Treadmill exercise for horses involves the use of a controlled mechanical platform to simulate various gaits and intensities of physical activity. This form of exercise allows for consistent and measurable training conditions, which can be used for rehabilitation, fitness assessment, and performance enhancement. Treadmill exercise facilitates the study of equine locomotion, respiratory function, and cardiovascular response under standardized conditions. It is also utilized in research to evaluate the effects of different training regimens and to investigate metabolic and physiological responses to exercise. This page compiles peer-reviewed research studies and scholarly articles that explore the methodology, applications, and implications of treadmill exercise in equine practice.
McKane SA, Slocombe RF.Histological studies of exercise-induced pulmonary haemorrhage (EIPH) reveals inflammatory infiltrates within areas of lung that contain haemorrhage. This has resulted in the hypothesis that pulmonary inflammation could cause EIPH or contribute to an increased risk or severity of EIPH. Objective: To determine whether experimentally-induced pulmonary inflammation predisposes the lung to haemorrhage during exercise, by evaluating the bronchoalveolar lavage (BAL) cytology of normal and inflamed regions of lung following high speed treadmill exercise. Methods: Transendoscopic airway inoculations o...
Trachsel DS, Bitschnau C, Waldern N, Weishaupt MA, Schwarzwald CC.Frequent supraventricular or ventricular arrhythmias during and after exercise are considered pathological in horses. Prevalence of arrhythmias seen in apparently healthy horses is still a matter of debate and may depend on breed, athletic condition and exercise intensity. Objective: To determine intra- and interobserver agreement for detection of arrhythmias at rest, during and after exercise using a telemetric electrocardiography device. Methods: The electrocardiogram (ECG) recordings of 10 healthy Warmblood horses (5 of which had an intracardiac catheter in place) undergoing a standardised ...
Crook TC, Wilson A, Hodson-Tole E.Locomotion requires successful negotiation of different terrains, but we currently know little of how the musculoskeletal system adapts to cope with positive and negative slopes. Objective: To compare the effects of treadmill speed and gradient on equine hindlimb muscle mean electromyographic (EMG) intensity. Methods: Surface EMG recorded the activity of gluteus medius (GM), biceps femoris (BF), vastus lateralis (VL), gastrocnemius lateralis (GL) and extensor digitorum longus (EDL) in 6 horses at walk (1.4-1.6 m/s) and trot (2.6-3 m/s) on 3 different treadmill gradients (0, 10% and -10%). Sign...
Meyer ND, Bayly WM, Sides RH, Wardrop KJ, Slinker BK.Prolonged equine exercise can cause hypochloraemic alkalosis and hypokalaemia secondary to the loss of hypertonic sweat. Movement of ions in and out of erythrocytes during exercise may help regulate acid-base balance and changes in plasma ion concentrations. The extent to which this happens during prolonged equine exercise has not been reported. Objective: To measure changes in blood gases and major plasma and intraerythrocytic (iRBC) ion concentrations of horses undergoing prolonged submaximal exercise. Methods: Six horses were trotted at ∼ 30% VO2max on a treadmill for 105 min. Arterial ((...
Weishaupt MA, Hogg HP, Auer JA, Wiestner T.Gait analysis parameters are sensitive to alterations in velocity. For comparison of nonspeed-matched data, the velocity dependency needs to be known. Objective: To describe the changes in gait pattern and determine the relationships between stride duration, vertical impulse, contact time and peak vertical force within a range of walking and trotting speeds. Methods: Thirty-eight nonlame Warmblood horses were subjected to an incremental speed test. The spans of speed were adjusted individually to each horse and ranged from 1.1-2.1 m/s at walk and from 2.5-5.8 m/s at trot. Time, force and spati...
Zsoldos RR, Kotschwar A, Kotschwar AB, Rodriguez CP, Peham C, Licka T.The rectus abdominis (RA) and oblique external abdominal (OEA) muscles are both part of the construction of the equine trunk and thought to be essential for the function of the spine during locomotion. Although RA activity at trot has previously been investigated, the relationship between OEA and RA at walk and trot has not yet been described. Objective: To document abdominal muscle activities during walk and trot, and test the hypothesis that muscle activity at walk would be smaller than at trot. Methods: Six horses (8-20 years old, 450-700 kg) were used for surface electromyography (EMG) mea...
Ramseyer A, Sides R, Slinker B, Evans D, Bayly W.The ability to obtain breath-by-breath measures of ventilatory mechanics for the entirety of an exercise test, regardless of speed(s) or duration enables evaluations of equine ventilation during exercise that are necessary for assessments of performance. Objective: Evaluation of a new ergospirometer (Quadflow; QF) system's accuracy and repeatability for measuring pulmonary variables in contrast to the established pneumotachometer-based system (control) and assessment of its effects, if any, on exercise capacity at high speeds. Methods: Five Thoroughbred horses each performed 10 incremental exe...
