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.
Rohlf CM, Garcia TC, Fyhrie DP, le Jeune SS, Peterson ML, Stover SM.Mechanical properties of arena surfaces are extrinsic factors for musculoskeletal injury. Vertical impact forces of harrowed and compacted cushion were measured at five locations on 12 arena surfaces (five dirt, seven synthetic [dirt and fiber]). Eight variables related to impact force, displacement, and acceleration were calculated. Surface temperature, cushion depth and moisture content were also measured. The effects of surface material type (dirt/synthetic) and cushion compaction (harrowed/compacted) on vertical impact properties were assessed using an analysis of variance. Relationships o...
Burnley M.The parameters of the hyperbolic speed-duration relationship (the asymptote critical speed, CS, and the curvature constant, D') provide estimates of the maximal steady state speed (CS) and the distance an animal can run, swim, or fly at speeds above CS before it is forced to slow down or stop (D'). The speed-duration relationship has been directly studied in humans, horses, mice and rats. The technical difficulties with treadmill running in dogs and the relatively short greyhound race durations means that, perhaps surprisingly, it has not been assessed in dogs. The endurance capabilities of li...
McCrae P, Spong H, Golestani N, Mahnam A, Bashura Y, Pearson W.Electrocardiograms (ECGs), and associated heart rate (HR) and heart rate variability (HRV) measurements, are essential in assessing equine cardiovascular health and fitness. Smart textiles have gained popularity, but limited validation work has been conducted. Therefore, the objective of this study was to compare HR and HRV data obtained using a smart textile system (Myant) to the gold-standard telemetric device (Televet). Simultaneous ECGs were obtained using both systems in seven horses at rest and during a submaximal exercise test. Bland-Altman tests were used to assess agreement between th...
Adah AS, Ayo JO, Adah DA, Nwonuma CO, Lawal TA.Exercise-induced oxidative stress is a challenge in equine sports. This study aims at determining the effects of ergothioneine on heat shock protein-70 (HSP-70) following the stress of an endurance exercise of 30 km by Arabian stallions. Molecular docking was also done to investigate the interaction between the ligand ergothioneine and heat shock protein-70 using sulfogalactosylceramide and sulfogalactoglycerolipid as standards. The study involved a total of 18 clinically healthy stallions, with an average age of 6.7 ± 2.4 years and an average weight of 411.54 ± 12.46 kg. Only cli...
Cullinane A, Garvey M, Walsh C, Gibbons J, Creighton A.The association between poor performance and respiratory disease in Thoroughbred racehorses that do not have a structural abnormality of the respiratory tract, is often based on anecdotal evidence. The objective of this scoping review was to examine the scientific evidence for such associations. Publications were selected based on a search of three databases (PubMed, Scopus, and CAB Direct), in English and without date restriction, followed by a screening process to exclude non-relevant papers, duplicates, and reviews. This process identified 996 publications of which 20 were analysed using th...
Henry ML, Wesolowski LT, Pagan JD, Simons JL, Valberg SJ, White-Springer SH.Coenzyme Q10 (CoQ10) is an essential component of the mitochondrial electron transfer system and a potent antioxidant. The impact of CoQ10 supplementation on mitochondrial capacities and the muscle proteome is largely unknown. This study determined the effect of CoQ10 supplementation on muscle CoQ10 concentrations, antioxidant balance, the proteome, and mitochondrial respiratory capacities. In a randomized cross-over design, six Thoroughbred horses received 1600 mg/d CoQ10 or no supplement (control) for 30-d periods separated by a 60-d washout. Muscle samples were taken at the end of each peri...
Muhonen S, Julliand V.Racing events challenge the fluid balance of athletic horses. The equine large intestine functions as a fluid reservoir, since the properties of dietary forage fibre affect the digesta water content and the milieu of this ecosystem. This study aimed to investigate the effect of grass maturity and legume forage on the faecal water-holding capacity (WHC) and microbial ecosystem, and the fluid balance and body weight (BW) of French trotters in race training. Six geldings were offered three diets with different fibre compositions: concentrate and late-harvested mature grass haylage (35:65 energy r...
