perkins N, Hodgson DR, Reid SW, Evans DL.To describe the impact of age, sex, and musculoskeletal (MS) injury on three preparation-level measures of performance: (i) the duration of preparation, (ii) time from the beginning of the preparation until the first start in a race or barrier trial, and (iii) time from the first start until the end of the preparation. Methods: Daily training and injury data for 2- and 3-year old Thoroughbred racehorses were collected fortnightly from 14 trainers in NSW, Australia. Training data were aggregated into units referred to as 'preparations'. Univariate and multivariate analytical methods were used t...
Gerard MP, Hodgson DR, Lambeth RR, Ray SP, Rose RJ.The recent availability of recombinant equine somatotropin (eST) has led to concern about its use as an ergogenic aid in racehorses. This study was undertaken to investigate the changes in exercise capacity in maturing horses in a training programme, and to assess whether eST is an ergogenic aid to this group. We tested the hypothesis that the combination of training and eST, compared to training alone, would further improve exercise capacity in maturing Standardbreds, by virtue of ST's anabolic effects and potential to enhance cardiac function, circulating fluid volume and red cell mass. Twel...