Treiber KH, Boston RC, Geor RJ, Hess TM, Harris PA, Kronfeld DS.Tools and criteria to evaluate and understand glucose metabolism are essential to optimise equine energy utilisation for exercise performance and reduced metabolic health risks. Objective: To re-evaluate models of glucose kinetics in the horse at rest and during endurance type exercise using a single injection technique and compartmental modelling. Methods: Twelve exercise trained Arabian geldings received a bolus of 100 µmol/kg bwt [6,6-(2) H]glucose i.v. while at rest and while running at ∼ 4 m/s on a treadmill. Tracer and tracee glucose curves from 4-150 min after the bolus dose (while t...
Takahashi T, Yoshihara E, Mukai K, Ohmura H, Hiraga A.Although the main cause of injury to the superficial digital flexor tendon (SDFT) is assumed to be high intensity loading of the tendon, to date the forces exerted on the SDFT during cantering have never been measured. Objective: To measure the force exerted on the SDFT at walk, trot and canter on a treadmill. Methods: Arthroscopically implantable force probes (AIFP) were implanted in the SDFT of the left and right forelimbs of 8 Thoroughbred horses (480-565 kg). The output of the AIFP was calibrated using the SDFT force calculated by inverse dynamics and an in vitro model of the lower forelim...
Minetti AE, Cisotti C, Mian OS.Although the 3D trajectory of the body centre of mass during ambulation constitutes the 'locomotor signature' at different gaits and speeds for humans and other legged species, no quantitative method for its description has been proposed in the literature so far. By combining the mathematical discoveries of Jean Baptiste Joseph Fourier (1768-1830, analysis of periodic events) and of Jules Antoine Lissajous (1822-1880, parametric equation for closed loops) we designed a method simultaneously capturing the spatial and dynamical features of that 3D trajectory. The motion analysis of walking and r...
Yamano S, Kawai M, Minami Y, Hiraga A, Miyata H.We evaluated differences in muscle fiber recruitment patterns between continuous and interval training to develop an optimal training program for Thoroughbred horses. Five well trained female thoroughbred horses (3-4 years old) were used. The horses performed two different exercises on a 10% inclined treadmill: 90%VO2 max for 4 min (continuous) and 90% VO2 max for 2 min × 2 times with 10-min interval (interval). Muscle samples were obtained from the middle gluteal muscle before and immediately after the exercises. Four muscle fiber types (type I, IIA, IIA/X, and IIX) were immunohistochemicall...
Campbell EH.Equine conditioning programmes are rarely driven by science. Indeed, the scientific literature on conditioning responses often refers to conventional technique rather than physiological driving parameters. This, alongside poor classification of conditioning protocols, has reduced the possibility of comparative data analysis. Recent interest into lactate-driven conditioning programmes has driven this review which provides a summary of equine protocols used to date and their responses. Key areas identified for further standardisation and/or investigation include (1) the treadmill acclimation pro...
Davidson EJ, Martin BB, Boston RC, Parente EJ.Although well documented in racehorses, there is paucity in the literature regarding the prevalence of dynamic upper airway abnormalities in nonracing performance horses. Objective: To describe upper airway function of nonracing performance horses with abnormal respiratory noise and/or poor performance via exercising upper airway videoendoscopy. Methods: Medical records of nonracing performance horses admitted for exercising evaluation with a chief complaint of abnormal respiratory noise and/or poor performance were reviewed. All horses had video recordings of resting and exercising upper airw...
Barakzai SZ, Dixon PM.To correlate resting and exercising endoscopic grades of laryngeal function in horses undergoing high-speed treadmill endoscopy (HSTE) using the Havemeyer grading system. To correlate dorsal displacement of the soft palate (DDSP) seen at rest with palatal function during exercise. Methods: Records of horses that underwent HSTE examination (1999-2009) were reviewed. Resting laryngeal function score and other abnormalities noted on resting endoscopy were recorded as were results of HSTE. Results of resting and exercising endoscopic findings were correlated. Results: 281 horses underwent HSTE. Th...
Lindner A, López RA, Durante E, Hernandez H, Botta V, Sadaba S, Boffi FM.This study examined the effect of exercising horses five times per fortnight with two bouts of 5 min duration at their v(10) with 2 days between consecutive exercise sessions. Five Anglo-Arabian horses were treadmill-conditioned for 6 weeks. A standardized exercise test (SET) was performed at the beginning of the conditioning period (CP) to determine the blood lactate-running speed (BLRS) and the heart rate-running speed (HRRS) relationship and the SET was repeated every 2 weeks. After each SET, the BLRS relation was used to calculate the horse's speed (v = velocity), which produced a blood la...
