bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of a global positioning and heart rate monitoring system to assess training load in a group of Thoroughbred racehorses
Authors: KINGSTON J. K. , SOPPET G. M. , ROGERS C. W. , FIRTH E. C. 
Published: June 2010

SummaryReasons for performing study: Training is an important variable for determining athletic success. Nonetheless, there has been minimal scientific evaluation of racehorse training programmes. Training of racehorses focuses on running the horses at certain speeds using a combination of a stopwatch and rider's ‘feel’ for a horse's work intensity. Consequently, actual work intensity for individual horses is not clearly defined.Objectives:To 1) utilise a combined global positioning system (GPS) and heart rate monitor system to quantify training intensity and physiological responses of a group of racehorses undergoing training and racing; and 2) compare the workload measured by the GPS to that timed and recorded daily by a racehorse trainer.Methods:Nineteen racehorses age 3 years were followed through a traditional training and racing programme over a 4 month period. Daily GPS and heart rate data together with the trainer's timing and distance data were collected while the horses were trained. Data were analysed using an ANOVA for repeated measures.Results:The combined GPS/heart rate monitoring system detected different heart rate responses in individual horses subjected to the same training workouts. The average speeds detected with the GPS system were in agreement with average speeds timed by the trainer. However, peak speeds reached during training were significantly greater (P<0.05) than those estimated with stopwatch timing. The horses average training speeds increased significantly over the duration of the training period.Conclusions and potential relevance:The results from this study show that a GPS/heart rate monitor system provides a reliable measure of daily workload in horses during training. This technology provides a detailed picture of horses' training sessions and has the potential to provide a greater insight into the types of training that may predispose horses to injury.
Correlation of race earnings with velocity at maximal heart rate during a field exercise test in Thoroughbred racehorses
Authors: GRAMKOW H. L. , EVANS D. L. 
Published: June 2010

SummaryReasons for performing study:Running ability of Thoroughbred racehorses is correlated with maximal oxygen uptake, and the velocity at maximal oxygen uptake is highly correlated with the velocity at maximal heart rate (VHRmax).Objective:To investigate the relationship between VHRmaxand racing performance, expressed as ‘peak dollars earned per race start’.Methods:Heart rate (HR) and velocity were recorded in 25 Thoroughbred racehorses during trotting and subsequent fast gallops in the field at velocities of 15–16 m/sec. Velocity was recorded by a global positioning system (GPS). Maximal HR (HRmax) and maximal velocity (Vmax) were identified, and a linear regression of HR on velocity for trotting and galloping data was constructed to derive VHRmax. Horses followed the training programme designed by one trainer, had at least 6 race starts and were clinically sound at the time of testing. Race earnings were expressed as the peak dollars per start in the horse's race career. Data were normalised using the results for the square root of ‘peak dollars earned per race start’ and the significance of associations between variables was determined by correlation coefficient and least square analyses.Results:Horses with higher VHRmaxearned significantly more dollars per race start (r = 0.41, P<0.05), and horses with VHRmaxless than 14.5 m/sec had mean earnings of less than A$2500 per race. There were no correlations between race earnings and either HRmaxor Vmax.Conclusion:Field studies of the relationship between HR and velocity with a GPS enable identification of horses with limited earnings.Potential relevance:This study demonstrates that a field test of fitness of Thoroughbred racehorses that correlates with retrospective racing ability is feasible. The technique has potential application in commercial training environments assisting with decisions concerning racing careers of individual racehorses.
The physiological responses to simulated race tests on a track and on a treadmill in Standardbred trotters
Authors: NOSTELL K. , FUNKQUIST P. , NYMAN G. , ESSÉN‐GUSTAVSSON B. , CONNYSSON M. , MUHONEN S. , JANSSON A. 
Published: June 2010

