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.
Tyler CM, Golland LC, Evans DL, Hodgson DR, Rose RJ.Thirteen standardbred horses were trained as follows: phase 1 (endurance training, 7 wk), phase 2 (high-intensity training, 9 wk), phase 3 (overload training, 18 wk), and phase 4 (detraining, 12 wk). In phase 3, the horses were divided into two groups: overload training (OLT) and control (C). The OLT group exercised at greater intensities, frequencies, and durations than group C. Overtraining occurred after 31 wk of training and was defined as a significant decrease in treadmill run time in response to a standardized exercise test. In the OLT group, there was a significant decrease in body wei...
Rivero JL, Talmadge RJ, Edgerton VR.The histochemical myofibrillar ATPase (mATPase) method is used routinely for identification of equine skeletal muscle fiber types, but important problems have been observed with the subdivision of fast fiber population when using this method. To verify the use of this qualitative method, a number of equine muscle biopsies were analyzed with a combination of histochemical, immunohistochemical, electrophoretic, and morphometric techniques. The influence of training on these interrelations was also evaluated. Methods: Five young (2-3 years old) thoroughbred horses were intensively trained for 8 m...
Evans DL, Golland LC.The aim of this study was to investigate correlations between lactate concentrations in equine whole blood and plasma measured with Accusport1 and Yellow Springs Instruments (YSI2) (2300) methods. The effect of packed cell volume (PCV) on the accuracy of Accusport was also investigated. Blood samples were collected from Thoroughbred horses at 5-10 min intervals after a treadmill exercise test. Blood was added to NaEDTA (for PCV measurement) and to 2 tubes containing lithium heparin anticoagulant (for lactate assays). At concentrations greater than 10 mmol/l, Accusport1 greatly underestimated t...
Holcombe SJ, Derksen FJ, Stick JA, Robinson NE, Boehler DA.To compare tracheal and pharyngeal inspiratory and expiratory pressures achieved during 60 seconds of nasal occlusion in standing horses with pressures achieved in horses during intense exercise. Methods: 5 Standardbreds. Methods: Tracheal and pharyngeal inspiratory and expiratory pressures were obtained from 5 horses during 60 seconds of nasal occlusion and compared with tracheal and pharyngeal pressures achieved during incremental treadmill exercise tests in which horses ran at 50, 75, and 100% of the speed that resulted in maximal heart rate (HRmax). Results: Significant difference was not ...
Weiss DJ, Geor RJ, Burger K.To determine whether pentoxifylline treatment altered hematologic, rheologic, electrolyte, or blood gas test results of Thoroughbreds during submaximal treadmill exercise. Methods: 5 healthy Thoroughbreds that had raced within the past year and had no history of exercise-induced pulmonary hemorrhage. Methods: Mixed venous blood samples were obtained before exercise, at treadmill speeds of 9 and 13 m/s, and 20 minutes after exercise; hematologic, rheologic, electrolyte, and blood gas test results were determined. Results: Pentoxifylline treatment resulted in a 45% reduction in RBC filtration pr...
Stick JA.In this article, videoendoscopy in conjunction with high-speed treadmill exercise and other specialized diagnostic techniques used to measure upper airway function are reviewed as they pertain to the four most commonly diagnosed functional upper airway obstructions: (1) laryngeal hemiplegia, (2) arytenoid chondritis, (3) epiglottic entrapment, and (4) intermittent dorsal displacement of the soft palate. Using experimental and clinical findings obtained with these new instruments and diagnostic techniques, current recommendations for surgery of these obstructions are presented.
Wagner PD, Erickson BK, Seaman J, Kubo K, Hiraga A, Kai M, Yamaya Y.Although the horse is considered an elite athlete with a specific VO2max some 2-4 times higher than man, maximal O2 transport is compromised both by moderately severe arterial desaturation and by failure to extract all O2 from blood perfusing exercising muscle. This prompted the present study to ascertain whether correction of arterial desaturation would proportionally augment VO2max and, if so, would O2 extraction behave in a manner predicted by diffusional transport limitation. Six two year old thoroughbreds were exercised to VO2max on a treadmill each on three separate occasions breathing g...