Garrett KS, Woodie JB, Embertson RM.Assessment of arytenoid movement has traditionally been performed using upper airway (UA) endoscopy. However, recent work suggests that laryngeal ultrasonography may provide additional complementary information. Objective: To determine the value of laryngeal ultrasonography for the diagnosis of recurrent laryngeal neuropathy in the horse. Objective: Horses with abnormal arytenoid movement (AM) during treadmill UA endoscopy would have increased echogenicity of the left cricoarytenoideus lateralis muscle (CALM) and smaller left CALM and vocalis size while horses with normal AM during treadmill U...
Fey K.Horses are obligate nasal breathers and depend on patency of their nasal passages. Several dynamic obstructive diseases in the pharyngeal and laryngeal area can be differentiated by high speed treadmill endoscopy and may be responsible for impaired exercise tolerance in the equine athlete. The anatomical specialty of guttural pouches predisposes the horse to species-specific diseases.
Schefer KD, Bitschnau C, Weishaupt MA, Schwarzwald CC.Stress echocardiography is used to diagnose myocardial dysfunction in horses, but current methods are not well standardized. The influence of heart rate (HR) on measurements is largely unknown. Objective: To investigate the use of 2-dimensional echocardiography (2DE), anatomical M-mode (AMM), tissue Doppler imaging (TDI), and 2D speckle tracking (2DST) at rest and after exercise for quantification of regional and global left-ventricular (LV) function. Methods: Five athletic Warmblood horses; 11.6+/-3.6 years; 529+/-48 kg. Methods: Prospective study. Three separate echocardiographic examination...
Byström A, Rhodin M, von Peinen K, Weishaupt MA, Roepstorff L.The kinematics of the saddle and rider have not been thoroughly described at the walk. Objective: To describe saddle and rider movements during collected walk in a group of high-level dressage horses and riders. Methods: Seven high-level dressage horses and riders were subjected to kinematic measurements while performing collected walk on a treadmill. Movements of the saddle and rider's pelvis, upper body and head were analysed in a rigid body model. Projection angles were determined for the rider's arms and legs, and the neck and trunk of the horse. Distances between selected markers were use...
Baragli P, Pacchini S, Gatta D, Ducci M, Sighieri C.Four untrained standardbred horses performed a standardized exercise test on the treadmill and an automated blood collection system programmed to obtain blood samples every 15 s was used for blood collection in order to evaluate the kinetics of adrenaline and noradrenaline. The highest average values obtained for adrenaline and noradrenaline were 15.0 +/- 3.0 and 15.8 +/- 2.8 nmol/l respectively, with exponential accumulation of adrenaline (r = 0.977) and noradrenaline (r = 0.976) during the test. Analysis of the correlation between noradrenaline and adrenaline for each phase of the test shows...
Borgia LA, Valberg SJ, McCue ME, Pagan JD, Roe CR.To evaluate effects of fats with odd and even numbers of carbon atoms on muscle metabolism in exercising horses with polysaccharide storage myopathy (PSSM). Methods: 8 horses with PSSM (6 females and 2 males; mean +/- SD age, 6.3 +/- 3.9 years). Methods: Isocaloric diets (grain, triheptanoin, corn oil, and high-fat, low-starch [HFLS] feed) were fed for 3 weeks each; horses performed daily treadmill exercise. Grain was fed to establish an exercise target, and HFLS feed was fed as a negative control diet. Daily plasma samples were obtained. For each diet, a 15-minute exercise test was performed,...
Lindner AE.The speed producing the maximal lactate steady state (maxLASS) is supposed to be the optimal speed to condition for endurance. The maxLASS was defined as the maximal speed at which the blood lactate concentration ([LA]) between the 5th and the 25th min of continuous exercise did not increase by more than 1 mmol/L. According to the aerobic-anaerobic lactate threshold concept determined in humans, maxLASS corresponds to v(4) [speed in a standardized exercise test (SET) shown to produce an [LA] of 4 mmol/L; generalized to v(i) for the speed producing an [LA] of i mmol/L]. Four Thoroughbreds were ...
Kotschwar AB, Baltacis A, Peham C.Saddle pads are widely used in riding sports but their influence on saddle pressures is poorly understood. Objective: To evaluate the forces acting on the horse's back, and the eventual pressure distribution by using different saddle pads underneath a fitting saddle. Methods: Sixteen sound horses of different breeds and ages were ridden on a treadmill at walk and sitting trot. The horses were wearing a dressage saddle with a fitting saddle tree and 4 different saddle pads (gel, leather, foam and reindeer fur) successively. For comparison, measurements were made without any saddle pad. Right fo...