SummaryReason for performing study:It is unclear to what extent the physiological response to a standardised treadmill exercise test simulating racing conditions resembles the circulatory and metabolic response observed after a simulated race on a track.Objectives:To compare the physiological responses of a standardised treadmill exercise test used to simulate racing conditions and a simulated race performed on a track on the same Standardbred trotting horses, all in racing condition.Methods:Six Standardbred trotters in racing condition performed a standardised inclined treadmill exercise test protocol simulating racing conditions (ST) and a simulated race on a field track (FT). Heart and respiratory rates, haemoglobin, packed cell volume (PCV), glucose, pH, total carbon dioxide and potassium in venous blood and plasma lactate and total plasma protein were measured before and immediately after exercise and during recovery.Results:No differences were observed in heart rate, haemoglobin, PCV, total plasma protein, glucose concentrations after exercise and during recovery between the tests. Plasma lactate was higher and total carbon dioxide concentrations and pH were lower in blood at the end of exercise in the FT compared to the ST. Plasma lactate concentrations were still higher 30 min post exercise in the FT compared to the ST. Blood pH returned to resting values at 15 min of recovery for the ST and at 60 min of recovery for the FT. At 60 min of recovery total carbon dioxide concentrations had still not returned to resting values in any of the tests. Respiratory rate at the end of exercise and body temperature at 15 min of recovery was higher after the ST than the FT. Exercise caused an increase in blood potassium concentrations at the end of exercise in both tests, but concentrations were lower after the FT compared to the ST.Conclusions:The haemodynamic response to the ST test at the end of exercise and during recovery, assessed from heart rate, Hb, and PCV, was similar to the response observed in the FT test. The differences observed in plasma lactate, blood pH and TCO2concentrations between the ST and FT show that anaerobic metabolism was greater in the FT as this test included a finish at maximal speeds.Potential relevance:The treadmill test used in this study to simulate a race resembles the haemodynamic response but not the anaerobic metabolic response observed after a simulated race on a track.
A comparison of cross‐country recovery rates at CCI 2* with and without steeplechase competitions
Authors: MURRAY J. K. , SENIOR J. M. , SINGER E. R. 
Published: June 2010

SummaryReasons for performing study:Short format 3‐day events were introduced in 2004. Anecdotal reports suggested that horses were more tired on completion of the cross‐country phase of short format events when compared with horses completing the cross‐country phase of long format competitions, despite the absence ofPhases A, BandC.Objectives:To compare the physiological parameters and haematological parameters of horses that had completed the cross‐country phase of a short format (SF) and a long format (LF) CCI 2* competition.Methods:During a CCI 2* competition 69 competitors took part in the short format and 74 in the long format competition. Long format competitors completedPhases A, B, CandDand short format competitors completedPhase Donly.Phase D(the cross‐country course) was identical for both competitions. Two‐way ANOVA for repeated measures andpost hoctests were used to compare temperature, pulse and respiration rates of horses competing in both types of competition.Ttests were used to compare mean lactate and electrolyte concentrations, while U‐Mann Whitney tests were used to compare CK and AST levels measured in horses competing in the short and long formats of the event.Results:Training schedules, age and previous competition experience were not significantly different between horses competing in the SF and LF competitions. On completion ofPhase D, SF horses had significantly higher PCV and significantly lower ionised calcium concentrations when compared with LF horses. LF horses had significantly higher heart rates than SF horses 10 min prior to startingPhase Dand immediately after completingPhase D; however, no other significant differences were found between the 2 groups of horses.Conclusions:Only weak evidence was found to support the hypothesis that the workload for the horse in a SF CCI 2* competition is significantly different when compared to the LF CCI 2* competition.Potential relevance:There is no beneficial or detrimental effect on horses that complete short format CCI 2* competitions as compared to those that complete long format CCI 2* competitions but further research is required into the physiological response of horses at CCI 3* and CCI 4* short format competitions.
Retrospective study of predictive variables for maximal heart rate (HRmax) in horses undergoing strenuous treadmill exercise
Authors: VINCENT T. L. , NEWTON J. R. , DEATON C. M. , FRANKLIN S. H. , BIDDICK T. , McKEEVER K. H. , McDONOUGH P. , YOUNG L. E. , HODGSON D. R. , MARLIN D. J. 
Published: June 2010

