Endurance in horses refers to the ability of these animals to sustain prolonged physical activity, often assessed in the context of endurance racing or long-distance riding. This capability is influenced by a combination of physiological, genetic, and environmental factors. Key aspects of equine endurance include cardiovascular efficiency, muscular stamina, and metabolic adaptations that allow for sustained energy production. Research in this area often focuses on the mechanisms of energy metabolism, the impact of training regimens, and the genetic markers associated with endurance performance. This page compiles peer-reviewed research studies and scholarly articles that explore the physiological, genetic, and environmental determinants of endurance in horses.
van der Kolk JH, Thomas S, Mach N, Ramseyer A, Burger D, Gerber V, Nuoffer JM.Mitochondrial β-oxidation is essential in fat metabolism and can be monitored with blood acylcarnitine profiling, as partly degraded fatty acids accumulate as their carnitine esters. To guarantee continuous energy supply during long-distance exercise, endurance horses oxidise considerable amounts of fat in the mitochondrion. In endurance races over 80 km, glycogen depletion is evident in equine slow-twitch high oxidative muscle fibres and as a consequence, horses participating in endurance races over 80 km rely almost entirely on β-oxidation of fatty acids. This study investigated mitoch...
Zavistanaviciute P, Poskiene I, Lele V, Antanaitis R, Kantautaite J, Bartkiene E.The aim of this study was to evaluate the influence of the newly isolated Lactobacillus plantarum LUHS135 and Lactobacillus paracasei LUHS244 strains grown in potato juice (with a cell count of 8.0-9.0 log10 CFU/ml) on the blood and faeces parameters of exercising horses. The horses were classified into four different groups: a control group (which received no probiotics); the first group (which received 200 ml of L. plantarum culture in potato juice); the second group (which received 200 ml of L. paracasei culture in potato juice); and the third group (which received an L. plantarum and L. pa...
Schambourg M, Taylor PM.Alteration of limb sensitivity is forbidden in equine sports but difficult to enforce. We aimed to develop an objective field method to assess mechanical nociceptive threshold (MNT) in endurance horses. Methods: A remotely controlled pneumatic actuator (1 mm tip) was used to measure forelimb pastern MNT in 108 endurance horses. Results: Median (IQR) MNT at rest was 1.9 N (0.9-3.5). Icing had no significant effect on limb sensitivity. MNT measured at weekly intervals increased from week 1 (1.2 N (0.6-1.8)) to week 3 (1.9 N (1.2-2.8)) (P<0.05). In 17 horses without impaired sensitivity, MNT ...
Tarancón I, Armengou L, Melendez-Lazo A, Pastor J, Ríos J, Jose-Cunilleras E.To assess the prevalence of exercise-induced pulmonary hemorrhage (EIPH) among elite endurance horses after competition in a long-distance race. 20 endurance horses and 12 nonexercised or minimally exercised age-, breed-, and trainer-matched horses from the same environment (control horses). Bronchoalveolar lavage fluid samples collected from endurance horses at 3 to 8 days (sample A) and 36 to 38 days (sample B) after the race (100 km in 1 day [n = 3], 70 km/d for 2 days [12], or 100 km/d for 2 days [5]) were cytologically examined for the presence of hemosiderophages. Samples from control ho...
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...
Legg KA, Weston JF, Gee EK, Bolwell CF, Bridges JP, Rogers CW.The welfare of horses in endurance competitions has been the focus of recent media attention. Epidemiological studies have examined the sport at the international (FEI) level. However, much of the participation in the sport occurs at a national level in preparation for FEI level competition. The aims of this study were to describe participation in, and risk factors for elimination, from New Zealand endurance competitions. Data were collated from all endurance competitions (≥40 km) held in New Zealand during the 2010/11-2015/16 competition seasons. There were 6885 starts (n = 775 horses, n = ...
Musiał AD, Ropka-Molik K, Piórkowska K, Jaworska J, Stefaniuk-Szmukier M.In horses, the identification of the genetic background of phenotypic variation, especially with regard to performance characteristics and predisposition to effort, has been extensively studied. As α-actinin-3 function is related to the regulation of muscle contraction and cell metabolism, the ACTN3 gene is considered one of the main genetic factors determining muscle strength. The aim of the present study was to assess the genotype distribution of two SNP variants within the equine ACTN3 gene (g.1104G > A and c.2334C > T) across different utility types and horse breeds. The ana...