McGivney BA, Eivers SS, MacHugh DE, MacLeod JN, O'Gorman GM, Park SD, Katz LM, Hill EW.Selection for exercise-adapted phenotypes in the Thoroughbred racehorse has provided a valuable model system to understand molecular responses to exercise in skeletal muscle. Exercise stimulates immediate early molecular responses as well as delayed responses during recovery, resulting in a return to homeostasis and enabling long term adaptation. Global mRNA expression during the immediate-response period has not previously been reported in skeletal muscle following exercise in any species. Also, global gene expression changes in equine skeletal muscle following exercise have not been reported...
Wennerstrand J, Gómez Alvarez CB, Meulenbelt R, Johnston C, van Weeren PR, Roethlisberger-Holm K, Drevemo S.Back problems are important contributors to poor performance in sport horses. It has been shown that kinematic analysis can differentiate horses with back problems from asymptomatic horses. The underlying mechanism can, however, only be identified in a uniform, experimental setting. Our aim was to determine if induction of back pain in a well-defined site would result in a consistent change in back movement. Back kinematics were recorded at a walk and trot on a treadmill. Unilateral back pain was then induced by injecting lactic acid into the left longissimus dorsi muscle. Additional measureme...
Minami Y, Yamano S, Kawai M, Hiraga A, Miyata H.To find a new parameter indicating muscle fitness in Thoroughbred horses, we examined time-dependent recovery of glycogen content and sarcoplasmic reticulum (SR) Ca(2+)-ATPase activity of skeletal muscle after intensive treadmill running. Two repeated 50-sec running sessions (13 m/sec) were performed on a flat treadmill (approximately 90%VO2max). Muscle samples of the middle gluteal muscle were taken before exercise (pre) and 1 min, 20 min, 60 min, and 24 hr after exercise. Muscle fiber type composition was determined in the pre muscle samples by immunohistochemical staining with monoclonal an...
Hubbell JA, Sams RA, Schmall LM, Robertson JT, Hinchcliff KW, Muir WW.Increased doses of detomidine are required to produce sedation in horses after maximal exercise compared to calm or resting horses. Objective: To determine if the pharmacokinetics of detomidine in Thoroughbred horses are different when the drug is given during recuperation from a brief period of maximal exercise compared to administration at rest. Methods: Six Thoroughbred horses were preconditioned by exercising them on a treadmill. Each horse ran a simulated race at a treadmill speed that caused it to exercise at 120% of its maximal oxygen consumption. One minute after the end of exercise, h...
Leprêtre PM, Metayer N, Giovagnoli G, Pagliei E, Barrey E.Measurements of minute ventilation (VE) and expired oxygen and carbon dioxide fractions (FeO2 and FeCO2) were measured at rest and during exercise in seven warmblood horses performing two consecutive standardised incremental treadmill exercise tests at submaximal speed, using the portable K4b2 telemetric unit and the laboratory Quark metabolic cart in random order. Oxygen consumption (VO2) and carbon dioxide production (VCO2) were estimated using the Haldane equation. There were no significant differences between the measurements made with the two devices. However, VE was overestimated when th...
van den Burg MM, Eizema K, de Graaf-Roelfsema E, van Breda E, Wijnberg ID, van der Kolk JH, Everts ME.To investigate the effects of acute exercise and long-term training on Na(+),K(+)-ATPase content, mRNA isoforms, and protein concentration in equine muscle. Methods: 6 Standardbreds. Methods: Horses performed a bout of exercise on a treadmill before and after 18 weeks of combined interval and endurance training. Muscle biopsy specimens were obtained from vastus lateralis muscle (VLM) and pectoralis descendens muscle (PDM) before and after exercise. The Na(+),K(+)-ATPase content, mRNA isoforms, and protein concentrations were determined by use of [(3)H]ouabain binding, real-time PCR assay, and ...
Lindner A, Mosen H, Kissenbeck S, Fuhrmann H, Sallmann HP.The velocity at which blood lactate concentration ([LA]) of 4 mmol/L is reached (v(4)) is widely used to determine fitness, but there are few published data on using [LA] as a guide for the exercise speed for training in horses. In this study, the effect of 3 conditioning programs with [LA] guided exercise speeds on v(4), v(200) (speed at a heart rate of 200 beats/min), blood [LA], plasma FFA ([FFA]), and alanine concentrations ([alanine]), before and after exercise, as well as heart rate during exercise, of horses was examined. Six 2-yr-old Haflinger stallions underwent an initial treadmill-b...