SummaryReasons for performing study:Heart rate is one of the most commonly measured variables in equine exercise physiology and relative exercise intensity commonly expressed as % of maximal heart rate. A number of influences affect maximal heart rate (HRmax), including age of the horse but other factors have not been described.Objectives:To determine if fitness, health status, gender, breed, athletic use, body mass, in addition to age, are predictive of HRmaxin the horse.Methods:Maximal heart rate data from 328 horses which underwent treadmill exercise tests at 5 different laboratories were obtained retrospectively. Univariable linear regression analyses were performed on individual variables. Multiple linear regression analysis using a backward elimination modelling procedure was then used to relate the observed HRmaxvalues simultaneously with different predictive variables. Variables were retained in the final regression model if they or any of their categories were significantly predictive of HRmaxat P<0.05 and if there was a significant collective contribution to the model from inclusion of each variable, also at P<0.05.Results:Age, fitness status, laboratory, gender and breed/use (combined category) were all statistically significantly predictive of HRmax. Together these variables accounted for 41% of the variance in HRmax. Age alone accounted for only ˜13% of the variation between horses in HRmax. Neither body mass nor health status were significantly predictive.Conclusions:HRmaxin the horse declines with age but is also influenced by other factors. As the factors investigated accounted for only 41% of the variation between horses, other unidentified variables with a strong influence on HRmaxremain to be identified.Potential relevance:Factors such as fitness, age, gender, breed and use need to be considered when interpreting estimates or measurements of HRmax.
Cardiac arrhythmias during and after treadmill exercise in poorly performing Thoroughbred racehorses
Authors: JOSE‐CUNILLERAS E. , YOUNG L. E. , NEWTON J. R. , MARLIN D. J. 
Published: June 2010

SummaryReasons for performing study:The prevalence and severity of cardiac arrhythmias during exercise in athletic horses presented for poor performance is not well described.Objectives:To describe prevalence and severity of ventricular and supraventricular arrhythmias immediately before, during and immediately after standardised incremental treadmill exercise tests (IET) to fatigue in Thoroughbred horses during investigation of poor performance.Methods:The electrocardiograms (ECG) of 88 Thoroughbred racehorses, judged to be free of significant heart disease or arrhythmia at rest, were used. A modified base‐apex ECG was recorded throughout an IET to fatigue. Recordings were analysed independently by 2 observers. Twenty‐eight horses were diagnosed with dorsal displacement of the soft palate, 25 had varying degrees of soft palate instability and aryepiglottic fold collapse, 8 had other respiratory problems and, in 27 cases, no definitive diagnosis was reached.Results:Fifty‐five horses had at least one ventricular (VPD) or supraventricular (SVPD) depolarisation, 23 had only VPDs, 17 had only SVPDs and 15 had both in at least one exercise period. Premature depolarisations were seen predominantly during the first min of recovery from IET. The range of premature beats after exercise was 1–30 VPDs, and 1–9 SVPDs. No significant associations were observed between age, sex, race type, diagnosis, peak heart rate or run time to fatigue during IET and occurrence of either 1 premature beat or of more severe arrhythmias (multiple singles [>5] or pairs or paroxysms of premature depolarisations during peak exercise or immediately after exercise). However, a larger sample size would be required to have greater confidence in these associations.Conclusions:Isolated VPDs and SVPDs are frequently detected in poor performing racehorses during IET but their clinical relevance remains to be determined.Potential relevance:The guidelines for interpretation and clinical relevance of premature depolarisations observed during and immediately after treadmill exercise tests in poor performing Thoroughbred racehorses deserves further evaluation.
Effect of detraining on cardiorespiratory variables in young Thoroughbred horses
Authors: MUKAI K. , OHMURA H. , HIRAGA A. , ETO D. , TAKAHASHI T. , ASAI Y. , JONES J. H. 
Published: June 2010