Bennet ED, Parkin TDH.Endurance riding competitions are increasingly popular, with a corresponding awareness of the frequency of Failure to Qualify (FTQ) due to lameness or metabolic problems. Fédération Equestre Internationale (FEI) rules require a minimum number of days between competitions, known as a mandatory rest period (MRP). Objective: To analyse the impact on FTQ outcomes of MRPs which applied between January 2014 and December 2016, and model potential changes to MRPs to establish which rule change could lead to the largest further reduction in the number of FTQ outcomes. Methods: Retrospective cohort st...
Windberger U, Auer R, Seltenhammer M, Mach G, Skidmore JA.From a certain level of exercise-intensity onward, hematocrit increases in horses, which brings more oxygen carriers into the bloodstream. Camels, however, when used in competitive racing could be even in need of iron supplementation and blood transfusions due to a severe reduction of their available hematocrit compared to their resting hematocrit. Since the extrinsic and intrinsic mechanical properties of camel erythrocytes (RBC) are so different compared to RBCs of other mammals, the question arises whether this observation might be a response to endurance exercise aiming at keeping the RBC ...
Di Battista C, Conte M, Pepe M, Petrizzi L, Beccati F.There is limited information on risk factors for elimination from endurance rides and changes over the years. The objectives of this study were to describe elimination for irregular gait and metabolic reasons from Fédération Equestre Internationale (FEI) endurance rides in Italy (2004-2015) and to assess risk factors and to investigate changes in elimination rates and speed over the long term. Data for FEI endurance rides were collected from three websites. Year, month, day, location, class (Concours de Raid d'Endurance International [CEI]*/**/***), restriction to young riders, distance (km)...
Muñoz A, Castejón-Riber C, Castejón F, Rubio DM, Riber C.Simulated hypoxic normobaric devices have been used in human beings in order to enhance endurance capacity. These devices are sealed chambers where the athletes are supposed to stay for at least 6-8 hr daily. The current research assesses the changes in time-domain, spectral and non-geometrical heart rate variability (HRV) parameters in 6 horses subjected to progressive duration periods inside of a hermetically sealed chamber. It was pursued, firstly to evaluate the intensity of the stress experienced by the animals and secondly to elucidate whether the horses might require an acclimation per...
Plancade S, Clark A, Philippe C, Helbling JC, Moisan MP, Esquerré D, Le Moyec L, Robert C, Barrey E, Mach N.An integrated analysis of gut microbiota, blood biochemical and metabolome in 52 endurance horses was performed. Clustering by gut microbiota revealed the existence of two communities mainly driven by diet as host properties showed little effect. Community 1 presented lower richness and diversity, but higher dominance and rarity of species, including some pathobionts. Moreover, its microbiota composition was tightly linked to host blood metabolites related to lipid metabolism and glycolysis at basal time. Despite the lower fiber intake, community type 1 appeared more specialized to produce ace...
Le Moyec L, Robert C, Triba MN, Bouchemal N, Mach N, Rivière J, Zalachas-Rebours E, Barrey E.Endurance racing places high demands on energy metabolism pathways. Metabolomics can be used to investigate biochemical responses to endurance exercise in humans, laboratory animals, and horses. Although endurance horses have previously been assessed in the field (i.e., during races) using broad-window Nuclear Magnetic Resonance metabolomics, these studies included several different race locations, race distances, age classes, and race statuses (finisher or elimination). The present NMR metabolomics study focused on 40 endurance horses racing in three race categories over 90, 120, or 160 km. T...
Witkowska-Piłaszewicz O, Bąska P, Czopowicz M, Żmigrodzka M, Szczepaniak J, Szarska E, Winnicka A, Cywińska A.Sport training leads to adaptation to physical effort that is reflected by the changes in blood parameters. In equine endurance athletes, blood testing is accepted as a support in training, however, only the changes before versus after exercise in creatine phosphokinase activity (CPK) and basic blood parameters are usually measured. This study is the first longitudinal investigation of the changes in routinely measured blood parameters and, additionally, serum amyloid A (SAA), during seven months, in Arabian horses introduced to endurance training and competing in events for young horses. It h...