Art T, Lekeux P.Five healthy, fit Standardbreds (mean +/- SEM, 490.4 +/- 15.0 kg, 4.0 +/- 0.5 years) were studied during a standardized test carried out on a treadmill. The test consisted of an 8-minute warm-up and a 9-minute exercise period (1 minute at 1.7, 4, 7, 8, 9, and 10 m/s; 2 minutes at 4 m/s; and a 1-minute walk at a 6% slope). Respiratory airflow, tidal volume (V(T)), and respiratory frequency (f) were continuously recorded, using 2 ultrasonic pneumotachographs connected to a face mask and mass spectrometer. Oxygen uptake, carbon dioxide output, and expired minute volume (V(E)) were obtained on a b...
McCutcheon LJ, Geor RJ, Hinchcliff KW.This study examined changes in skeletal muscle GLUT4 content and glucose transport in isolated muscle membranes (GT) from horses before and 2 min after standardised submaximal exercise tests (SET) prior to and after completion of 6 weeks of training. Seven horses, age 3-9 years, body mass mean +/- s.e. 530 +/- 19 kg, and sedentary for at least 4 months, completed 6 weeks of training on a treadmill. An initial SET (UT) was performed on a 4 degree incline at a speed equivalent to 55% of pretraining VO2max and was repeated post-training at the same absolute workload (ABS). A third SET (REL) was p...
Wickler SJ, Hoyt DF, Cogger EA, Hall KM.Horses have a tendency to utilize a relatively narrow set of speeds near the middle of a much broader range they are capable of using within a particular gait, i.e., a preferred speed. Possible explanations for this behavior include minimizing musculoskeletal stresses and maximizing metabolic economy. If metabolic economy (cost of transport, CT) and preferred speeds are linked, then shifts in CT should produce shifts in preferred speed. To test this hypothesis, preferred speed was measured in trotting horses (n = 7) unloaded on the level and loaded with 19% of their body weight on the level. T...
Colborne GR, Birtles DM, Cacchione IC.Muscle fatigue can be quantified using Fourier analysis of the recorded EMG signal. Median frequency is the frequency at which the Fourier profile is bisected, and this measure typically shifts to smaller values during fatigue. This technique was combined with kinematic analysis to describe the time course of fatigue in horses galloping on an inclined treadmill. It was hypothesised that EMG median frequency would decrease in tandem with changes in kinematic variables through the exercise test. Three fit Thoroughbred horses had retroreflective markers placed on their hooves and withers. Surface...
Kamm JL, Frisbie DD, McIlwraith CW, Orr KE.To use microarray analysis to identify genes that are differentially expressed in horses with experimentally induced osteoarthritis. Methods: 24 horses. Methods: During arthroscopic surgery, a fragment was created in the distal aspect of the radiocarpal bone in 1 forelimb of each horse to induce osteoarthritis. At day 14 after osteoarthritis induction, horses began exercise on a treadmill. Blood and synovial fluid samples were collected before and after surgery. At day 70, horses were euthanized and tissues were harvested for RNA analysis. An equine-specific microarray was used to measure RNA ...
Howard RD, McIlwraith CW, Trotter GW, Powers BE, McFadden PR, Harwood FL, Amiel D.Bilateral osteochondral defects (10 mm2 x 3 mm deep) were created on the distal articular surface of the radial carpal bone of ten, 2- to 3-year-old horses. One defect of each horse was repaired, using a sternal cartilage autograft (treated), and the other was left untreated (control). The horses were exercised on a high-speed treadmill at incrementally increased speed and duration over the course of 12 months. Horses were evaluated arthroscopically at 6 to 7 weeks, and clinical examinations were conducted weekly at exercise. Twelve months after surgery, carpuses of each horse were radiographe...
von Peinen K, Wiestner T, Bogisch S, Roepstorff L, van Weeren PR, Weishaupt MA.The exact relationship between the saddle pressure pattern during one stride cycle and the movements of horse and rider at the walk are poorly understood and have never been investigated in detail. Objective: The movements of rider and horse account for the force distribution pattern under the saddle. Methods: Vertical ground reaction forces (GRF), kinematics of horse and rider as well as saddle forces (FS) were measured synchronously in 7 high level dressage horses while being ridden on an instrumented treadmill at walk. Discrete values of the total saddle forces (FStot) were determined for e...
Parks CM, Manohar M.Transmural distribution of myocardial blood flow and coronary vasodilator reserve (15-microns-diam radionuclide-labeled microspheres) was studied in 11 adult, healthy ponies at rest and during moderate and severe exercise performed on a treadmill (heart rate 56 +/- 4, 154 +/- 3, and 225 +/- 7 beats . min-1, respectively.). Exercise resulted in a marked increase in cardiac output, mean aortic pressure, right ventricular (RV) systolic and end-diastolic pressure, left ventricular (LV) end-diastolic pressure, and the maximum rate of rise of LV pressure LV (dP/dtmax). Accompanying these changes was...