SummaryReasons for performing study:Thoroughbred racehorses often experience interruptions to their training. Identifying the effects of these changes and how they alter athletic performance might provide an insight on to how to prevent these changes from occurring.Hypothesis:Training and detraining young Thoroughbreds alters their aerobic capacities with correlated changes in circulatory capacities; if horses remained spontaneously active in a pasture during their detraining period, their decreases in aerobic capacity during detraining would be reduced.Methods:We trained 6 Thoroughbred yearlings for 6 months using a conventional yearling race training programme. They were then detrained for 10 weeks with free range on pasture for 8 h/day and stall rest at night. Treadmill measurements of O2transport variables were made before training (PRE), after training (TR) and after detraining (DT). A step‐test protocol identified each horse's aerobic capacity (VO2max) and speed to attain it, and a steady‐state run at VO2maxwas used to quantify O2transport variables at each time period.Results:The mass‐specific and whole‐body VO2max, cardiac output (Q) and stroke volume (Vs) increased from PRE to TR. All mass‐specific values decreased significantly from TR to DT; however, because body mass increased by 8.3% from TR to DT, none of the variables changed significantly from TR to DT on a whole‐body basis.Conclusions:Changes in aerobic capacity are highly correlated with changes in Vs and circulatory capacity during training and detraining. Exercise activity of trained young horses free at pasture for 8 h/day is sufficient to maintain VO2max, Q and Vsduring 10 weeks of DT.Potential relevance:Aerobic and cardiovascular fitness may be maintained in young Thoroughbred horses during at least 10 weeks of detraining by maintaining modest spontaneous exercise activity.
Heart rate variability in trotters during different training periods
Authors: KINNUNEN S. , LAUKKANEN R. , HALDI J. , HANNINEN O. , ATALAY M. 
Published: June 2010

SummaryReasons for performing study: Endurance training induces changes in autonomic nervous system functions. High intensity training includes the risk of overtraining, in man and horse. Heart rate variability (HRV) is a noninvasive measurement of the autonomic regulation of the heart rate, which is quick and easy to measure with modern telemetric technology.Hypothesis: Since HRV is affected by changes in the autonomic nervous system, it might be an early stage indicator of poor recovery from a previous bout of exercise or overreaching or overtraining in horses in general.Methods: The aim of the study was to monitor recovery and the possible overtraining status in horses by measuring HRV. The measurements reflected the responses of the previous day activities during different training periods including basic training, precompetition and competition during a one‐year follow‐up.Results: HRV was at the highest during precompetition period (P<0.05) and it decreased significantly during competition period (P<0.05), indicating an increased stress load in the competition period. Walking increased HRV significantly compared to complete rest or jogging as previous day activities during basic training and precompetition periods (P<0.05). This finding suggests that horses are more relaxed during moderate exercise than standing still or anaerobic exercise.Conclusions: HRV can be used to monitor the cardiovascular responses to training in horses but confirmatory measures may also be required in addition to HRV to exclude other possible causes of underperformance.
Low dose exogenous erythropoietin elicits an ergogenic effect in Standardbred horses
Authors: McKEEVER K. H. , AGANS J. M. , GEISER S. , LORIMER P. J. , MAYLIN G. A. 
Published: June 2010

SummaryReasons for performing study:Recombinant human erythropoietin (rhuEPO) causes an increase in red blood cell production and aerobic capacity in other species; however, data are lacking on effects in the horse.Hypothesis:This study tested the hypothesis that rhuEPO administration would alter red cell volume (RCV), aerobic capacity (VO2max) and indices of anaerobic power.Methods:Eight healthy, unfit mares accustomed to the laboratory and experimental protocols were randomly assigned to either a control (CON, n=4; 3 ml saline 3 times/week for 3 weeks) or EPO group (EPO, n = 4, 50 iu/kg bwt rhuEPO/3 ml saline 3 times/week for 3 weeks). Exercise tests (GXT) were performed on a treadmill (6% incline), 1 week before and 1 week after treatment. The GXT started at 4 m/sec, with a 1 m/sec increase every 60 sec until the horse reached fatigue. Oxygen uptake was measured via an open flow indirect calorimeter. Blood samples were collected before, during (each step) and 2 and 15 min post GXT to measure packed cell volume (PCV), haemoglobin concentration (Hb), blood lactate concentration (LA) and plasma protein concentration (TP). Plasma volume (PV) was measured using Evans Blue dye. Blood volume (BV) and RCV were calculated using PCV from the 8 m/sec step of the GXT.Results:There were no alterations (P>0.05) in any parameters in CON horses. By week 3, EPO produced increases (P<0.05) in resting PCV (37 ± 2 vs. 51 ± 2) and Hb (37%). RCV (26%) and VO2max(19%) increased, but BV did not change (P>0.05) due to decreased PV (‐11%, P<0.05). There was a significant increase in velocity at VO2maxand LApeakfor horses treated with rhuEPO and substantial decrease (P<0.05) in VO2recovery time when the pretreatment GXT was compared to the post treatment GXT. No differences (P<0.05) were detected for TP, VLA4, run time or Vmax.Conclusions:Low dose rhuEPO administration increases RCV and aerobic capacity without altering anaerobic power.Potential relevance:This study demonstrates that rhuEPO enhances aerobic capacity and exercise performance, a question relevant to racing authorities.
Influence of training on plasma adrenaline and noradrenaline kinetics in untrained Standardbreds
Authors: BARAGLI P. , DUCCI M. , GATTA D. , GAZZANO A. , SIGHIERI C. 
Published: June 2010