Salz RO, Elliott CRB, Zuffa T, Bennet ED, Ahern BJ.Overstrain of the superficial digital flexor tendon (SDFT) is a common Thoroughbred racehorse limb injury requiring treatment. Objective: To determine whether treatment of SDFT lesions in flat Thoroughbred racehorses with autologous bone marrow-derived mesenchymal stem cells (BM-MSCs) or allogenic adipose-derived mesenchymal stem cells (A-MSCs) is associated with improved likelihood of returning to racing, when compared to racehorses managed with a controlled exercise rehabilitation program (CERP) alone. Methods: Retrospective cohort study combining clinical treatment records with race records...
Wilson J, De Donato M, Appelbaum B, Garcia CT, Peters S.Overtraining syndrome (OTS) is the reduction in performance due to excess training and lack of proper recovery, which can lead to a chronic deprivation of energy and reduction in the repair of damage that can accumulate over time. Here, the effect of acute, intense physical exercise on the expression of innate and adaptive immune genes in 12 racing-bred American Quarter Horses, after resting for 3 days and immediately after intense exercise for 1.8 miles were compared. The expression of 84 genes related to innate and adaptive immune responses was analyzed. Significant variation among individua...
Hammond A, Sage W, Hezzell M, Smith S, Franklin S, Allen K.Heart rate variability (HRV) analysis measures the inter-beat interval variation of successive cardiac cycles. Measurement of these indices has been used to assess cardiac autonomic modulation and for arrhythmia identification in exercising horses. Objective: To report HRV indices during submaximal exercise, strenuous exercise and recovery, and explore relationships with clinical conditions (arrhythmias, lameness, equine gastric ulcer syndrome [EGUS], lower airway inflammation and upper respiratory tract obstructions [URTOs]) in Thoroughbred racehorses. Methods: Retrospective, observational cr...
Ayo JO, Ake AS, Abimbola AA.The study aimed to evaluate effects of packing (load-carrying) and trekking on hematological and biochemical parameters in donkeys during the hot-dry season. Ten pack donkeys, aged 2-3 years, weighing 93 ± 2.7 kg were enrolled in the study and randomly divided into two groups of five animals each. Group 1 donkeys were subjected to packing + trekking while group 2 trekked only. All the donkeys trekked 20 km thrice, 1-day apart. Blood was collected before and after packing or trekking for hematological evaluation; and serum analyzed for electrolyte concentrations, and aspartate aminotransfera...
Kent E, Coleman S, Bruemmer J, Casagrande RR, Levihn C, Romo G, Herkelman K, Hess T.Antioxidant supplementation decreases postexercise oxidative stress but could also decrease muscle protein synthesis. This study compared the effects of three diets: low antioxidant (control, CON), high antioxidant (AO), and branched-chain amino acid high antioxidant (BCAO) supplementation on postexercise protein synthesis and oxidative stress. We hypothesized that supplementing antioxidants with branched-chain amino acids(BCAA) would reduce oxidative stress without hindering muscle protein synthesis. Eighteen mixed-breed polo horses (11 mares and 7 geldings, with age range between 5 and 18 ye...
Waller AP, Lindinger MI.Oral electrolyte supplementation may influence acid-base state during exercise due to the intestinal absorption of administered water and electrolytes used to mitigating sweat losses. This study examined the effect of pre-exercise electrolyte supplementation (3 and 8 L) on plasma acid-base variables at rest, during moderate intensity exercise and during recovery. It was hypothesized that electrolyte supplementation will result in improved acid-base state compared to the alkalosis typical of prolonged exercise. In randomized crossover fashion, four horses were administered 3 L or 8 L of a hypot...
Wang T, Zeng Y, Ma C, Meng J, Wang J, Ren W, Wang C, Yuan X, Yang X, Yao X.In this study, the plasma non-targeted metabolomics of Yili horses were characterized before and after exercise on tracks that differed in surface hardness to better understand exercise-related biochemical changes. Blood samples were obtained from eight trained Yili horses before and immediately after exercise. Samples were used for metabolomic analysis by ultra-performance liquid chromatography-Q-EXACTIVE mass spectrometry. In total, 938 significantly different metabolites involving sugar, lipid, and amino acid metabolism were detected in the plasma, with significant increases in glucose, glu...
Han H, McGivney BA, Allen L, Bai D, Corduff LR, Davaakhuu G, Davaasambuu J, Dorjgotov D, Hall TJ, Hemmings AJ, Holtby AR, Jambal T, Jargalsaikhan B....Selection for system-wide morphological, physiological, and metabolic adaptations has led to extreme athletic phenotypes among geographically diverse horse breeds. Here, we identify genes contributing to exercise adaptation in racehorses by applying genomics approaches for racing performance, an end-point athletic phenotype. Using an integrative genomics strategy to first combine population genomics results with skeletal muscle exercise and training transcriptomic data, followed by whole-genome resequencing of Asian horses, we identify protein-coding variants in genes of interest in galloping ...