Gauvreau GM, Young SS, Staempfli H, McCutcheon LJ, Wilson BA, McDonell WN.A valved gas collection system for horses was validated, then used to examine the relationship between the respiratory exchange ratio (RER), and plasma and muscle lactate in exercising horses. Four healthy Standardbred horses were trained to breathe through the apparatus while exercising on a treadmill. Comparisons of arterial blood gas tensions were made at 3 work levels for each horse, without (control), and with the gas collection system present. At the highest work level, the arterial oxygen tension (PaO2) was significantly lower (P < 0.05), and the arterial carbon dioxide tension (PaCO2) ...
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...
Foreman JH, Grubb TL, Benson GJ, Frey LP, Foglia RA, Griffin RL.This study was designed to characterise the acid-base and electrolyte effects of shortening the distance required during steeplechase (Phase B) in the face of hot and humid weather conditions during a treadmill-simulated Speed and Endurance test. Eight conditioned Thoroughbred horses underwent 3 randomised permutations of a standardised exercise test on a high speed treadmill. Each test consisted of trotting at 3.7 m/s for 10 min (Phase A); galloping at 11 m/s (Phase B) for 4 (cool laboratory conditions), 3 (hot and humid), or 2 (hot and humid) min; trotting at 3.7 m/s for 30 min (Phase C); an...
Heck RW, McKeever KH, Alway SE, Auge WK, Whitehead R, Bertone AL, Lombardo JA.The purpose of this study was to determine whether 8 wk of progressive resistance exercise training would produce increases in strength and changes in foreleg muscle characteristics indicative of hypertrophy in ponies. Two mature 3- to 6-yr-old, male ponies (188 +/- 16 kg) were taught to carry sheets of lead over their saddle region (wither) while walking on a level treadmill at 1.9 m.s-1. This initial familiarization period was followed by 8 wk of training (3 d per wk), in which the ponies performed a series of progressive sets of weight carrying to fatigue. Each workout started with a 2-min ...
Weiss DJ, Geor RJ, Burger K.To determine whether furosemide treatment altered the blood flow properties and serum and RBC electrolyte concentrations of Thoroughbreds during submaximal treadmill exercise. Methods: Thoroughbreds were subjected to submaximal treadmill exercise with and without treatment with furosemide (1 mg/kg of body weight, IV). Methods: 5 healthy Throughbreds that had raced within the past year and had no history of exercise-induced pulmonary hemorrhage. Methods: Venous blood samples were obtained before exercise, at treadmill speeds of 9 and 13 m/s, and 10 minutes after exercise, and hemorheologic and ...
The Journal of physiologyApril 15, 1996
Volume 492 ( Pt 2), Issue Pt 2 587-596 doi: 10.1113/jphysiol.1996.sp021331
Lafortuna CL, Reinach E, Saibene F.1. To investigate the effect of locomotor activity on the pattern of breathing in quadrupeds, ventilatory response was studied in four healthy horses during horizontal and inclined (7%) treadmill exercise at different velocities (1.4-6.9 m s(-1)) and during chemical stimulation with a rebreathing method. Stride frequency (f(s)) and locomotor-respiratory coupling (LRC) were also simultaneously determined by means of video recordings synchronized with respiratory events. 2. Tidal volume (V(T)) was positively correlated with pulmonary ventilation (V(E)) but significantly different linear regressi...
Raulo SM, Hyyppa S, Räsänen LA, Pösö AR.The activities of lysosomal enzymes, such as beta-glucuronidase and N-acetyl-beta-D-glucosaminidase, have been shown to increase in muscle after endurance exercise. We examined whether measurable activities of lysosomal enzymes are present in equine plasma and whether the exercise-induced changes in the muscle are reflected in plasma. Six trained Standardbred trotters performed three exercise bouts with 1 h intervals and the same procedure was repeated 3 days later. Venous blood samples and muscle biopsies from the middle gluteal muscle were taken before and after exercise. The activities of b...