Page AE, Stewart JC, Fielding CL, Horohov DW.Previous work to evaluate various risk factors for failure to complete competitive endurance rides has examined clinicopathologic parameters, measurements of inflammation, and speed. Here, inflammatory markers were measured before, during, and after a long-distance, competitive endurance ride to examine the intraride dynamics of inflammatory marker expression and attempt to correlate those findings with whether a horse completed or failed to complete the ride. A total of 77 horses entered into the 2018 Tevis Cup Ride in California were enrolled in the study. Peripheral blood samples for mRNA i...
Rajão MD, Leite CS, Nogueira K, Godoy RF, Lima EMM.The aim of this study was to understand the bone response against the exercise adaptations to reduce the occurrence of orthopedic injuries in endurance horses. To this end, the objective of the present work was to investigate how the bone adaptation on adult equines that were trained for 4-5 yr to endurance races responds to the long-term exercise of moderate intensity by comparing to non-athlete horses. For this purpose, 14 Arabian horses were selected and divided equally into two groups; a control group formed by animals that had never practiced physical activity nor been tamed and an exerci...
Redaelli V, Luzi F, Mazzola S, Bariffi GD, Zappaterra M, Nanni Costa L, Padalino B.The aim of this pilot study was to document the effects of endurance training at different intensities on heart rate (HR), blood count, serum cortisol, and maximal temperatures of different body locations, namely eye, crown, pastern pasterns, and muscle (, measured by infrared thermography technique (IRT) in horses trained for endurance. Possible associations among the studied parameters were also investigated. Our hypothesis was that temperature, measured by IRT after endurance training of different intensities would vary depending on the intensity and would be positively correlated with HR...
Cavalcanti RTC, Teixeira PAC, Levy RS, Pereira HMG, Aquino Neto FR.Erythropoiesis-stimulating agents (ESAs) have been used in horses for doping purposes to increase the performance of these animals in endurance sports. Currently, enzyme-linked immunosorbent assay (ELISA) and mass spectrometry methods are used to detect ESA abuse in equines. However, the sarcosyl polyacrylamide gel-electrophoresis (SAR-PAGE) technique could also be used, since its application in human doping control is well established and has proven to be more sensitive. In this work, the SAR-PAGE method was used to detect recombinant human erythropoietin (rHuEPO), novel erythropoiesis stimul...
Lorello O, Ramseyer A, Burger D, Gerber V, Navas de Solis C.The objectives of this study were to describe the changes in clinical cardiovascular examination variables over a competition season in groups of competitive eventing and endurance horses and to compare these findings to non-competitive controls of the same breeds. Methods: This study included two eventing horses, 11 endurance horses, and 13 eventing and seven endurance control breed-matched horses. Methods: Cardiovascular examinations were performed before starting the competition season, in the middle and at the peak/end of the competition season. Examinations included auscultation of the he...
Cozzi MC, Strillacci MG, Valiati P, Rogliano E, Bagnato A, Longeri M.The Akhal-Teke horse (AKH) is native of the modern Turkmenistan area. It was introduced in Italy from 1991 to 2000 mainly as an endurance horse. This paper characterizes the genetic variability of the whole Italian AKH horse population and evaluates their inbreeding level by analyzing microsatellite markers and mitochondrial D-Loop sequences. Methods: Seventeen microsatellite marker loci were genotyped on 95 DNA samples from almost all the AKH horses bred in Italy in the last 20 years. Standard genetic variability measures (Ho, He, FIS) were compared against the same variables published on oth...
Izzati MRNZ, Noraniza MA, Adamu L, Rasedee A.Endurance horses are usually eliminated from the race due to lameness, metabolic ailments or technical reasons. The purpose of the study was to determine the validity and reliability of the metabolic disorder index (MDI) in predicting metabolic eliminations in endurance horses during an endurance race. Fifty-four endurance horses competing on two local endurance tracks were involved in the study. Blood samples were collected a day prior to the event to determine packed cell volume (PCV), chloride (Cl), interleukin-6 (IL-6), creatine kinase (CK) and glutathione reductase (GR) concentrations fro...