De Maré L, Boshuizen B, Vidal Moreno de Vega C, de Meeûs C, Plancke L, Gansemans Y, Van Nieuwerburgh F, Deforce D, de Oliveira JE, Hosotani G....There is a great need for objective external training load prescription and performance capacity evaluation in equestrian disciplines. Therefore, reliable standardised exercise tests (SETs) are needed. Classic SETs require maximum intensities with associated risks to deduce training loads from pre-described cut-off values. The lactate minimum speed (LMS) test could be a valuable alternative. Our aim was to compare new performance parameters of a modified LMS-test with those of an incremental SET, to assess the effect of training on LMS-test parameters and curve-shape, and to identify the optim...
Keegan KG, Wilson DA, Smith BK, Wilson DJ.To determine whether kinematic changes induced by heel pressure in horses differ from those induced by toe pressure. Methods: 10 adult Quarter Horses. Methods: A shoe that applied pressure on the cuneus ungulae (frog) or on the toe was used. Kinematic analyses were performed before and after 2 levels of frog pressure and after 1 level of toe pressure. Values for stride displacement and time and joint angles were determined from horses trotting on a treadmill. Results: The first level of frog pressure caused decreases in metacarpophalangeal (fetlock) joint extension during stance and increases ...
Back W, Schamhardt HC, Barneveld A.The canter is a 3 beat asymmetrical gait with a difference in timing between left and right limbs. To evaluate intralimb asymmetry at the canter, a group of 24 Dutch Warmbloods was evaluated on a treadmill (7 m/s) using a modified CODA-3 optoelectronic gait analysis system. Thirteen horses cantered in the left lead ('leading limb' group) and 11 in the right lead ('trailing limb' group) during left forelimb recordings, while 11 horses were at the left and 13 were at the right lead during left hindlimb recordings. Kinematic differences between horses from the 'leading limb' and 'trailing limb' g...
Ohmura H, Mukai K, Takahashi Y, Takahashi T, Jones JH.Hypoxic training is effective for improving athletic performance in humans. It increases maximal oxygen consumption (V̇Omax) more than normoxic training in untrained horses. However, the effects of hypoxic training on well-trained horses are unclear. We measured the effects of hypoxic training on V̇Omax of 5 well-trained horses in which V̇Omax had not increased over 3 consecutive weeks of supramaximal treadmill training in normoxia which was performed twice a week. The horses trained with hypoxia (15% inspired O) twice a week. Cardiorespiratory valuables were analyzed with analysis of varia...
Mukai K, Hiraga A, Takahashi T, Matsui A, Ohmura H, Aida H, Jones JH.OBJECTIVE To determine whether racehorses undergoing regular exercise at 2 intensities or stall rest during a period of reduced training (detraining) would differentially maintain their cardiopulmonary and oxygen-transport capacities. ANIMALS 27 Thoroughbreds. PROCEDURES Horses trained on a treadmill for 18 weeks underwent a period of detraining for 12 weeks according to 1 of 3 protocols: cantering at 70% of maximal rate of oxygen consumption ([Formula: see text]o) for 3 min/d for 5 d/wk (canter group); walking for 1 h/d for 5 d/wk (walk group); or stall rest (stall group). Standardized treadm...
Hopkins SR, Bayly WM, Slocombe RF, Wagner H, Wagner PD.During short-term maximal exercise, horses have impaired pulmonary gas exchange, manifested by diffusion limitation and arterial hypoxemia, without marked ventilation-perfusion (VA/Q) inequality. Whether gas exchange deteriorates progressively during prolonged submaximal exercise has not been investigated. Six thoroughbred horses performed treadmill exercise at approximately 60% of maximal oxygen uptake until exhaustion (28-39 min). Multiple inert gas, blood-gas, hemodynamic, metabolic rate, and ventilatory data were obtained at rest and 5-min intervals during exercise. Oxygen uptake, cardiac ...
Bodó G, Hangody L, Szabó Z, Peham C, Schinzel M, Girtler D, Sótonyi P.An 11-year-old, Hungarian half-bred stallion was presented with a history of mixed left hindlimb lameness of 6 months duration. Subchondral bone cyst of the medial femoral condyle and injury of the medial meniscus were diagnosed. Osteochondral autograft transplantation (mosaic arthroplasty) was performed, taking grafts from the less weight-bearing medial border of the medial femoral trochlea of the affected limb, and transplanting them into the cyst during arthroscopy. The lameness was evaluated prior to and one year after the operation with a motion analysis system during treadmill exercise. ...