Tyler CM, Hodgson DR, Rose RJ.The VO2(max) in racehorses is approximately double that of elite human athletes and the rate of increase in VO2 at the onset of high intensity exercise is much greater than in man. The kinetics of gas exchange are affected by a warm-up prior to exercise in humans, there being a greater aerobic contribution to high intensity exercise after warm-up. Our hypothesis was that a warm-up would increase aerobic energy delivery in racehorses during high intensity exercise. Thirteen fit Standardbred racehorses ran to fatigue at 115% of VO2(max) on a treadmill at 10% slope. Prior to acceleration, horses ...
Holcombe SJ, Beard WL, Hinchcliff KW.To investigate the effect of a mask and pneumotachograph on ventilation, respiratory frequency, and tracheal and nasopharyngeal pressures in horses running on a treadmill. Methods: Six horses ran at 50, 75, and 100% of the speed that resulted in maximum oxygen consumption, with and without a mask and pneumotachograph. Tracheal and pharyngeal inspiratory and expiratory pressures, respiratory frequency, and arterial blood gases were measured. Methods: Six Standardbred horses. Methods: Oxygen consumption was measured during an incremental exercise test to determine the speed that resulted in maxi...
Scheffer CJ, Sloett van Oldruitenborgh-Oosterbaan MM.In the horse, it is important to make a reliable ECG recording during exercise as cardiac arrhythmia is one of the possible causes of poor performance. The purpose of the present study was to obtain a satisfactory, standardized method for ECG recording by computer during a standardized treadmill exercise test and to evaluate the procedure both in healthy and in diseased horses. Ten experienced healthy research horses were used to develop and adapt the original method (for humans) of computerized ECG recording with the Cardio Perfect software program and to obtain reference values for heart rat...
Back W, Schamhardt HC, Barneveld A.In purchase examinations or at studbook selection sales the locomotor apparatus of horses is judged both at walk and trot. To evaluate whether kinematics of the walk are related to the locomotion at the trot, fore and hind limb movements of a group of 24 26-month-old warmbloods were recorded at walk and trot on a treadmill (1.6 and 4 m/s) using a modified CODA-3 gait analysis system. The intralimb coordination patterns at walk and trot were compared, and temporal and spatial variables of these gaits were related. Stride and stance durations (s) were shorter at the trot, while the stance distan...
Buchner HH, Savelberg HH, Schamhardt HC, Barneveld A.The kinematic patterns of all limbs of 11 clinically nonlame Dutch Warmblood horses were studied during induced supporting limb lameness to gain insight into the compensation mechanisms horses use to manage lameness and to test kinematic limb variables for their significance as lameness indicators. Using the locomotion analysis system CODA-3, the kinematics of the horses were recorded while walking (1.6 m/s) and trotting (3.5 m/s) on a treadmill. A transient lameness model, evoking pressure on the hoof sole, was used to induce 3 degrees of fore- and hindlimb lameness. Joint angle patterns and ...
Lund RJ, Guthrie AJ.This study determined the maximal O2 uptake (VO2max) of Thoroughbred horses acclimatised to mild hypobaric conditions using a standard exercise test on a treadmill inclined at a 7% slope. The O2 uptake (VO2) versus speed relationship was linear below the exercise intensity required to attain VO2max. The VO2max of individual horses ranged from 143.5 to 172.6 ml/kg/min. The proportion of total variance for the VO2 versus speed relationship was greater than 0.992, and the coefficients of variation in repeated tests in individual horses ranged between 0.07 and 1.54%. The VO2 versus speed relations...
Harris PA, Marlin DJ, Scott CM, Harris RC, Mills PC, Michell AR, Orme CE, Roberts CA, Schroter RC, Marr CM.Four horses (H, J, N and M) undertook a simulated competition exercise test (CET), designed to simulate physiological and metabolic stresses of the Speed and Endurance (S & E) test of a 3-day-event, under 3 different environmental conditions: 20 degrees C/40% relative humidity (RH) (cool, dry [CD] 2 sessions); 30 degrees C/40% RH (hot, dry [HD]) and 30 degrees C/80% RH (hot, humid [HH]) (Marlin et al. 1995a). Venous blood samples for electrolyte and total protein (TP) determinations were collected from indwelling catheters at predetermined time points throughout each CET and initial 30 min...