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...
Sauer FJ, Bruckmaier RM, Ramseyer A, Vidondo B, Scheidegger MD, Gerber V.The aims of this study were to better characterize the adrenal response to i.v. adrenocorticotropic hormone (ACTH) in horses with and without gastric disease and to validate and simplify the ACTH stimulation test by determining the diagnostic accuracy of six consecutive sampling time points after ACTH administration for equine glandular gastric disease (EGGD) and equine squamous gastric disease (ESGD). Twenty-six endurance and eventing horses without clinical disease [Sport Horse Population (SHP)] and an independent population of 62 horses [General Population (GP)] were grouped by gastroscopic...
López-Correa RD, Peñagaricano F, Rovere G, Urioste JI.The aim of this study was to estimate the genetic parameters of performance in a 750-km, 15-day ride in Criollo horses. Heritability (h2 ) and maternal lineage effects (mt2 ) were obtained for rank, a relative placing measure of performance. Additive genetic and maternal lineage (rmt) correlations among five medium-to-high intensity phase ranks (pRK) and final rank (RK) were also estimated. Individual records from 1,236 Criollo horses from 1979 to 2012 were used. A multivariate threshold animal model was applied to the pRK and RK. Heritability was moderate to low (0.156-0.275). Estimates of mt...
Cappelli K, Capomaccio S, Viglino A, Silvestrelli M, Beccati F, Moscati L, Chiaradia E.Endurance exercise induces metabolic adaptations and has recently been reported associated with the modulation of a particular class of small noncoding RNAs, microRNAs, that act as post-transcriptional regulators of gene expression. Released into body fluids, they termed circulating miRNAs, and they have been recognized as more effective and accurate biomarkers than classical serum markers. This study examined serum profile of miRNAs through massive parallel sequencing in response to prolonged endurance exercise in samples obtained from four competitive Arabian horses before and 2 h after the ...
Bennet ED, Parkin TDH.An epidemiological study of elite endurance riding was conducted using data from every Fédération Equestre Internationale (FEI) endurance event from 2010 to 2015, comprising 82,917 starts. The aim of the study was to identify risk factors associated with failure to qualify outcomes for horses during FEI endurance rides. The FEI endurance rules state that, during a ride, horses must be assessed by veterinarians several times, giving veterinarians the opportunity to prevent those horses exhibiting signs of lameness or metabolic problems from continuing further. Multivariable logistic regressio...
Bennet ED, Parkin TDH.This study examined the association between riding speed and elimination in Fédération Equestre Internationale (FEI) endurance events. A total of 35,061 horse starts from 1st July 2012 to 31st December 2015 were included in a multivariable logistic regression model containing 25 different risk factors. Riding speeds in individual stages ('loops') were included as individual risk factors in studying the progress of horses through loops 1-3 of each endurance ride. The possibility of real-time, 'mid-ride' predictive modelling was explored by modelling both riding speeds and sudden changes in sp...
Uldahl M, Clayton HM.Information is needed to guide sport administrators in formulating rules for equipment use in competitions. Objective: To seek associations between spurs, bits, nosebands and whips with injuries in horses during competitions in four equestrian sports. Methods: Cross sectional study. Methods: Post competition evaluations were performed in 3143 horse/rider combinations competing in Danish Equestrian Federation competitions in dressage, showjumping, eventing and endurance by trained evaluators who recorded the presence and type of spurs, bits, nosebands, and whips. Further evaluations recorded no...
Lenoir A, Trachsel DS, Younes M, Barrey E, Robert C.Analysis of the heart rate variability (HRV) gains more and more importance in the assessment of training practice and welfare in equine industry. It relies on mathematical analyses of reliably and accurately measured variations in successive inter-beat intervals, measured as RR intervals. Nowadays, the RR intervals can be obtained through two different techniques: a heart rate meter (HRM) or an electrocardiogram (ECG). The agreement and reliability of these devices has not been fully assessed, especially for recordings during exercise. The purpose of this study was to assess the agreement of ...