Hodgson DR, Rose RJ, Kelso TB, McCutcheon LJ, Bayly WM, Gollnick PD.Thoroughbred horses were exercised to fatigue on a treadmill at 62% and 100% of their VO2max. Hypoxemia occurred at the onset of exercise under both exercise conditions. This hypoxemia persisted to fatigue during the heavy exercise but progressively diminished as the exercise continued and had disappeared by the end of exercise at the lighter load. As a result of the hypoxemia the oxygen content of arterial blood during exercise at VO2max was 17% below its carrying capacity. However, under both experimental conditions the CaO2 still exceeded that of rest owing to an elevation in hemoglobin con...
Jones JH, Taylor CR, Lindholm A, Straub R, Longworth KE, Karas RH.This study assessed the degree to which correcting blood gas measurements to rectal temperature (Tre) rather than to the temperatures at which gas exchange occurs [pulmonary arterial (Tpa) or intramuscular (Tm)] introduces errors into blood gas analysis of exercising mammals. Horses and steers weighing 450 kg were run on a treadmill at speeds up to those eliciting maximal rates of O2 consumption (VO2max), and temperatures were measured in various body compartments. In both species Tpa rose faster than Tre during the run, the degree of dissociation being a function of exercise intensity and dur...
Fraipont A, Van Erck E, Ramery E, Fortier G, Lekeux P, Art T.A field test and a standardized treadmill test were used to assess fitness in endurance horses. These tests discriminated horses of different race levels: horses participating in races of 120 km and more showed higher values of VLA4 (velocity at which blood lactate reached 4 mmol/L) and V200 (velocity at which heart rates reached 200 beats per min) than horses of lower race levels. Un test sur le terrain et un test sur tapis roulant ont été utilisés pour évaluer la condition physique des chevaux d’endurance. Ces tests ont séparé les chevaux de différents niveaux de course : les cheva...
McKenzie EC, Valberg SJ, Godden SM, Finno CJ, Murphy MJ.To determine the effect of oral administration of dantrolene sodium on serum creatine kinase (CK) activity after exercise in horses with recurrent exertional rhabdomyolysis (RER). Methods: 2 healthy horses and 5 Thoroughbreds with RER. Methods: 3 horses received 2 doses of dantrolene (4, 6, or 8 mg/kg, p.o., with and without withdrawal of food) 2 days apart; 90 minutes after dosing, plasma dantrolene concentration was measured spectrofluorometrically. On the basis of these results, 5 Thoroughbreds with RER from which food was withheld received dantrolene (4 mg/kg) or an inert treatment (water ...
Bond SL, Greco-Otto P, Sides R, Kwong GPS, Léguillette R, Bayly WM.A prospective, randomized, controlled study was designed to determine relative aerobic and anaerobic (lactic and alactic) contributions at supramaximal exercise intensities using two different methods. Thoroughbred racehorses ( = 5) performed a maximal rate of oxygen consumption (V̇o) test and three supramaximal treadmill runs (105, 115, and 125% V̇o). Blood lactate concentration (BL) was measured at rest, every 15 s during runs, and 2, 5, 10, 20, 30, 40, 50, and 60 min postexercise. In , oxygen demand was calculated for each supramaximal intensity based on the V̇o test, and relative aerobi...
Weishaupt MA, Wiestner T, Hogg HP, Jordan P, Auer JA, Barrey E.The purpose of this study was to verify the sensitivity of 2 gait analysis methods in detecting subtle lameness and to compare the results to the traditional orthopaedic evaluation. Twenty-two horses were evaluated (1) subjectively by 3 different experienced clinicians and (2) objectively with synchronised ground reaction force and accelerometric gait measurements on a treadmill. The horses were assigned for each of the 3 methods independently to one of 3 groups (GR): sound, lameness front limb, lameness hindlimb. Additionally, for each horse, the affected limb (AL) and degree of lameness (DL)...
Broeckx SY, Pille F, Buntinx S, Van Brantegem L, Duchateau L, Oosterlinck M, Chiers K, Bertone AL, Spaas JH, Martens AM.OBJECTIVE To evaluate lameness and morphological changes associated with an osteochondral fragment-groove procedure as a means of experimental induction of metacarpophalangeal (MCP) joint osteoarthritis within an 11-week period in horses. ANIMALS 6 nonlame adult warmbloods. PROCEDURES The right MCP joint of each horse underwent an osteochondral fragment-groove procedure (day 0). After 1 week of stall rest (ie, starting day 7), each horse was trained daily on a treadmill. Weekly, horses underwent visual and inertial sensor-based assessments of lameness. Both MCP joints were assessed radiographi...
Marlin DJ, Allen JC.Knowledge of the competitive demands of different sports or activities is important for designing appropriate training programmes to ensure that animals reach a sufficient level of fitness to reduce the risk of overexertion and injury or illness and to achieve the best possible performance in relation to an individual's genetic potential. Whilst the physiological demands of many equestrian sports have been described, to the best of our knowledge the cardiovascular demands of polo have not. The aims of the present study were therefore to record heart rate during and after competitive polo games...