SummaryReasons for performing study:Catecholamines (CAT) play an important role in modulating the response to exercise. But the kinetics of CAT changes during exercise are difficult to study due to their short biological half‐life.Objectives:Learning about variations in plasma CAT levels during training could furnish new information regarding sweating, redistribution of blood flow and energy metabolism.Methods:Four untrained Standardbreds, adapted to treadmill work, were used to determine the influence of training on plasma adrenaline (A) and noradrenaline (NA) kinetics. Horses underwent a standardised exercise test (SET) on treadmill before (SET1), and 1 (SET2) and 2 months after (SET3) the start of a moderate training period on treadmill. The SET procedure was: warm‐up and a single step of 2 min at 200 beats/min heart rate (SS). The automatic blood collection system (that has been carried out during SS) and the preparation of the horses have been described previously. The system was programmed to obtain a blood sample every 15 sec (8 blood samples per SS). Analyses were performed by HPLC. Training progress was monitored by means of anaerobic threshold velocity (V4) and the velocity during SS (V200). Wilcoxon's test was used for statistical analysis.Results:Decreased levels of A and NA with significant differences between SET1/SET2 and SET1/SET3 for A (P=0.007) and NA (P=0.007) were found. There were no differences between SET2 and SET3 for A (P=0.195) and NA (P = 0.054).Conclusions:Training appears to influence the level of plasma CAT and this influence is greater during the first training period in untrained Standardbreds.Potential relevance:It may prove interesting to associate the study of training‐induced modifications of the concentration of plasma CAT with thermoregulation, which is under catecholaminergic control and undergoes important adaptations during training.
The effect of adrenergic suppression induced by guanabenz administration on exercising Thoroughbred horses
Authors: COLAHAN P. T. , SAVAGE K. A. , TEBBETT I. R. , RICE B. L. , JACKSON C. A. , FRESHWATER L. 
Published: June 2010

SummaryReasons for performing study:Adrenergic activity accompanies intense exercise and mediates physiological and metabolic responses to exercise. Guanabenz, an antihypertensive drug marketed for human usage, depresses brain vasomotor and cardioaccelerator centres, blocks peripherally adrenergic neurons and is reportedly used as a calming agent in horses but little is known of its effects in the species.Objectives:To determine if guanabenz induces measurable signs of adrenergic suppression on fit Thoroughbred horses undergoing intense exercise.Methods:In a random crossover design, 12 exercise conditioned Thoroughbred horses each received guanabenz (0.08 mg/kg bwt i.v.) and placebo at 3‐week intervals. An incremental exercise test to exhaustion on a treadmill followed treatment by 1 h. Heart rate, oxygen consumption, carbon dioxide production, plasma lactate, catecholamines, adrenocorticotropic hormone (ACTH) and cortisol, and time to fatigue were monitored. Statistical analysis was performed using mixed‐effects linear modelling.Results:Mean heart rate during the exercise period was lower in guanabenz‐treated horses (P=0.04). Mean concentrations of plasma cortisol (P=0.02) and adrenaline (P=0.03) were lower for guanabenz‐treated horses during the exercise period. Mean run time was slightly but not significantly longer for guanabenz‐treated horses, (P = 0.053). No significant effects of guanabenz administration were found for oxygen consumption, carbon dioxide production nor for plasma lactate, noradrenaline and ACTH concentrations.Conclusion:Guanabenz administration induced signs of adrenergic suppression including plasma cortisol and adrenaline concentrations and heart rate and may enhance endurance, but did not eliminate increases in hormone concentrations induced by exercise. Clear determination of a positive performance effect of adrenaline, but not noradrenaline, suppression is needed before clinical significance can be determined.