Scheidegger MD, Gerber V, Bruckmaier RM, van der Kolk JH, Burger D, Ramseyer A.This study tested the hypothesis that adrenocortical function would be altered in horses with equine gastric ulcer syndrome (EGUS). Twenty-six sport horses competing at national or international levels in eventing (n=15) or endurance (n=11) were subjected to a gastroscopic examination and an adrenocorticotropic hormone (ACTH) stimulation test. Salivary cortisol concentrations were measured before (baseline) and after (30, 60, 90, 120 and 150min) IV ACTH injection (1μg/kg bodyweight). Within EGUS, two distinct diseases, equine squamous gastric disease (ESGD) and equine glandular gastric diseas...
Sloet van Oldruitenborgh-Oosterbaan MM, Genzel W, van Weeren PR.Welfare concerns over the reasons for interruption or termination of a sporting career in horses have been expressed. Objective: To study the career of competition horses and factors that influence career length. Methods: In 2004, 46,576 rider-horse combinations were registered with the Dutch National Equestrian Federation (KNHS) in dressage, show jumping, eventing and endurance. From this population, approximately 1% of horses in each discipline were selected at random and all recorded competition data from the KNHS registration system collected and supplemented by detailed rider/owner teleph...
Trachsel DS, Giraudet A, Maso D, Hervé G, Hauri DD, Barrey E, Robert C.The heart's physiological adaptation to aerobic training leads to an increase in heart chamber size, and is referred to as the Athlete's heart. However, heart dimensions are also related to body weight (BWT), body size, growth and (in some species) breed. There are few published data on the relationships between heart dimensions and growth or aerobic training in Arabian and Arabian-related endurance horses. Therefore the objective of the present study was to describe the influence of body dimensions (body length (BL), thoracic circumference (TC), withers height (WH)), BWT, age, gender, breed (...
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...
Muñoz A, Cuesta I, Riber C, Gata J, Trigo P, Castejón FM.Trot is a symmetric gait and asymmetry might appear or increase during endurance rides due to lameness, pain or excessive fatigue. Objective: To assess whether trot asymmetry increases during endurance competitions, whether it is possible to discriminate between horses with different performance and also its possible relationship with metabolism. Methods: Fifty-eight horses were filmed at trot during the lameness examinations in the vet-gates, before the competition (BCO), and after phases 1 (at 29 km), 2 (at 59 km) and 3 (at the end of the ride, at 80 km) and stride duration (SD) measured in ...
Wickler SJ, Greene HM, Egan K, Astudillo A, Dutto DJ, Hoyt DF.The relationship between fatigue and stride and/or muscle stiffness requires further study. Objective: To measure stride parameters in horses undergoing fatigue associated with running at submaximal speeds both on a treadmill and in an endurance ride. Objective: Stride frequencies and estimates of hindlimb stiffness would be decreased in fatigued horses. Methods: Horses were fatigued using 2 paradigms: run to exhaustion at a treadmill (4.5 m/sec, 6% incline) and finishing an 80 km endurance ride. Videos were digitised before and after fatigue and analysed for stride parameters: hind limb lengt...
Verdegaal EJMM, Howarth GS, McWhorter TJ, Boshuizen B, Franklin SH, Vidal Moreno de Vega C, Jonas SE, Folwell LE, Delesalle CJG.Establishing proper policies regarding the recognition and prevention of equine heat stress becomes increasingly important, especially in the face of global warming. To assist this, a detailed view of the variability of equine thermoregulation during field exercise and recovery is essential. 13 endurance horses and 12 trotter horses were equipped with continuous monitoring devices [gastrointestinal (GI) pill, heartrate (HR) monitor, and global positioning system] and monitored under cool weather conditions during four endurance rides over a total of 80 km (40 km loops) and intense trotter trac...
Holbrook TC, Birks EK, Sleeper MM, Durando M.Information is lacking regarding the influence of long distance exercise on the systemic concentration of cardiac troponin I (cTnI) in horses. Objective: To determine if the concentration of cTnI in horses competing in 80 and 160 km endurance races increases with exercise duration and if cTnI concentrations can be correlated with performance data. Methods: Blood samples for the measurement of cTnI and 3 min electrocardiogram recordings were obtained from horses prior to, during and after completion of 80 and 160 km endurance races at 3 ride sites during the 2004 and 2005 American Endurance Rid...
