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Author Hada, T.; Ohmura, H.; Mukai, K.; Eto, D.; Takahashi, T.; Hiraga, A.
Title Utilisation of the time constant calculated from heart rate recovery after exercise for evaluation of autonomic activity in horses Type Journal Article
Year 2006 Publication Equine Veterinary Journal. Supplement Abbreviated Journal Equine Vet J Suppl
Volume Issue 36 Pages (down) 141-145
Keywords Animals; Atropine/pharmacology; Autonomic Nervous System/drug effects/*physiology; Exercise Test/veterinary; Female; Heart Rate/*physiology; Horses/*physiology; Male; Oxygen Consumption/*physiology; Parasympatholytics/*pharmacology; Physical Conditioning, Animal/*physiology; Physical Fitness/physiology; Propranolol/pharmacology
Abstract REASONS FOR PERFORMING STUDY: Heart rate (HR) recovery immediately after exercise is controlled by autonomic functions and the time constant (T) calculated from HR recovery is thought to be an index of parasympathetic activity in man. OBJECTIVES: To investigate whether it is possible to evaluate autonomic function using the time constant in horses. METHODS: Five Thoroughbred horses were subjected to a standard exercise test. Following pre-medication with saline, atropine and/or propranolol, the horses ran for 2.5 min at a speed of 8 m/sec at a 10% incline and T was calculated from HR after the exercise. Secondly, 7 Thoroughbred horses were then trained for 11 weeks and T and maximal oxygen uptake (VO2max) measured at intervals of 1 or 2 weeks. In 6 horses, T with atropine pre-medication was also measured before and after the whole training period. Furthermore, the HR variability at rest was evaluated by power spectral analysis at intervals of 3 or 4 weeks. RESULTS: Time constant was increased by atropine and/or propranolol pre-medication, decreased with the progress of training and inversely correlated with VO2max during training (r = 0.43, P<0.005). Parasympathetic blockade significantly decreased T only after and not before, the training; however, T was lower in post training than in pretraining, irrespective of parasympathetic blockade. On the other hand, parasympathetic activity at rest was attenuated and sympathetic activity became predominant following the training. CONCLUSION: Heart rate recovery is affected by sympathetic withdrawal and parasympathetic reactivation in horses and suggests that physical training hastened HR recovery by improving the parasympathetic function after exercise with aerobic capacity. However, the effects of other factors need to be considered because the training effect appeared on T even under parasympathetic blockade. The parasympathetic activity at rest is in contrast to that after exercise, suggesting that T does not reflect parasympathetic activity at rest. POTENTIAL RELEVANCE: If demonstrated how HR recovery is controlled after exercise, its analysis will be important in the evaluation of physical fitness in horses.
Address Equine Science Division, Hidaka Training and Research Center, Japan Racing Association, 535-13 Nischicha, Urakawa-cho, Uraakawagun, Hokkaido, Japan
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Notes PMID:17402409 Approved no
Call Number Equine Behaviour @ team @ Serial 4010
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Author Voss, B.; Mohr, E.; Krzywanek, H.
Title Effects of aqua-treadmill exercise on selected blood parameters and on heart-rate variability of horses Type Journal Article
Year 2002 Publication Journal of Veterinary Medicine. A, Physiology, Pathology, Clinical Medicine Abbreviated Journal J Vet Med A Physiol Pathol Clin Med
Volume 49 Issue 3 Pages (down) 137-143
Keywords Animals; Electrocardiography/veterinary; Exercise Test/veterinary; Female; Heart Rate/*physiology; Hemoglobins/metabolism; Horses/*physiology; Lactic Acid/blood; Male; Physical Conditioning, Animal/*physiology; Water
Abstract The objectives of the present study were to investigate the effects of Aquatraining of horses (aqua-treadmill exercise; treadmill manufactured by Equitech – L.u.S. Equipment, Warendorf, Germany) on selected blood parameters [lactic acid concentration (mmol/l), haemoglobin content (g/l)] and on heart-rate variability (HRV) [heart rate (beats per min; b.p.m.), standard deviation of all NN-intervals (SDNN; ms), normalized power of the low and high frequency band (LFnorm, Hfnorm; au), % recurrence, % determinism and ratio(corr)]. Seven horses performed six exercise tests with different work loads (walking (x = 1.56 +/- 0.08 m/s) and trotting (x = 2.9 +/- 0.13 m/s): dry, water above the carpus and water above the elbow). The standardized test-protocol was: 5 min warm-up at walk while the water was pumped in, followed by the 20-min exercise period at walk or trot, followed by a 5-min walk while pumping out the water. Blood samples were taken prior to each test at rest in the stable, as well as exactly 5 min after the end of the 20-min exercise period. Electrocardiograms were recorded during rest and the 20-min exercise period. Compared to rest, neither the chosen velocities, the two water levels, nor the dry tests led to a significant increase of the lactic acid concentration in any horse. The haemoglobin content showed a significant increase as a result of exercise. Significant differences could be found between the heart rates at rest and the six exercise tests and between the mean of the levels 'walking' and the mean of the levels 'trotting'. An exercise-induced change of HRV was characterized by a decreasing SDNN, a significantly higher LFnorm (sympathetic influence) combined with a significantly lower HF(norm) power (parasympathetic activity) and a rising degree of order (significantly higher % determinism and nearly unchanged % recurrence) and stability (significantly rising ratio(corr)) of the recurrence plot. In conclusion, the used training-protocol for aqua-treadmill exercises only represents a medium-sized aerobic work load for horses, but the different levels of burden were indicated especially by changes in HRV.