Plisak U, Szczepaniak J, Żmigrodzka M, Giercuszkiewicz-Hecold B, Witkowska-Piłaszewicz O.Several anti-inflammatory cytokines have been proposed as markers for exercise monitoring in humans such as the interleukin 1 receptor agonist (IL-ra), or interleukin 13 (IL-13). Equine athletes may be considered a model for human exercise physiology research, however there is a lack of such studies of this species. Thus, we decided to examine the changes of IL-1ra and IL-13 in serum concentration during aerobic (endurance) and anaerobic (race) exercise in horses of different fitness levels in comparison with the well-known anti-inflammatory cytokine interleukin 10 (IL-10). The group of endura...
Macaire C, Hanne-Poujade S, De Azevedo E, Denoix JM, Coudry V, Jacquet S, Bertoni L, Tallaj A, Audigié F, Hatrisse C, Hébert C, Martin P, Marin F....Defining whether a gait asymmetry should be considered as lameness is challenging. Gait analysis systems now provide relatively accurate objective data, but their interpretation remains complex. Thresholds for discriminating between horses that are visually assessed as being lame or sound, as well as thresholds for locating the lame limb with precise sensitivity and specificity are essential for accurate interpretation of asymmetry measures. The goal of this study was to establish the thresholds of asymmetry indices having the best sensitivity and specificity to represent the visual single-lim...
Coelho CS, Silva ASBA, Santos CMR, Santos AMR, Vintem CMBL, Leite AG, Fonseca JMC, Prazeres JMCS, Souza VRC, Siqueira RF, Manso Filho HC, Simões JSA.The purpose of this study was to investigate stressful responses during a 6-week training protocol in young Lusitano horses used for dressage. The hypothesis was that the proposed training protocol would improve fitness and ensure the welfare of the animals by reducing stress predictors. Nine 4-year-old horses were evaluated before (M1) and six weeks after (M2) beginning a training protocol. The training program was performed six times per week and included 40−80 min of individually intensity-adjusted preparatory exercises for dressage. For both moments, the horses were examined before (T0) ...
Elmeua González M, Šarabon N.How the modification of saddle fitting parameters in horse riding affects rider's kinetics is very uncertain. The aim of this study is to describe how manipulating the two main adjustments that an end-user is likely to perform (saddle tilt and stirrup length) affects the biomechanics of a horse rider on a living horse. Eleven showjumpers volunteered to take part in this study. Each participant performed a 120-strides standardization trial at trot and canter, with 0° saddle tilt and stirrup length that would position the rider's knee at 90°. Following the standardization trial, four intervent...
Orr EL, Staniar WB, Smarsh DN.Understanding the frequency, duration, and intensity of exercise is important for determining the optimal diet and management of horses. The objective of the study was to characterize the exercise management of horses in Pennsylvania. An online survey was distributed from February 27th to August 31st, 2020. Respondents were asked to place their horse in an exercise category, as well as report on frequency and duration of exercise and time spent at each gait. Nonparametric statistics (mdn=median) and tests were used when data were not normally distributed. Of the 470 horses, 68% were regularly ...
Heidbuchel A, Van Rossom S, Molenaers N, Minguet P, Jonkers I.In dressage riding, rider posture plays an important role in the performance of the exercises. The purpose of this study was to compare physical fitness and posture on an equestrian simulator between different competitive dressage rider skill levels. Participants (ten expert and twelve novice competitive dressage riders) performed a physiotherapeutic screening test and an equestrian simulator test. The expert rider group (G2) had less variability in both left (P = .002) and right (P = .021) rein force during medium canter on the simulator compared to the novice rider group (G1). The should...
Riders’ asymmetry may cause back pain in both human and equine athletes. This pilot study aimed at documenting in a simple and quick way asymmetry in riders during a simulation of three different riding positions on wooden horseback using load cells applied on the stirrup leathers and identifying possible associations between riders’ asymmetry and their gender, age, level of riding ability, years of riding experience, riding style, motivation of riding, primary discipline and handedness. After completing an interview to obtain the previously mentioned information, 147 riders performed a st...