Art T, Votion D, Lekeux P.The purpose of this study was 1) to measure and compare some physiological parameters in horses during a standardised treadmill exercise performed either in temperate atmospheric conditions (TC) (ambient temperature: 15 degrees C; relative humidity: 55%), or in hot and humid conditions (HHC) (ambient temperature: 30 degrees C; relative humidity: 75%) and 2) to follow the recovery of the same horses during 1 h after both tests. Five healthy fit Standardbred horses were investigated twice at 8 days interval, in TC and in HHC. Some measurements were made during a standardised treadmill exercise t...
McCutcheon LJ, Geor RJ, Hare MJ, Ecker GL, Lindinger MI.The objective of this study was to determine the composition and extent of sweat losses during submaximal exercise under hot and humid conditions and to compare these findings with the same exercise protocol conducted under cool, dry and hot, dry conditions. Five Thoroughbred horses (age 3 to 6) completed exercise tests under each of 3 environmental conditions in random order: cool, dry (CD), room temperature (T) = 20 degrees C, relative humidity (RH) = 45-55%; hot, dry (HD), T = 32-34 degrees C, RH = 45-55%; and hot, humid (HH), T = 32-34 degrees C, RH = 80-85%. Horses exercised at 50% of the...
Geor RJ, McCutcheon LJ, Ecker GL, Lindinger MI.The objective of this study is to determine the effects of heat, and heat and high relative humidity (RH) on the thermal and cardiorespiratory responses to exercise and recovery. Five Thoroughbred horses (age 3 to 6) completed exercise tests under each of 3 environmental conditions: cool, dry (CD, room temperature (T) = 20 degrees C, RH = 45-55%), hot, dry (HD, T = 32-34 degrees C, RH = 45-55%) and hot, humid (HH, T = 32-34 degrees C, RH = 80-85%). Horses were exercised at a workload equal to 50% of VO2max on a treadmill set at a 10% slope until attainment of a pulmonary artery blood (PA) temp...
Back W, Schamhardt HC, Hartman W, Barneveld A.In literature, it has been hypothesized that the concussion at impact in the equine forelimb is larger than that in the hind limb, and therefore, eventually more clinical lameness may develop in the distal portion of the forelimbs. As the functional anatomy of the distal forelimb and hind limb segments is similar, a study was undertaken to compare the kinematics of hoof and fetlock in the forelimbs and hind limbs. For this purpose, the trot of 24 clinically normal (sound) horses on a treadmill (4 m/s) was recorded, using modern gait analysis equipment. It appeared that vertical hoof velocity a...
Harris PA, Marlin DJ, Mills PC, Roberts CA, Scott CM, Harris RC, Orme CE, Schroter RC, Marr CM, Barrelet F.Four horses (H, J, N and M) undertook a treadmill competition exercise test (CET), designed to simulate the physiological and metabolic stresses of the Speed and Endurance phase of a 3-day-event, under 3 different environmental conditions: 20 degrees C/40% relative humidity (RH) (cool, dry [CD]: 2 sessions); 30 degrees C/40%RH (hot, dry [HD]) and 30 degrees C/80%RH (hot, humid [HH]) (Marlin et al. 1995). A number of subjective clinical observations were made at designated time points throughout the exercise test and initial recovery period including buccal mucous membrane colouration, capillar...
Scheffer CW, Robben JH, Sloet van Oldruitenborgh-Oosterbaan MM.A method for the continuous monitoring of the electrocardiogram (ECG) of horses at rest and during exercise was evaluated in five healthy horses. The horses spent 24 hours in a loose box and performed a standardised exercise test on a treadmill during this period. Two bipolar leads were recorded, lead 1 between the xiphoid and the left withers, and lead 2 between the left ventral thorax and the left dorsal thorax, using disposable electrodes. The quality of the ECGs enabled both an 'operator-controlled' and an automatic analysis to be made. Lead 1 was the most stable during exercise and lead 2...
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...
