The Athletic Horse - E-Book (eBook)

Front cover 1
The athletic horse principles and practice of equine sports medicine second edition 2
Copyright page 3
Dedication 4
Contributors 5
Preface 7
Table of contents 8
I Structure considerations in equine sports medicine 10
1 An overview of performance and sports medicine 10
Equine sports medicine and the athletic horse 10
Energy demands of exercise and implications for training 10
Training and musculoskeletal injuries 11
Limitations to performance 11
Overview of the application of sports medicine and exercise science in the athletic horse 12
Aim of scientific investigation 12
Techniques and instrumentation needed for laboratory research of the athletic species 12
Treadmill 12
Respiratory gas analysis and determination of o2max 13
Maximal oxygen consumption 13
Blood oxygen content 13
Heart rate 13
Blood tests 14
Blood lactate concentration 14
Blood glucose and insulin concentrations 14
Hormone profiles 14
Blood enzyme assays 14
Muscle biopsy 15
Validation of newer technical systems for use in horses 15
Heart rate monitors 15
Blood or plasma lactate analyzers 15
Respiratory gas analyzers 15
Global positioning system 16
Future of equine sports medicine 16
Conclusion 16
References 17
2 Comparative aspects of exercise physiology 18
Main athletic species 18
The human athlete 18
Distances 18
The equine athlete 19
Distances 19
The racing camel 19
Racing dogs: The greyhound 19
Distances 19
Racing dogs: The husky 19
Comparative physiology of the athletic species 19
Aerobic power or o2max 19
Oxygen consumption 19
Cardiac output 19
Stroke index 19
Blood oxygen content 20
O2max as a predictor of athletic ability 20
Blood lactate response to exercise 21
Muscle fiber types 21
Relevance of physiologic testing 21
History of improvement in racing times in the different species 21
Improvement in racing times in horses, dogs, and humans 21
Factors determining athletic ability in any species 22
Genetics 22
Environment 23
Athletic nutrition 23
Track surfaces 23
Shoes 23
The jockey 24
Training 24
Training methodology 24
Conclusion 25
References 25
II Physiology of exercise and performance 28
3 Energetic considerations of exercise 28
Production of energy 28
Oxidative phosphorylation 28
Aerobic glycolysis 29
Fatty acid utilization 29
Anaerobic phosphorylation 29
Phosphocreatine reaction 30
Myokinase reaction 31
Anaerobic glycolysis 31
Regulation of aerobic and anaerobic pathways 31
Energy pathway contributions in the exercising horse 31
Energy substrates 32
Carbohydrates 33
Fat 33
Protein 33
Effects of dietary alterations on energy substrate utilization 33
Energy expenditure 34
Aerobic power or oxygen uptake 34
Oxygen uptake at rest and during submaximal exercise 34
Speed 34
Load 35
Slope and terrain 35
Duration 36
Temperature 36
Rider 36
Maximum aerobic power 36
Anaerobic power 36
Anaerobic threshold 38
Postexercise oxygen consumption 38
Energy partitioning 38
Economy of locomotion 39
Fatigue 40
Conclusion 40
References 41
4 Nutrition of the performance horse 43
Equine digestion, absorption, and metabolism 43
Digestion and absorption 43
Nutrient metabolism 44
At rest 44
During exercise 45
During recovery from exercise 47
Nutrient requirements of performance horses 48
Energy 49
Protein and amino acids 51
Minerals 52
Vitamins 54
Use of dietary supplements for performance horses 55
Antioxidants 56
Creatine 57
Carnitine 57
Amino acids 57
Other supplements 58
Feed selection 58
Forages 58
Concentrates 59
Nutritional supplements 60
Feeding management 60
References and suggested readings 61
Suggested readings 64
5 Hematology and biochemistry 65
Resting hemogram, leucogram, and serum or plasma biochemical variables 65
Blood collection techniques 65
Sample handling 65
Sample processing and accuracy 65
Resting hemogram 66
Normal ranges, monitoring, and performance 66
Maximal packed cell volume or hematocrit 68
Factors affecting the resting hemogram 68
Attitude of the horse 68
Effect of feeding 68
Exercise 69
Effect of prior exercise and diurnal variation 69
Overtraining 69
Erythrocyte changes with intense exercise 69
Leucogram 69
Factors affecting the resting leucogram 70
Excitement and intense exercise (effect of catecholamines) 70
Stress and moderate intensity exercise (effect of corticosteroids) 70
Overtraining 70
Subclinical disease 71
Normal resting serum or plasma biochemistry 71
Electrolytes 71
Sodium 71
Potassium 71
Chloride 72
Calcium and phosphate 72
Muscle-derived enzymes 72
Overtraining and subclinical muscle damage 72
Muscle disease recurrent rhabdomyolysis and delayed onset muscle soreness 73