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...
Cappelli K, Mecocci S, Capomaccio S, Beccati F, Palumbo AR, Tognoloni A, Pepe M, Chiaradia E.Physical exercise has been associated with the modulation of micro RNAs (miRNAs), actively released in body fluids and recognized as accurate biomarkers. The aim of this study was to measure serum miRNA profiles in 18 horses taking part in endurance competitions, which represents a good model to test metabolic responses to moderate intensity prolonged efforts. Serum levels of miRNAs of eight horses that were eliminated due to metabolic unbalance (Non Performer-NP) were compared to those of 10 horses that finished an endurance competition in excellent metabolic condition (Performer-P). Circulat...
Cappelli K, Verini-Supplizi A, Capomaccio S, Silvestrelli M.The knowledge of molecular mechanisms of stress response in athlete horses can allow us to plan an appropriate and high-grade training to obtain better performance and to preserve horse welfare. It is well known that excessive muscular exercise can lead to a number of responses which may be associated with modification of the mRNA levels for a number of metabolic genes such as those involved in the immune response. In the present study cDNA-AFLP technique was applied to Arab endurance horses under stressing conditions to visualise variations of transcriptional profiles; 49 transcript derived f...
Serteyn D, Sandersen C, Lejeune JP, de la Rebière de Pouyade G, Ceusters J, Mouithys-Mickalad A, Niesten A, Fraipont A, van Erck E, Goachet AG....Intense physical exercise can induce the degranulation of neutrophils leading to an increase in plasma concentration of the neutrophil marker enzymes myeloperoxidase (MPO) and elastase (ELT). These enzymes have pro-oxidative and pro-inflammatory properties and may play a role in the exercised-induced muscular damage. Objective: To measure MPO and ELT concentrations in plasma and muscles of endurance horses and to correlate them to the extent of exercise-induced muscular damage. Methods: Seven endurance horses qualified on 120 km races were tested in this study. Neutrophil count, serum creatine...
Barnes A, Kingston J, Beetson S, Kuiper C.This study investigated the physiology of endurance horses competing in warm weather over technical terrain, a situation where horses may become metabolically compromised. Objective: There will be changes in physiological, haematological and biochemical variables as horses progress through the 160 km ride and horses detected clinically at the veterinary inspections as metabolically compromised will have significant differences in measured laboratory variables compared to horses that complete the ride successfully. Methods: Forty-eight horses competing in the Australian Tom Quilty 160 km endura...
Viu J, Jose-Cunilleras E, Armengou L, Cesarini C, Tarancón I, Rios J, Monreal L.Acid-base disturbances are traditionally assessed using the Henderson-Hasselbach equation. The simplified strong ion approach describes more accurately the complex acid-base and electrolyte abnormalities present in endurance horses. Objective: To describe acid-base and electrolytes changes in fit horses competing in a FEI*** 120 km endurance race and to compare the traditional vs. strong ion approaches. Methods: Thirty horses were initially enrolled in the study. Venous blood samples were obtained before the race (n = 25), at the second (n = 29; 65.4 km) and third vet-gates (n = 23, 97.4 km) a...
Page AE, Stewart JC, Fielding CL, Horohov DW.Previous work to evaluate various risk factors for failure to complete competitive endurance rides has examined clinicopathologic parameters, measurements of inflammation, and speed. Here, inflammatory markers were measured before, during, and after a long-distance, competitive endurance ride to examine the intraride dynamics of inflammatory marker expression and attempt to correlate those findings with whether a horse completed or failed to complete the ride. A total of 77 horses entered into the 2018 Tevis Cup Ride in California were enrolled in the study. Peripheral blood samples for mRNA i...
Jones JH, Carlson GP.The metabolic power required for sustained exercise in the horse is proportional to running speed. Moderately fast speeds require substantial energy expenditure and result in the generation of a massive metabolic heat load. Quantitative estimates of energy expenditure and heat production of horses at various running speeds were developed using empirically derived data from treadmill studies. Total metabolic power represents the sum of aerobic power indicated by the rate of oxygen consumption and net anaerobic power indicated by the rate of plasma lactate accumulation. These data were applied t...