Lo Feudo CM, Stucchi L, Conturba B, Stancari G, Zucca E, Ferrucci F.Equine Gastric Ulcer Syndrome (EGUS) is a highly prevalent disorder in horses, which can be classified, based on the localization of the lesions, as Equine Squamous Gastric Disease (ESGD) or Equine Glandular Gastric Disease (EGGD). Although EGUS is recognized as a common cause of poor performance in racehorses, objective investigations about its relation with athletic capacity are lacking. Therefore, the present retrospective study aims to evaluate the associations between EGUS severity and some fitness parameters measured during an incremental treadmill test in Standardbred racehorses in trai...
McCrae P, Spong H, Rutherford AA, Osborne V, Mahnam A, Pearson W.Electrocardiography (ECG) is an essential tool in assessing equine health and fitness. However, standard ECG devices are expensive and rely on the use of adhesive electrodes, which may become detached and are associated with reduced ECG quality over time. Smart textile electrodes composed of stainless-steel fibers have previously been shown to be a suitable alternative in horses at rest and during exercise. The objective of this study was to compare ECG quality using a smart textile girth band knit with silver and carbon yarns to standard adhesive silver/silver chloride (Ag/AgCl) electrodes. S...
Martins JN, Silva SR.Equitation is a cause of physiological stress in the equine athlete, and personality is a factor generally associated with the different responses of equines to stressors. This study explored ocular temperature, measured via infrared thermography, associated with personality and stress in horses submitted to dressage exercising in riding lessons, ridden training and lunging. Infrared thermograms of 16 horses were taken before and after sessions using an FLIR F4 camera (FLIR Systems AB, Sweden) to determine maximum eye surface IRT temperature (IRTmax), and total training time was registered (T)...
Kapteijn CM, Frippiat T, van Beckhoven C, van Lith HA, Endenburg N, Vermetten E, Rodenburg TB.Measuring physiological parameters of stress in horses during groundwork, for example when involved in equine-assisted interventions, is important to gain insight into the stress levels of the horses. Heart rate and heart rate variability can be used as physiological indicators of stress in horses. Heart rate monitors could be easily incorporated into practice, as they are not expensive and easy to use. However, it is questionable whether heart rate monitors present accurate heart rate variability results in exercising horses, similar to electrocardiograms. The aim of this study was to determi...
Mild-moderate equine asthma (MEA) is a common respiratory disorder among racehorses, characterized by lower airway inflammation. Although it is generally agreed that MEA causes poor performance, contrasting results have been reported about the effects of tracheal mucus and the leukocyte populations of the bronchoalveolar lavage (BAL) on performance. This study aims to investigate the associations between airway inflammation and fitness parameters measured during an incremental treadmill test on Standardbred racehorses. For this purpose, the clinical records of 116 Standardbreds subjected to a ...
Gmel AI, Haraldsdóttir EH, Bragança FMS, Cruz AM, Neuditschko M, Weishaupt MA.In gait quality assessments of horses, stride length (SL) is visually associated with spectacular movements of the front limbs, and described as ground coverage, while the movement of the hind limb under the body is supposedly essential to a longer over-tracking distance (OTD). To identify movement patterns with strong associations to SL and OTD, limb and body kinematics of 24 Franches-Montagnes (FM) stallions were measured with 3D optical motion capture (OMC) on a treadmill during an incremental speed test at trot (3.3-6.5 m/s). These measurements were correlated to the scores of ground cover...
Saitua A, Castejón-Riber C, Requena F, Argüelles D, Calle-González N, de Medina AS, Muñoz A.During a water treadmill (WT) exercise, horses change their accelerometric patterns. We aimed to analyze if these changes persist during terrestrial locomotion. Six horses were randomly subjected to 40 min duration WT exercises, without water (WW), at the depth of fetlock (FET), carpus (CAR) and stifle (STF), with a day off between them. Before and after 30 min after WT, horses were evaluated at walk and at trot on a track with a triaxial accelerometer fixed on the pectoral (PECT) and sacrum (SML) regions. The percent of change from baseline (before WT and after each exercise session) were cal...
Legg KA, Cochrane DJ, Gee EK, Macdermid PW, Rogers CW.To enhance performance in race riding, knowledge of current training workload is required. The objectives of this study were to quantify the physiological demands and profile the muscle activity of jockeys riding track-work. Methods: Ten apprentice jockeys and 48 horses were instrumented with heart-rate monitors, accelerometers, and a surface electromyography BodySuit (recording 8 muscle groups: quadriceps, hamstrings, gluteal, lower back, obliques, abdominal, trapezial, and pectoral) that recorded continuously while riding their normal morning track-work. Data were extracted and time matched ...