Liver enzymes 73
Protein measurements 73
Measurements of renal function 73
Changes in plasma or serum biochemical values associated with exercise 73
Electrolytes and acid–base status 73
Maximal exercise 73
Prolonged low-intensity exercise 74
Speed and endurance phase (day 2) of a 3-day event 74
Renal responses to exercise 74
Blood lactate and glucose changes with exercise 74
Hematologic and biochemical changes associated with training 75
Hematologic changes with training 75
Racehorse training 75
Endurance training 75
Changes in plasma or serum biochemical values associated with training 75
Conclusion 76
References 76
6 Physiology of acid–base balance and fluid shifts with exercise 78
Body fluid compartments 78
Plasma osmolarity and the concentration of key electrolytes 80
Plasma concentration versus plasma content 82
Electrolytes and acid–base status 82
Maximal exercise 83
Low–intensity exercise 85
Effects of acute exercise on fluid and electrolyte balance 85
Intercompartmental fluid shifts at the onset of exercise 85
Fluid and electrolyte losses associated with longer acute exercise 86
Environment, exercise, and sweat loss 87
Thirst, drinking, and electrolyte intake 88
Renal function during exercise 88
Effects of exercise on renal blood flow 89
Effect of exercise on glomerular filtration rate and filtration fraction 89
Renal tubular function and excretion during exercise 90
Postexercise changes in renal function 92
The adaptive (training) response to repeated exercise 92
Hypervolemia 92
Red blood cell hypervolemia and overtraining syndrome 93
Effects of aging on the acute and chronic response to exercise 94
Conclusion 95
References 95
7 Endocrine and immune responses to exercise and training 97
Endocrine system and hormones 97
Major endocrine glands and hormones 99
Pituitary gland 99
Anterior pituitary hormones 99
Growth hormone 99
Thyrotropin 100
Adrenocorticotropic hormone 100
Endorphins, enkephalins, and dynorphins 100
Posterior pituitary hormones 101
Arginine vasopressin 101
Thyroid 101
Triiodothyronine and thyroxine 102
Calcitonin 102
Parathyroid gland 102
Adrenals 102
Hormones produced by the adrenal medulla (catecholamines) 102
Primary hormones produced by the adrenal cortex 103
Aldosterone 103
Cortisol 104
Pancreas 104
Insulin 104
Glucagon 105
Other pancreatic hormones 105
Pancreatic polypeptide 105
Somatostatin 105
Circulating gastrointestinal (“gut”) hormones 105
Gastric inhibitory peptide 105
Vasoactive intestinal polypeptide 106
Gastrin 106
Other gastrointestinal peptides with endocrine or paracrine actions 106
Hormones related to appetite and energy balance 106
Leptin 106
Adiponectin 107
Ghrelin 107
Cholecystokinin 107
Kidneys 108
Renin 108
Erythropoietin 108
Heart and blood vessels 109
Atrial natriuretic peptide 109
Endothelin 110
Gonads and reproductive hormones 111
Follicle stimulating hormone 111
Luteinizing hormone and estradiol interactions 111
Luteinizing hormone and testosterone interactions 112
Endocrine mediation of short–term control of cardiovascular function 112
Endocrine control of metabolism during acute exercise 113
References and suggested reading 114
Suggested reading 116
8 Thermoregulation 117
Mechanisms of heat transfer 117
Radiation 117
Convection 117
Conduction 118
Evaporation 118
Regulation of internal body temperature 118
Physiologic thermoregulatory mechanisms for heat loss 118
Mechanisms of evaporative heat loss 119
Humans versus horses 119
Evaporative heat loss from the respiratory tract 119
Evaporative heat loss from sweating 119
Function of sweat glands 119
Chemical composition of sweat: Humans 119
Formation of sweat in humans 119
Equine sweat composition 120
Innervation of the sweat glands 120
Circulatory adjustments for thermoregulation 120
Skin blood flow 120
Cardiac output 121
Redistribution of cardiac output 121
Thermoregulation during exercise 121
Energy exchanges during exercise 121
Estimations of heat production during exercise 122
Amount of heat dissipated by sweating 123
Estimation of sweat losses during exercise 123
Amount of heat dissipated via the respiratory tract 123
Cardiovascular function responses to augment thermoregulation during exercise 124
Skin blood flow during exercise 124
Cardiac output during exercise 124
Redistribution of cardiac output during exercise 124
Effects of combined exercise and heat stress 124
Cardiac output 124
Redistribution of cardiac output 124
Clinical problems associated with heat stress and exercise in horses 125
Exhaustive disease syndrome 125
Effect of sweat loss on body fluid composition 126
Pathogenesis 126
Clinical signs 127