Parente EJ.The many testing methods available and the increasing sophistication of diagnostic equipment have enhanced greatly our capabilities to diagnose causes of exercise intolerance in the equine athlete during the last several years. High-speed treadmill examination has become the focus of this form of evaluation. Not all clinicians perform or have access to high-speed treadmill examinations. Testing methods that require the use of the high-speed treadmill, as well as methods that do not, are discussed.
King CM, Evans DL, Rose RJ.A standardised incremental exercise test was performed by 9 racehorses with idiopathic laryngeal hemiplegia (ILH), 1 horse with maxillary sinus cysts, 1 horse with epiglottic entrapment, 1 horse with a lesion on the vocal folds, and 1 horse with pharyngitis. Two of the horses with ILH were retested after laryngoplasty and ventriculectomy. The findings were compared with those from 20 normal racehorses. Heart rate, plasma lactate concentration, arterial blood gases, stride frequency, oxygen uptake (VO2) and carbon dioxide production were assessed during treadmill exercise on a +10% slope. The g...
Bayly WM, Leguillette R, Sides RH, Massie S, Guigand C, Jones KB, Warlick LM, Thueson EL, Troudt TA, Slocombe RF, Jones JH.Exercise-induced pulmonary hemorrhage (EIPH) is common in racehorses. Stress failure of the blood-gas barrier causes EIPH when the transmural pulmonary capillary (Pcap)-alveolar pressure difference (Ptm) exceeds the barrier's stress failure threshold. Why Pcap increases is incompletely understood. We hypothesized that alterations in blood volume (BV) could affect left ventricular (LV) and pulmonary arterial wedge (PAW) pressures and Pcap, and correspondingly affect EIPH severity. Six thoroughbreds with EIPH exercised at the same treadmill speed (≈11.9 m/s [11.1, 12.2]; median [IQR]) before (...
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...
Kokkonen UM, Pösö AR, Hyyppä S, Huttunen P, Leppäluoto J.Previous data show that, in horses, plasma atrial natriuretic peptides (ANP and NT-ANP) remain elevated for a long time after exercise. To study whether exercise-induced changes in hormonal and fluid balance explain this, we measured plasma concentrations of COOH- and NH2-terminal atrial natriuretic peptides (ANP(99-129) and NT-ANP(1-98) together with arginine vasopressin (AVP), adrenocorticotrophin (ACTH), beta-endorphin, cortisol, catecholamines, and indicators of fluid balance in six Finnhorses after a graded submaximal exercise test on a treadmill. After exercise, AVP and catecholamines di...
Fjordbakk CT, Holcombe S, Fintl C, Chalmers H, Strand E.Dynamic laryngeal collapse (DLC) associated with poll flexion is a performance limiting dynamic upper airway disorder commonly diagnosed in Coldblooded trotters. An inspiratory obstruction occurs when affected horses are driven with tension on the reins, inducing poll flexion. To date, surgical treatment and conservative management have failed to improve racing performance in affected horses. Objective: To test the efficacy of an external device, the modified checkrein, in limiting poll flexion, diminishing laryngeal collapse and improving airway mechanics when horses are driven on a treadmill...
Dyke TM, Sams RA, Hinchcliff KW.The effects of exercise training on hepatic function in horses were determined by studying the plasma clearance of antipyrine (20 mg/kg iv) in adult mares that either underwent treadmill training for 5 wk (n = 7) or remained in box stalls for the same time period (n = 6). Training consisted of treadmill exercise at 60% (12 min/day) and 90% (3 min/day) of pretraining maximal oxygen consumption (V(O2)max) for 6 days/wk for 5 wk. V(O2)max and velocity to obtain a blood lactate concentration of 4 mmol/l were significantly increased (from 129 to 149 ml x min-1 x kg-1 and from 5.6 to 6.1 m/s, respec...
King CM, Evans DL, Rose RJ.Various cardiorespiratory and metabolic indices were assessed during treadmill exercise in Thoroughbred and Standardbred racehorses with T wave changes in 4 or more leads on the electrocardiogram or second-degree atrio-ventricular (AV) block, and in horses that had no abnormalities on clinical examination, resting electrocardiography or upper respiratory tract endoscopy. No significant differences in heart rate, plasma lactate concentration, arterial blood gases, oxygen uptake, run time, peak velocity, or blood and red cell volumes were found between normal horses and horses with T wave change...