Mach N, Moroldo M, Rau A, Lecardonnel J, Le Moyec L, Robert C, Barrey E.Endurance exercise has a dramatic impact on the functionality of mitochondria and on the composition of the intestinal microbiome, but the mechanisms regulating the crosstalk between these two components are still largely unknown. Here, we sampled 20 elite horses before and after an endurance race and used blood transcriptome, blood metabolome and fecal microbiome to describe the gut-mitochondria crosstalk. A subset of mitochondria-related differentially expressed genes involved in pathways such as energy metabolism, oxidative stress and inflammation was discovered and then shown to be associa...
Clayton HM, Hobbs SJ.Gaits are typically classified as walking or running based on kinematics, the shape of the vertical ground reaction force (GRF) curve, and the use of inverted pendulum or spring-mass mechanics during the stance phase. The objectives of this review were to describe the biomechanical characteristics that differentiate walking and running gaits, then apply these criteria to classify and compare the enhanced natural gait of collected trot with the artificial gaits of passage and piaffe as performed by highly trained dressage horses. Limb contact and lift off times were used to determine contact se...
Popel AS, Johnson PC, Kameneva MV, Wild MA.The purpose of this study was to show that two rheological parameters, red blood cell (RBC) sedimentation rate and apparent blood viscosity at low shear rate, characterizing the degree of RBC aggregation, correlate significantly with the maximal mass-specific rate of oxygen consumption or aerobic capacity (VO2max). Comparisons were made within two groups of similarly sized athletic and sedentary species: group 1, pronghorn antelope, dog, goat, and sheep; and group 2, horse and cow. The pronghorn antelope (Antilocapra americana) is one of the most athletic mammals, and we have obtained data on ...
Young LE, Rogers K, Wood JL.Cardiac murmurs associated with valvular regurgitation occur commonly in conditioned performance horses, but their association with athletic performance is unknown. Objective: Cardiac valvular regurgitation has a negative association with race performance. Methods: Five hundred and twenty-six "race fit" Thoroughbred racehorses engaged in either flat (race distance 1,000-2,500 m) or jump racing (race distance 3,200-6,400 m). Methods: Cardiac auscultation and color flow Doppler (CFD) echocardiography were performed on 777 occasions. The associations between the presence and severity of either an...
Capomaccio S, Cappelli K, Spinsanti G, Mencarelli M, Muscettola M, Felicetti M, Verini Supplizi A, Bonifazi M.Horses and humans share a natural proclivity for athletic performance. In this respect, horses can be considered a reference species in studies designed to optimize physical training and disease prevention. In both species, interleukin-6 (IL-6) plays a major role in regulating the inflammatory process induced during exercise as part of an integrated metabolic regulatory network. The aim of this study was to compare IL-6 and IL-6 receptor (IL-6R) mRNA expression in peripheral blood mononuclear cells (PBMCs) in trained and untrained humans and horses. Results: Nine highly trained male swimmers (...
Brkljača Bottegaro N, Gotić J, Šuran J, Brozić D, Klobučar K, Bojanić K, Vrbanac Z.Oxidative stress (OS) associated with an intense exercise may have a negative influence on equine health. The aim of this study was to determine the effects of endurance races on oxidative and antioxidative status of horses by evaluating changes in reactive oxygen metabolites (d-ROMs), malondialdehyde (MDA), biological antioxidant potential (BAP) and oxidative stress index (OSI) values. The study was carried out on 53 race starts (28 individual horses) competing at different endurance races according to distance (40 and 80 km) and difficulty (easy and demanding). Blood samples were taken befo...
Morgan RA, Keen JA, McGowan CM.Treatment of equine metabolic syndrome (EMS) is essential to improve insulin sensitivity and reduce the risk of laminitis. Calorie restriction and increased exercise are the mainstays of treatment but there is potential for poor owner compliance. Objective: To determine whether significant weight loss accompanied by improvements in measures of insulin sensitivity can be achieved in horses and ponies with EMS managed by their owners in their normal environment under veterinary guidance. Methods: Retrospective clinical case series. Methods: Horses and ponies attending 2 university hospitals for ...