Forster HV, Pan LG, Bisgard GE, Kaminski RP, Dorsey SM, Busch MA.We studied the effect of changes in inspired [O2] on partial pressure of CO2 in arterial blood (PaCO2) during treadmill exercise (3 mph, 3% grade) in normal, acute (+2-4 wk), and chronic (+1-2 yr) carotid body-denervated (CBD) ponies. In all studies, PaCO2 decreased (P less than 0.01) from rest during exercise, reaching a nadir usually between 15 and 30 s of exercise. During normoxia [partial pressure of O2 in arterial blood (PaO2) approximately 95 Torr], the PaCO2 nadir was 2.3 +/- 0.6 Torr below resting level in normal ponies, but the nadir was greater (P less than -0.01) in acute (delta = 6...
Langsetmo I, Weigle GE, Fedde MR, Erickson HH, Barstow TJ, Poole DC.The horse is a superb athlete, achieving a maximal O2 uptake (approximately 160 ml . min-1 . kg-1) approaching twice that of the fittest humans. Although equine O2 uptake (VO2) kinetics are reportedly fast, they have not been precisely characterized, nor has their exercise intensity dependence been elucidated. To address these issues, adult male horses underwent incremental treadmill testing to determine their lactate threshold (Tlac) and peak VO2 (VO2 peak), and kinetic features of their VO2 response to "square-wave" work forcings were resolved using exercise transitions from 3 m/s to a below...
Cruz AM, Maninchedda UE, Burger D, Wanda S, Vidondo B.OBJECTIVE To determine repeatability of gait variables measured by use of extremity-mounted inertial measurement units (IMUs) in nonlame horses during trotting under controlled conditions of treadmill exercise. ANIMALS 10 horses. PROCEDURES Six IMUs were strapped to the metacarpal, metatarsal, and distal tibial regions of each horse. Data were collected in a standardized manner (3 measurements/d on 3 d/wk over a 3-week period) while each horse was trotted on a treadmill. Every measurement consisted of a minimum of 20 strides from which a minimum of 10 strides was selected for analysis. Spatial...
Snow DH, Harris RC, MacDonald IA, Forster CD, Marlin DJ.In Study 1, a single speed test of 6 to 12 m/sec was performed for 2 mins at an incline of 5 degrees on a high-speed treadmill (single-step test). Only one speed was performed per session and blood samples were taken before and after the test. In Study 2 horses cantered for 1 min at increasing speeds of 6 to 13 m/sec on an incline of 3 degrees (multiple-step test). Blood samples were taken before exercise, throughout the test and during recovery. In the single-step test plasma concentrations of adrenaline and noradrenaline both increased at speeds of 9 m/sec, as did blood lactate. Mean concent...
Jose-Cunilleras E, Young LE, Newton JR, Marlin DJ.The prevalence and severity of cardiac arrhythmias during exercise in athletic horses presented for poor performance is not well described. Objective: To describe prevalence and severity of ventricular and supraventricular arrhythmias immediately before, during and immediately after standardised incremental treadmill exercise tests (IET) to fatigue in Thoroughbred horses during investigation of poor performance. Methods: The electrocardiograms (ECG) of 88 Thoroughbred racehorses, judged to be free of significant heart disease or arrhythmia at rest, were used. A modified base-apex ECG was recor...
Nyman S, Jansson A, Lindholm A, Dahlborn K.In the present study, the main objective was to study factors affecting postexercise voluntary water intake in horses. Four Standardbred horses (mean +/- s.e. bwt 500 +/- 8 kg) were used to study water intake and effects of altering hydration status before an incremental exercise test (INCR) and a 40 min constant velocity exercise test (CONST) on a treadmill. Exercise was performed during normohydration (N), after dehydration for 24 h (DEH) and after hyperhydration with 12 l water 30 min before exercise (HH). DEH resulted in a bodyweight loss of 3% and there were signs of some fluid uptake pri...
Gottlieb M, Essén-Gustavsson B, Lindholm A, Persson SG.Five Standardbred trotters were trained on a treadmill 3 times/wk for 12 wk by intervals of draft-loaded exercise. The draft load was 34 kp and the velocity approximately 7 m/s. Muscle biopsies were taken from the gluteus medius and longissimus muscles before training and after 2, 4, 8, and 12 wk of training and from the brachiocephalicus muscle before and after training. Both the percentage and the area of type IIa fibers increased and the percentage of type IIb fibers decreased in the gluteus medius muscle during the first 2 wk of training, and then no further significant difference was note...