Back W, Schamhardtt HC, Barneveld A, van Weeren PR.Nowadays, ponies are used more and more for competitive equine sports, driving and racing. The locomotor performance of ponies, however, has been evaluated in only a few kinematic and kinetic studies. To compare the longitudinal development of locomotor characteristics in the pony to the same process in the horse, the kinematics of 23 Shetland ponies were recorded at the trot on a treadmill (3 m/s) at ages 4 and 30 months using a modified CODA-3 apparatus. Furthermore, the influence of specific feeding and training regimes on this development was evaluated. It appeared that stride and stance d...
Johnston C, Drevemo S, Roepstorff L.This study investigated the kinematics and kinetics of the carpus during the stance phase. Five Standardbred horses trotted on a treadmill at 8.9 m/s. The kinematics of the horses were filmed and hoof reaction forces (HRF) were recorded. The carpus was overextended throughout most of the stance. There were 2 periods of overextension, a more rapid period in the beginning of the stance and second directly following the first period. Maximal overextension occurred slightly before the second minimum of the braking horizontal HRF. The metacarpal and antebrachial segments rotated counter-clockwise f...
Stick JA, Derksen FJ.Videoendoscopy of the larynx during treadmill exercise was used to determine the surgical treatment of upper airway obstruction in a Standardbred colt. Surgical correction of right-sided laryngeal hemiplegia, first by laryngoplasty, then subtotal arytenoidectomy, was ineffective. Videoendoscopy indicated, and upper airway flow mechanics confirmed, that the laryngeal opening was adequate at rest, but obstruction occurred during exercise. On the basis of the appearance of the larynx during high airflow rates on slow-motion playback of the videorecording, total arytenoidectomy was performed, whic...
Kingston JK, Bayly WM, Meyers KM, Sellon DC, Wardrop KJ.There is evidence that equine platelet reactivity is altered by strenuous exercise. Changes in platelet reactivity could impact haemostasis following exercise-induced injury and may play a role in the pathophysiology of exercise-induced pulmonary haemorrhage. Interpretation of results of previous studies is hindered by potential in vitro-induced changes in platelet activity through the choice of anticoagulant and the use of platelet inhibitors. The present study was undertaken to re-evaluate the effect of exercise on equine platelets using methodologies that minimise in vitro-induced changes i...
Sexton WL, Erickson HH.Cardiopulmonary responses of four ponies were monitored during standard exercise tests (SET), before and after beta-adrenergic receptor blockade with propranolol. The SET consisted of four 5 min increments of increasing speed from 1.0 to 2.8 m/sec on a treadmill at a 7 degrees incline. Data were collected at rest, throughout the SET and recovery. Administration of propranolol to ponies at rest had no effect on cardiopulmonary function. During the SET, increases in heart rate, mean pulmonary artery flow velocity (an index of cardiac output) and right ventricular dP/dt (an index of myocardial co...
Munoz-Nates F, Chateau H, Van Hamme A, Camus M, Pauchard M, Ravary-Plumioen B, Denoix JM, Pourcelot P, Crevier-Denoix N.The repetitive impulsive loading resulting from foot and
ground interaction in the initial part of the stance phase
is often mentioned as a source of risk of developing
subchondral bone damage leading to osteoarthritis, both
in man and horses. Because of the high frequency of this
phenomenon, called the impact shock, accelerometry is
the preferred method to measure it. In the horse, measurement of the hoof ’s vertical deceleration at impact
has been shown to be a useful method for comparing
different track surfaces. However, accelerometric studies
comparing surfaces in trotters at h...
Funkquist P, Wagner PD, Hedenstierna G, Persson SG, Nyman G.In order to evaluate the pulmonary gas exchange during exercise in Standardbred trotters with red cell hypervolaemia (RCHV), 12 horses with RCHV were compared with 9 normovolaemic (NV) horses. VO2 and VCO2 were determined with an open bias flow system. Cardiovascular and haemodynamic data were recorded during exercise at 4 different speeds on a treadmill. Pulmonary gas exchange was assessed by conventional blood gas variables (arterial and mixed venous blood gas tensions), and the ventilation-perfusion distribution VA/Q was estimated by the multiple inert gas elimination technique. VA and AaDO...