Franklin SH, Van Erck-Westergren E, Bayly WM.Horses are elite athletes when compared with other mammalian species. In the latter, performance is limited by cardiovascular or musculoskeletal performance whereas in athletic horses it is the respiratory system that appears to be rate limiting and virtually all horses exercising at high intensities become hypoxaemic and hypercapnoeic. This is due to both diffusion limitation and a level of ventilation inadequate for the metabolic level that enables horses to exercise at these intensities. In conjunction with these blood gas changes, total pulmonary resistance increases and the work of breath...
Richard EA, Fortier GD, Pitel PH, Dupuis MC, Valette JP, Art T, Denoix JM, Lekeux PM, Erck EV.The objectives of this study were to determine the prevalence of sub-clinical diseases in poorly-performing Standardbred horses, compare their physiological response to exercise with control horses, and identify predictive parameters of poor-performance. Fifty horses underwent thorough clinical and ancillary examinations, including haematological and biochemical evaluation, Doppler echocardiography, standardised exercise tests (SETs) on both treadmill and racetrack, treadmill video-endoscopy and collection of respiratory fluids. Most of the poorly-performing horses exhibited many concomitant d...
Ohmura H, Jones JH.We investigated changes in heart rate (HR) and HR variability as a function of age in newborn foals to old Thoroughbred horses. Experiments were performed on a total of 83 healthy and clinically normal Thoroughbred horses. Resting HR decreased with age from birth. The relationship between age and HR fit the equation Y=48.2X(R=0.705); the relationship between age and HR for horses 0-7 years old fit the equation Y=44.1X(R=0.882). Seven-day-old horses had the highest HR values (106 ± 10.3 beat/min). The low frequency (LF) and high frequency (HF) powers increased with age in newborn to old horses...
Robert C, Valette JP, Denoix JM.Electromyographic activity (EMG) was used to determine how hindlimb muscle activation patterns vary with speed and incline in the horse. EMG was recorded using surface electrodes over the gluteus medius and tensor fasciae latae muscles during treadmill locomotion at trot for different combinations of speed (3.5 to 6 m/s) and inclination (0, 3 and 6%). Raw EMG signals were processed to determine stride duration, activity onset and end, and integrated EMG (IEMG). Stride and stance phase duration decreased linearly with increasing speed. Stride duration was not influenced by the slope. Onset and ...
Ferlazzo A, Cravana C, Fazio E, Medica P.The review discusses the hormonal changes during exercise stress. The exercise generally produces a rise of adrenaline (A), noradrenaline (NA), adrenocorticotropic hormone (ACTH), cortisol, glucagon, growth hormone, arginine vasopressine, etc., and a drop of insulin. The hormonal events during reestablishment of homeostasis due to exercise stress can be divided into a catabolic phase, with decreased tolerance of effort, and reversible biochemical, hormonal and immunological changes, and an anabolic phase, with a higher adaptive capacity, and enhanced performance. The two main hormonal axes act...
Valberg SJ.Optimal function of skeletal muscle is essential for successful athletic performance. Even minor derangements in locomotor muscle function will impact power output, coordination, stamina, and desire to work during exercise. In this review, the presenting clinical signs, differential diagnoses, approach to diagnostic testing and treatment of muscle atrophy and weakness, focal muscle strain, and exertional myopathies are discussed. Exertional myopathies include polysaccharide storage myopathies, recurrent exertional rhabdomyolysis, malignant hyperthermia, and myofibrillar myopathy.
Holmström M, Fredricson I, Drevemo S.The trotting gait of 4 approved Swedish Warmblood stallions with a mean gait score > or = 8.67 (maximum score = 10) at official performance tests was recorded by high speed film (approximately 250 frames/sec). Angular patterns and hoof trajectories of the left fore and hind limbs were analysed, and presented as mean and standard deviation curves. The horses had a mean stride duration of 794.0 msec (sd 13.7) and the mean diagonal advanced placement was +29.8 msec (sd 7.6). The variation in angular patterns between the horses was greatest during the swing phase. The trajectory of the hind hoof r...
Arfuso F, Giudice E, Panzera M, Rizzo M, Fazio F, Piccione G, Giannetto C.The monitoring of endocrine and immunologic markers during exercise is of paramount importance to assess and/or maintain the physical well-being of athletes as well as to optimize the athletic performance. This study aimed to investigate the linkage between acute stress response and immune status in Thoroughbred horses competing in an official 1300-m race. From 10 horses blood was collected 1 week before the day of the race (1W-BEFORE), before (REST) and immediately after the race to assess the cortisol, Interleukin-1 receptor antagonist (IL-1Ra), total proteins, white blood cells (WBC), red b...