García-Ballesteros S, Varona L, Valera M, Gutiérrez JP, Cervantes I.Ranking trait was used as a selection criterion for competition horses to estimate racing performance. In the literature the most common approaches to estimate breeding values are the linear or threshold statistical models. However, recent studies have shown that a Thurstonian approach was able to fix the race effect (competitive level of the horses that participate in the same race), thus suggesting a better prediction accuracy of breeding values for ranking trait. The aim of this study was to compare the predictability of linear, threshold and Thurstonian approaches for genetic evaluation of...
Bergero D, Assenza A, Schiavone A, Piccione G, Perona G, Caola G.The aim of this work was to evaluate the changes in the concentrations, after two rides different for distance covered, of different amino acids in endurance horses. Blood samples have been collected from horses just before the start, at the top of a steep slope (819 m difference in height) and just at the end of a 32-km endurance ride. A second group, competing in a 72 km endurance ride, has also been sampled immediately before and after the race. In serum samples, the concentrations of alanine, arginine, asparagine, glycine, isoleucine, histidine, leucine, lysine, methionine, ornithine, phen...
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...
Butudom P, Barnes DJ, Davis MW, Nielsen BD, Eberhart SW, Schott HC.To determine whether temperature of rehydration fluid influences voluntary rehydration by horses, six 2-3-year-old horses were dehydrated (4-5% body weight loss) by a combination of furosemide administration and 30 km of treadmill exercise. For the initial 5 min following exercise, horses were offered a 0.9% NaCl solution at 10, 20, or 30 degrees C. Subsequently, after washing and cooling out, voluntary intake of water at 10, 20, or 30 degrees C from 20 to 60 min after exercise was measured. Fluid intake (FI) during the first 5 min of recovery was 9.8+/-2.5,12.3+/-2.1 and 9.7+/-2.0L (p>0.05) f...
Barton MH, Williamson L, Jacks S, Norton N.To compare physiologic, hematologic, and selected serum and plasma biochemical variables obtained from horses competing in 48-, 83-, or 159-km endurance rides before competition and at the same cumulative distance points. Methods: 83 horses. Methods: Weight and rectal temperature measurements and blood samples were obtained from horses before, during, and after 1 of 3 rides conducted on the same day. Plasma protein (PP), lactate, WBC, serum electrolyte, and calcium concentrations; PCV; and creatine kinase (CK) activity were determined. Assessments were made to determine whether any differences...
Art T, Franck T, Gangl M, Votion D, Kohnen S, Deby-Dupont G, Serteyn D.In man, exercise of any type has been shown to induce neutrophil degranulation and respiratory burst activity, as well as an increase in plasma myeloperoxidase (MPO), a specific enzyme of neutrophil azurophilic granules with a strong oxidative activity. Until now, it is not known whether this is the same in horses. Objective: To study whether degranulation of blood neutrophils may be induced by exercise by measuring the total concentration of MPO and assess the possible influence of type of competition on this exercise-induced adjustment. Methods: Blood was sampled before, and 30 min after, th...
Rose RJ, Arnold KS, Church S, Paris R.Blood samples were taken from 20 horses competing in a 100 km endurance ride and plasma concentrations of sodium, potassium, chloride, bicarbonate and protein measured. Measurements were performed on samples taken before the ride (pre-ride), at the mid point and end of the ride and after a 30 min recovery period (post-ride). Sweat samples were collected from 6 horses competing in the endurance ride and 14 horses competing in a 3-day event competition and sweat concentrations of sodium, potassium and chloride measured. There were substantial decreases in plasma electrolyte concentrations, which...
Lopez-Rivero JL, Morales-Lopez JL, Galisteo AM, Aguera E.Muscle biopsies were taken from the middle gluteal muscle of 68 stallions (52 Andalusian [AN] and 16 Arab [AR]) ranging from six to 12 years of age. Seventeen AN horses and eight AR horses were untrained, while the remainder underwent active endurance training for 6 months. Fifteen AN horses were moderately endurance-trained while the other 20 AN horses and eight AR horses were strongly endurance-trained. Percentages of type I and type II fibres were similar in all groups (P greater than 0.05). The group of horses with the hardest training had a higher percentage of type IIA fibres (AN P less ...