Holcombe SJ, Beard WL, Hinchcliff KW, Robertson JT.The effect of transection of the sternothyroideus and sternohyoideus muscles on upper airway mechanics was investigated in exercising horses. Upper airway mechanics of six Standardbred horses were measured at rest and during exercise before and 24 h and 2 wk after sternothyrohyoid myectomy. Transnasal tracheal and pharyngeal catheters connected to differential pressure transducers were used to measure tracheal and pharyngeal pressures. A pneumotachograph mounted on the rostral end of an airtight face mask was used to measure airflow. Horses ran at 50, 75, and 100% of maximal O2 consumption on ...
Geor RJ, McCutcheon LJ, Shen H.The objectives of this study were to determine the effects of 10 consecutive days of moderate-intensity training on 1) the muscular metabolic response to exercise at 100% of the pre-training maximum rate of oxygen consumption (VO2max); and 2) mitochondrial enzyme markers (citrate synthase, CS; succinate dehydrogenase, SDH; 3-hydroxy-acyl-CoA dehydrogenase, HAD) of oxidative capacity in middle gluteal muscle. Six mature, unfit Thoroughbred horses completed both incremental (for determination of VO2max) and high-intensity exercise protocols before (HI1) and after (HI2) training. Training consist...
Manohar M.Regional distribution of diaphragmatic blood flow (Q; 15-microns-diam radionuclide-labeled microspheres) was studied in normal (n = 7) and laryngeal hemiplegic (LH; n = 7) ponies to determine whether the added stress of inspiratory resistive breathing during maximal exercise may cause 1) redistribution of diaphragmatic Q and 2) crural diaphragmatic Q to exceed that in maximally exercising normal ponies. LH-induced augmentation of already high exertional work of breathing resulted in diminished locomotor exercise capacity so that maximal exercise in LH ponies occurred at 25 km/h compared with 3...
Sampson SN, Tucker RL, Bayly WM.We evaluated the relationships of heart score (HS) and echocardiographic measures to maximal oxygen consumption (VO2max), maximal cardiac output (Qmax), and maximal stroke volume (SVmax). Six fit, mature Thoroughbred horses weighing (mean +/- s.e.) 487 +/- 11 kg were run 4 times on an inclined (10%) treadmill. Each run consisted of a 3 min warm-up at 4 m/s followed by completion of an incremental exercise test in which each horse ran until VO2max was reached. Arterial and mixed venous blood was collected to determine arteriovenous oxygen content difference C(a-v)O2[ in the last 15 s of exercis...
Forster HV, Murphy CL, Brice AG, Pan LG, Lowry TF.The major objective was to determine in ponies whether factors in addition to changes in blood PCO2 contribute to changes in plasma [H+] during submaximal exercise. Measurements were made to establish in vivo plasma [H+] at rest and during submaximal exercise, and CO2 titration of blood was completed for both in vitro and acute in vivo conditions. In 19 ponies arterial plasma [H+] was decreased from rest 4.5 neq/l (P less than 0.05) during the 7th min of treadmill running at 6 mph, 5% grade (P less than 0.5). A 5.6-Torr exercise hypocapnia accounted for approximately 2.9 neq/l of this reduced ...
Gehlen H, Bubeck K, Stadler P.In 12 healthy warmblood horses and 10 horses with mitral valve insufficiencies (MVI) of various degrees heart rate and pulmonary artery wedge pressure (PWP) was measured at rest and during standardised exercise on a high speed treadmill. There was a significant increase in PWP with each change in speed of the treadmill (p < 0.01). The PWP of horses with mild mitral valve regurgitation under working conditions was not significantly different compared to the healthy horses. The horses with moderate mitral valve regurgitation showed a significant higher pulmonary artery wedge pressure at rest and...