Address Institute for Veterinary Physiology of the Free University Berlin, Germany
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Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0931-184X ISBN Medium
Area Expedition Conference
Notes PMID:12019954 Approved no
Call Number Equine Behaviour @ team @ Serial 4049
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Author Gramkow, H.L.; Evans, D.L.
Title Correlation of race earnings with velocity at maximal heart rate during a field exercise test in thoroughbred racehorses Type Journal Article
Year 2006 Publication Equine Veterinary Journal. Supplement Abbreviated Journal Equine Vet J Suppl
Volume Issue 36 Pages (down) 118-122
Keywords Animals; Exercise Test/veterinary; Female; Geographic Information Systems; Heart Rate/*physiology; Horses/*physiology; Linear Models; Male; Oxygen Consumption/*physiology; Physical Conditioning, Animal/*economics/*physiology; Physical Fitness/physiology; Running; Sports/economics
Abstract REASONS 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 VHRmax and 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 VHRmax earned significantly more dollars per race start (r = 0.41, P<0.05), and horses with VHRmax less than 14.5 m/sec had mean earnings of less than A$2500 per race. There were no correlations between race earnings and either HRmax or 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.
Address Faculty of Veterinary Science, University of Sydney, New South Wales 2006, Australia
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Notes PMID:17402405 Approved no
Call Number Equine Behaviour @ team @ Serial 4012
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Author Leleu, C.; Cotrel, C.
Title Body composition in young standardbreds in training: relationships to body condition score, physiological and locomotor variables during exercise Type Journal Article
Year 2006 Publication Equine Veterinary Journal. Supplement Abbreviated Journal Equine Vet J Suppl
Volume Issue 36 Pages (down) 98-101
Keywords Adipose Tissue/metabolism; Animals; Body Composition/*physiology; Body Constitution/*physiology; Body Weight/physiology; Exercise Test/veterinary; Female; Gait/physiology; Heart Rate/*physiology; Horses/*physiology; Lactates/blood; Male; Muscle, Skeletal/metabolism; Physical Conditioning, Animal/*physiology
Abstract REASONS FOR PERFORMING STUDY: Body composition is an essential factor in athletic performance of human sprinters and long distance runners. However, in horses, many questions remain concerning relationships between body composition and performance in the different equine activities. OBJECTIVES: To determine relationships between body composition, body score, physiological and locomotor variables in a population of young Standardbreds in training. METHODS: Twenty-four 2-year-old Standardbreds were studied, body condition on a scale 0-5 and bodyweight recorded, and height at withers measured. Percentage of fat (%F), fat mass (FM) and fat free mass (FFM) were estimated echographically. During a standardised exercise test on the track, velocity, heart rate, respiratory frequency and blood lactate concentrations were measured. V4 and V200 (velocity for a blood lactate concentration of 4 mmol/l and velocity of 200 beats/min) calculated. Basic gait variables were measured at 3 different speeds with an accelerometric device. RESULTS: Body composition variables: %F and FM were significantly related to body condition score and physiological variables. Body score was highly correlated to %F (r = 0.64) and FM (r = 0.71). V4 was negatively correlated to %F (r = -0.59) and FM (r = -0.60), P<0.05. V200 was also negatively related to %F and FM, (r = -0.39 and r = -0.37, respectively, P<0.1). No relationships were found between body composition and gait characteristics. CONCLUSIONS: Body composition was closely related to indirect measurements of aerobic capacity, which is a major factor of athletic performance in middle distance running horses. POTENTIAL RELEVANCE: As in human athletes, trainers should take special note to evaluate optimal bodyweight and body composition of race horses to optimise performance.