Rose RJ, Hodgson DR, Sampson D, Chan W.Plasma biochemical values were measured in 14 horses, before a 160 km endurance ride, immediately after 85 km, immediately after 160 km, after 30 min recovery period and the day after the ride. For statistical analysis, a group of 7 horses that completed the ride at a mean speed of 234 metres per min (m/min) (Fast Group) was compared with 7 horses that completed the ride at a mean speed of 144 m/min (Slow Group). Estimations were made of sodium, potassium, chloride, bicarbonate, glucose, creatinine, urea, bilirubin, iron, total protein, albumin, calcium, phosphate, cholesterol, alkaline phosph...
Kang OD, Park YS.This study aimed to analyze the on heart rate, blood lactate concentration, packed cell volume (PCV) and hemoglobin (Hb) response after conducting exercise in endurance horses. Methods: A total of 20 healthy 3-9-years-old Jeju crossbreed mares (5.95 ± 2.24 year) of age and 312.65 ± 13.59 kg of weight) currently participating the endurance competition were used. The field tests selected for the experiment was gallop (approximately 8.3 m/s) along the selected 2.5 km course (a natural forest trail, not artificial road; a closed loop course). The horses were divided into three groups...
Rose RJ, Ilkiw JE, Martin IC.The effects of prolonged strenuous exercise on arterial and venous oxygen tension, carbon dioxide tension, pH, bicarbonate, standard bicarbonate, base excess, haemoglobin, packed cell volume and total plasma protein were studied in 36 horses during a 100 km endurance ride. There were significant changes in many parameters when pre-ride values were compared with both mid-ride and end of ride values. The prominent changes were the development of dehydration and a metabolic alkalosis. At the mid-ride sampling time those horses with higher heart rates had a greater degree of metabolic alkalosis th...
Sleeper MM, Durando MM, Holbrook TC, Payton ME, Birks EK.To determine whether echocardiographic variables differed between successful (elite) and less successful (nonelite) Arabian endurance horses. Methods: 34 Arabian horses that competed in endurance racing. Methods: Horses were assigned to either an elite or nonelite group on the basis of results of a previous competition, and a standardized echocardiographic examination was performed on each horse within 1 to 4 weeks after that competition. Multivariable logistic regression with backward stepwise elimination was used to create a prediction model for the determination of horse status (elite or no...
Kim JS, Hinchcliff KW, Yamaguchi M, Beard LA, Markert CD, Devor ST.Exercise training improves functional capacity in aged individuals. Whether such training reduces the severity of exercise-induced muscle damage is unknown. The purpose of the present study was to determine the effect of 10 wk of treadmill exercise training on skeletal muscle oxidative capacity and exercise-induced ultrastructural damage in six aged female Quarter horses (>23 yr of age). The magnitude of ultrastructural muscle damage induced by an incremental exercise test before and after training was determined by electron microscopic examination of samples of triceps, semimembranosus, an...
Ertelt A, Merle R, Stumpff F, Bollinger L, Liertz S, Weber C, Gehlen H.The purpose of this study was to assess a change in different blood parameters before and after a 160 km endurance race and to evaluate differences in cardiac biomarkers between horses that completed the race and horses that did not. The study population consisted of 52 healthy endurance horses. Horses participating in the study were assigned to three groups: horses that successfully completed the race ("finishers"), horses that failed to qualify at the veterinary check for primarily metabolic reasons ("metabolic") and horses that failed to qualify at the veterinary check for primarily gait re...
Cozzi MC, Strillacci MG, Valiati P, Rogliano E, Bagnato A, Longeri M.The Akhal-Teke horse (AKH) is native of the modern Turkmenistan area. It was introduced in Italy from 1991 to 2000 mainly as an endurance horse. This paper characterizes the genetic variability of the whole Italian AKH horse population and evaluates their inbreeding level by analyzing microsatellite markers and mitochondrial D-Loop sequences. Methods: Seventeen microsatellite marker loci were genotyped on 95 DNA samples from almost all the AKH horses bred in Italy in the last 20 years. Standard genetic variability measures (Ho, He, FIS) were compared against the same variables published on oth...