Setterbo JJ, Garcia TC, Campbell IP, Reese JL, Morgan JM, Kim SY, Hubbard M, Stover SM.To compare hoof acceleration and ground reaction force (GRF) data among dirt, synthetic, and turf surfaces in Thoroughbred racehorses. Methods: 3 healthy Thoroughbred racehorses. Methods: Forelimb hoof accelerations and GRFs were measured with an accelerometer and a dynamometric horseshoe during trot and canter on dirt, synthetic, and turf track surfaces at a racecourse. Maxima, minima, temporal components, and a measure of vibration were extracted from the data. Acceleration and GRF variables were compared statistically among surfaces. Results: The synthetic surface often had the lowest peak ...
Buhl R, Ersbøll AK.To assess whether physical training induces cardiac hypertrophy and valvular regurgitation in maturing Standardbred trotters and to establish a prediction model for the size of the left ventricle. Methods: Longitudinal observational study. Methods: 53 Standardbred trotters. Methods: Each horse underwent 2-D, M-mode, and color flow Doppler echocardiography at 5.5 years of age; previously, each horse had been examined at 2, 2.5, 3, and 3.5 (time of maturity) years of age. Horses were or were not in training or racing for variable periods during the entire assessment period; data for a given hors...
Robert C, Valette JP, Denoix JM.The purpose of this study was to evaluate the effects of speed and slope on the activity of trunk muscles. The electromyographic (EMG) activity of the splenius (Sp), longissimus dorsi (LD) and rectus abdominis (RA) muscles was recorded with surface electrodes during treadmill locomotion at trot for different combinations of speed (3.5 to 6 m/s) and slope (0 to 6%). Raw EMG signals were processed to determine activity duration, onset and end and integrated EMG (IEMG). For the 3 muscles investigated, onset and end of activity were obtained earlier in the stride cycle when speed increased. A long...
Biknevicius AR, Mullineaux DR, Clayton HM.Gaited horses employ 4-beat stepping (singlefoot) gaits that extend into speeds typical of trots. Ground reaction force (GRF) patterns of these specialised gaits have not been reported; therefore, appraisal of these gaits using nongaited horse kinetics may lead to clinical misjudgements. Objective: GRFs of tölting Icelandic horses will be comparable in profile and magnitude with those of trotting horses. Methods: Forelimb and hindlimb GRFs were obtained for 10 Icelandic horses ridden at a tölt. These data were evaluated across 3 speed ranges: <2, 2.5-5 and >5 m/sec. Results: Virtually all ve...
Evans DL, Rose RJ.Cardiovascular and respiratory responses to submaximal exercise training were investigated in 6 thoroughbred racehorses. Oxygen uptake, heart rate (HR) and arteriovenous oxygen content difference were measured during incremental treadmill exercise tests, before and after 7 weeks of treadmill training. Cardiac output during exercise was calculated by the direct Fick technique. Maximal oxygen uptake (VO2max) was increased by 23% after training, from 129.7 ml/kg/min to 160.0 ml/kg/min. The treadmill speed at which VO2max was attained increased by 19%. The increased aerobic power after training wa...
de Graaf-Roelfsema E, Keizer HA, van Breda E, Wijnberg ID, van der Kolk JH.Overtraining is an imbalance between training and recovery leading to symptoms associated with a neuroendocrine dysbalance called the overtraining syndrome, a disease characterized by behavioral, emotional and physical symptoms similar with depression. Although the prevalence of overtraining is high in human and equine athletes, at present no sensitive and specific test is available to prevent or diagnose overtraining. Nowadays, it is believed that combination of different (hormonal) parameters appear to be the best indicators of overtraining. Therefore, this review provides a summary of previ...
Nolen-Walston RD, Harris M, Agnew ME, Martin BB, Reef VB, Boston RC, Davidson EJ.To determine whether there are important differences relating to seasonality of signs or clinical features between subtypes of inflammatory airway disease (IAD) in horses caused by neutrophilic and eosinophilic-mastocytic inflammation having dissimilar etiopathologic pathways. Methods: Retrospective case series. Methods: 98 horses. Methods: Data were compiled from medical records of horses examined because of poor performance from 2004 through 2010. Horses underwent a standardized high-speed treadmill test, lameness evaluation, cardiac evaluation, and postexercise bronchoalveolar lavage (BAL)....