Address Pegase Mayenne, Departement de Medecine du Sport, Centre Hospitalier, 53 015 Laval, France
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Language English Summary Language Original Title
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Area Expedition Conference
Notes PMID:17402400 Approved no
Call Number Equine Behaviour @ team @ Serial 4015
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Author Kraus-Hansen, A.E.; Fackelman, G.E.; Becker, C.; Williams, R.M.; Pipers, F.S.
Title Preliminary studies on the vascular anatomy of the equine superficial digital flexor tendon Type Journal Article
Year 1992 Publication Equine veterinary journal Abbreviated Journal Equine Vet J
Volume 24 Issue 1 Pages (down) 46-51
Keywords Angiography/veterinary; Animals; Exercise Test/veterinary; Forelimb; Horses/*anatomy & histology/surgery; Microcirculation; Microscopy, Electron, Scanning; Tendons/*blood supply/surgery/ultrastructure
Abstract The vascular and microvascular anatomy of normal equine superficial digital flexor tendons was studied by dissection of vinyl-perfused specimens and by microangiography on high detail film. The presence of an extensive intratendinous vascular latticework was confirmed, and a 'nutrient artery' described closely associated with the accessory ligament of the superficial digital flexor tendon (proximal check ligament). Circumferential stripping of the paratenon from the tendon to eliminate afferent vessels was performed bilaterally in three horses and unilaterally in a fourth, followed by a treadmill training regimen. No resulting intratendinous lesions could be documented on gross post mortem and histological examination at three, 10, or 35 days post operatively. There was mild paratendinous proliferation in all instances. In one horse, four intratendinous ligatures were placed within the medial and lateral borders of the contralateral tendon to isolate further from its blood supply a 10 cm segment. Gross lesions at 35 days post operatively included a marked paratendinous response involving the entire 10 cm segment, and a darkened, soft focus within the core of the tendon. Histopathology and electron microscopy demonstrated focal degeneration. It was concluded that the blood supply of the normal equine superficial digital flexor tendon is primarily intratendinous, rather than paratendinous as previously thought. The lesions in one horse similar to those in naturally occurring tendinitis supported a vascular aetiology of the disease, and set the groundwork for studies aimed at the development of a clinically relevant tendinitis model.
Address Department of Surgery, Tufts University School of Veterinary Medicine, North Grafton, Massachusetts 01536
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0425-1644 ISBN Medium
Area Expedition Conference
Notes PMID:1555540 Approved no
Call Number refbase @ user @ Serial 151
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Author Rhodin, M.; Johnston, C.; Holm, K.R.; Wennerstrand, J.; Drevemo, S.
Title The influence of head and neck position on kinematics of the back in riding horses at the walk and trot Type Journal Article
Year 2005 Publication Equine Veterinary Journal Abbreviated Journal Equine Vet J
Volume 37 Issue 1 Pages (down) 7-11
Keywords Acceleration; Animals; Back/*physiology; Biomechanics; Exercise Test/veterinary; Female; Gait/*physiology; Head/*physiology; Horses/*physiology; Male; Movement/physiology; Neck/*physiology; Walking/physiology
Abstract REASONS FOR PERFORMING STUDY: A common opinion among riders and in the literature is that the positioning of the head and neck influences the back of the horse, but this has not yet been measured objectively. OBJECTIVES: To evaluate the effect of head and neck position on the kinematics of the back in riding horses. METHODS: Eight Warmblood riding horses in regular work were studied on a treadmill at walk and trot with the head and neck in 3 different predetermined positions achieved by side reins attached to the bit and to an anticast roller. The 3-dimensional movement of the thoracolumbar spine was measured from the position of skin-fixed markers recorded by infrared videocameras. RESULTS: Head and neck position influenced the movements of the back, especially at the walk. When the head was fixed in a high position at the walk, the flexion-extension movement and lateral bending of the lumbar back, as well as the axial rotation, were significantly reduced when compared to movements with the head free or in a low position. At walk, head and neck position also significantly influenced stride length, which was shortest with the head in a high position. At trot, the stride length was independent of head position. CONCLUSIONS: Restricting and restraining the position and movement of the head and neck alters the movement of the back and stride characteristics. With the head and neck in a high position stride length and flexion and extension of the caudal back were significantly reduced. POTENTIAL RELEVANCE: Use of side reins in training and rehabilitation programmes should be used with an understanding of the possible effects on the horse's back.
Address Department of Anatomy, Swedish University of Agricultural Sciences, 750 07 Uppsala, Sweden
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0425-1644 ISBN Medium
Area Expedition Conference
Notes PMID:15651727 Approved no
Call Number Equine Behaviour @ team @ Serial 3657
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