Bowers J, Slocombe RF.To compare the effect of girth materials and commonly used girth tensions on athletic performance of race-horses and to test the length tension properties of commercially available girths. Methods: Seven horses were exercised at speeds to produce 95% of maximal heart rates on 15 occasions using a randomised block design, and girthed with 5 different girths at 3 nominal tensions of 6, 12 or 18 kg. The girths used were a standard elastic race girth, an 'American' elastic race girth, an elastic race girth twice the normal width, a standard canvas race girth and a canvas race girth at twice the no...
Barrey E, Galloux P, Valette JP, Auvinet B, Wolter R.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 ...
Art T, Lekeux P, Gustin P, Desmecht D, Amory H, Paiva M.The purpose of the present work was to measure the pulmonary inertance (IL) in ponies and to analyze its potential influence on the mechanics of breathing and on their aptitude to increase ventilation during exercise. Five healthy ponies 2.4-4 yr old [mean wt 255 +/- 15 (SE) kg] were used. On the one hand, inertance of the respiratory system (Irs) was computed from the value of the resonant frequency (fr) measured by the forced oscillation technique. On the other hand, respiratory airflow, tidal volume (VT), and transpulmonary pressure (PL) changes were recorded while the ponies were performin...
Art T, Votion D, Lekeux P.The purpose of this study was 1) to measure and compare some physiological parameters in horses during a standardised treadmill exercise performed either in temperate atmospheric conditions (TC) (ambient temperature: 15 degrees C; relative humidity: 55%), or in hot and humid conditions (HHC) (ambient temperature: 30 degrees C; relative humidity: 75%) and 2) to follow the recovery of the same horses during 1 h after both tests. Five healthy fit Standardbred horses were investigated twice at 8 days interval, in TC and in HHC. Some measurements were made during a standardised treadmill exercise t...
Hyyppä S, Saastamoinen M, Reeta Pösö A.Low muscle glycogen at the beginning of exercise may adversely affect performance, increase protein degradation and contribute to the onset of fatigue. As horses are sometimes required to compete on consecutive days both in racing and endurance types of competition, optimal muscle glycogen repletion may improve performance on the day following a race day. The purpose of this experiment was to study the effects of fat supplementation on repletion of muscle glycogen. Twelve Finnhorses performed an exercise test on a treadmill, and 2 and 4 h later they received hay and concentrate (Trial A). Two ...
Whitton RC, Murray RC, Buckley C, Goodship AE, Lekeux P.Training results in marked modelling of the subchondral bone of the carpus, but the effect of training on the subchondral bone of the distal tarsal joints is unknown. The aim of this study was to determine whether training influenced modelling of the third and central tarsal bones in Thoroughbred horses. Twelve untrained Thoroughbred horses were divided into 2 groups. Group 1 underwent a 19 week progressive training regimen on a high speed treadmill. Group 2 were walked for 40 min daily. Images of left tarsi were obtained by magnetic resonance imaging (MRI) with a 0.5 Tesla superconducting mag...
Vervuert I, Coenen M, Wedemeyer U, Chrobok C, Harmeyer J, Sporleder HP.Physical exercise is known to affect calcium homeostasis in horses, but there is little information on the hormonal regulation of calcium metabolism during exercise. In order to evaluate the effects of exercise and training on calcium homeostasis and intact plasma parathyroid hormone, 7 untrained Standardbred horses were studied in a 6 week training programme. These horses were accustomed to running on the treadmill 3 weeks before onset of training and were exercised on a high-speed treadmill with an initial incremental standardised exercise test (SET 1: 6 incremental steps of 5 min duration e...
Siciliano PD, Kawcak CE, McIlwraith CW.Twelve Quarter Horses, 18 to 24 mo of age and having an average body weight of 460+/-12 kg, were randomly assigned to one of two exercise treatments (control and exercise) to study the effect of initiation of exercise training in young horses on vitamin K status. The control treatment consisted of hand-walking the horses 7 min/d and 5 d/wk for 180 d. Exercise consisted of the following treadmill exercise regimen: 2 min at 4.5 to 5.4 m/s, 3 min at 13.4 to 14.3 m/s, and 2 min at 4.5 to 5.4 m/s on 5 d/wk for 180 d. Both groups were allowed free access to brome grass hay (273 mg of phylloquinone/1...