Tan RH, Dowling BA, Dart AJ.The purpose of the study was to describe the prevalence of upper airway abnormalities and establish if any significant associations existed between study variables and the two most frequently identified disorders; axial deviation of the aryepiglottic folds and dorsal displacement of the soft palate. The clinical records and video-recordings of all horses referred for upper respiratory tract evaluation during high-speed treadmill videoendoscopy between November 1997 and September 2003 were reviewed. Of 291 horses included in the study, 265 underwent resting endoscopy and 42% (112/265) had a rec...
Takahashi Y, Ohmura H, Mukai K, Shiose T, Takahashi T.Horses need aggressive cooling to prevent exertional heat illness after strenuous exercise in hot and humid conditions. This study compared various methods for cooling horses in such conditions, testing the hypothesis that continual application of running water would be the most effective method to decrease core temperature. Five Thoroughbreds were exercised on a treadmill at wet-bulb globe temperature of 31.8 ± 0.1°C until their pulmonary artery temperature reached 42°C. The time until the pulmonary artery temperature returned to <39°C (t) and the rectal temperature at 30 minutes afte...
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...
Robert C, Valette JP, Degueurce C, Denoix JM.The purpose of this study was to demonstrate the feasibility of surface electromyography in the horse and to correlate electromyographic activity with kinematic data. Surface electromyography of seven hindlimb muscles was recorded in five horses at trot on a treadmill. Simultaneously, kinematic analysis of the hindlimb was performed using a three-dimensional system and a unidirectional accelerometer was attached to the hoof. Electromyographic activities of the gluteus medius, vastus lateralis and two parts of the biceps femoris started in the late part of the swing phase and ended in the late ...
Almeida ML, Feringer WH, Carvalho JR, Rodrigues IM, Jordão LR, Fonseca MG, Carneiro de Rezende AS, de Queiroz Neto A, Weese JS, Costa MC, Lemos EG....Recent studies performed in humans and rats have reported that exercise can alter the intestinal microbiota. Athletic horses perform intense exercise regularly, but studies characterizing horse microbiome during aerobic conditioning programs are still limited. Evidence has indicated that this microbial community is involved in the metabolic homeostasis of the host. Research on ergogenic substances using new sequencing technologies have been limited to the intestinal microbiota and there is a considerable demand for scientific studies that verify the effectiveness of these supplements in horses...
Tsubone H, Hanafusa M, Endo M, Manabe N, Hiraga A, Ohmura H, Aida H.The present study aimed to clarify changes of oxidative stress and antioxidative functions in treadmill-exercised Thoroughbred horses (n=5, 3 to 7 years old), using recently developed techniques for measurement of serum d-ROMs for oxidative stress, and BAP for antioxidative markers. Also, the effect of nasogastric administration of hydrogen-rich water (HW) or placebo water preceding the treadmill exercise on these parameters was examined. Each horse was subjected to a maximum level of treadmill exercise in which the horses were exhausted at an average speed of 13.2 ± 0.84 m/sec. Blood samples...
Smiet E, Van Dierendonck MC, Sleutjens J, Menheere PP, van Breda E, de Boer D, Back W, Wijnberg ID, van der Kolk JH.Different head-and-neck positions (HNPs) are discussed in relation to potential welfare issues. To evaluate the effect on welfare, seven Royal Dutch Sport horses were studied in five predetermined HNPs: (1) unrestrained (HNP1); (2) neck raised, bridge of nose around the vertical (HNP2); (3) neck lowered and considerably flexed, bridge of nose pointing towards the chest (HNP4); (4) neck raised and extended, bridge of nose in front of the vertical (HNP5), and (5) neck lowered and flexed, bridge of nose pointing towards the carpus (HNP7). A standardised exercise test (SET) of 34 min consisted o...
Witkowska-Piłaszewicz O, Bąska P, Czopowicz M, Żmigrodzka M, Szarska E, Szczepaniak J, Nowak Z, Winnicka A, Cywińska A.Development of an anti-inflammatory state during physical training has been postulated in both human and equine athletes, but it is not completely understood. The aim of this study was to investigate whether endurance training changes pro- and anti-inflammatory cytokine profiles within a 20-week training season in young inexperienced endurance horses. Nine Arabian horses were examined in this prospective 20-week follow-up study. Blood samples were analysed 5 times monthly, at rest and after training sessions. Routine haematological examinations were performed. Cytokine patterns including IL-1...