Clinicopathologic alterations 127
Treatment 127
Prevention of heat stress in horses 128
Preparation for the event 128
Physical training 128
Heat acclimatization 128
Electrolyte supplementation 129
Management at the event 129
Weather conditions at the event 129
Watering the horse during the ride 129
Cooling the horse during the ride 129
Synchronous diaphragmatic flutter 129
Clinical signs 130
Pathogenesis 130
Treatment 130
Chronic synchronous diaphragmatic flutter 130
Heat stress (stroke) 130
Predisposing factors in humans 130
Pathogenesis 130
Horses at risk of developing heat stress 131
Clinical signs 131
Treatment 131
Prevention 131
Anhidrosis 132
Clinical signs 132
Diagnosis 132
Pathogenesis 132
Treatment 132
Conclusion 132
References and suggested reading 132
9 The respiratory system: Anatomy, physiology, and adaptations to exercise and training 134
Introduction 134
Importance of the respiratory system in the athletic horse 134
Functions of the respiratory system in the horse 134
External factors influencing pulmonary function 134
Structural peculiarities of the equine respiratory system and their functional impact 134
Airways 134
Nostrils 134
Nasal cavities 134
Pharynx 135
Larynx 136
Trachea 136
Bronchi 136
Lungs 137
Blood supply 137
Thoracic cavity 139
Respiratory muscles and their innervation 139
Inspiratory muscles 139
Expiratory muscles 139
Other respiratory muscles 139
Innervation 139
Functional peculiarities of the equine respiratory system at rest and adaptations during exercise 139
Ventilation 139
Lung volumes 139
Expired minute volume 139
Alveolar and dead space ventilation 142
Distribution of ventilation 143
Factors that tend to reduce ventilatory asynchrony 143
Factors that tend to increase ventilatory asynchrony 143
Pulmonary perfusion 144
Factors influencing pulmonary vascular resistance 144
Factors influencing pulmonary perfusion distribution 144
Gravitational factors 144
Humoral and neural factors 145
Hypoxic vasoconstriction 145
Bronchial circulation 145
Lymphatic circulation 145
Ventilation to perfusion ratio 145
Pulmonary diffusion 146
Composition of the respiratory gases 146
Alveolar diffusion 147
Tissue diffusion 148
Gas exchange 148
Oxygen uptake 148
Carbon dioxide output 148
Blood gas transport 149
Oxygen 149
Oxygen dissolved 149
Oxygen bound to hemoglobin 149
Oxygen content 149
Carbon dioxide 150
Mechanics of breathing 150
Breathing strategy in the horse 150
Pleural pressure 152
Pulmonary resistance 152
Definition and distribution throughout the respiratory system 152
Effect of exercise on total pulmonary resistance 152
Factors increasing resistance to air flow during exercise 152
Friction and turbulence 152
Dynamic partial collapse of the airways 153
Nonpathologic factors influencing pulmonary resistance 153
Dynamic compliance 153
Pulmonary inertance 153
Physiologic implications 154
Consequences for the measurement of the dynamic compliance 154
Mechanical work of breathing 154
Inspiratory muscles to total oxygen uptake ratio 154
Respiration locomotion coupling 155
Respiratory muscle recruitment 155
Control of breathing 156
Respiratory control at rest 156
Central control 156
Chemoreceptors and humoral control 156
Pulmonary and airway receptors 156
Muscle spindle stretch receptors 156
Respiratory control during exercise 156
Respiratory control during low-intensity exercise 157
Respiratory control during high-intensity short-term exercise 157
Hypotheses to explain the lack of compensatory hyperventilation in horses exercising intensely 157
Influence of the locomotion–respiration coupling on exertional ventilation 157
Lesser sensitivity of receptors 157
Influence of force–velocity characteristics of ventilatory muscles 157
Negative-feedback mechanisms generated by ventilatory muscle fatigue 157
A possible explanation for the lack of compensatory hyperventilation in horses performing intense exercise 158
Respiratory control during submaximal prolonged exercise 158
Respiratory function during recovery from exercise 159
Respiratory adaptations to training 159
Effect of training on gas exchange 159
Effect of training on ventilation 160
Effect of detraining 160
The respiratory system and its thermoregulatory role 160
The respiratory system and its role in acid–base homeostasis 160
Conclusion 161
Acknowledgments 161
References 161
10 Transport of horses 164
History of the transport of performance horses 164
Road 164
Air 164
Size of the present-day horse transport industry 164
Road 164
Air 165
Current methods of transport of athletic horses 165
Road 165
Air 165
Is the transport of horses stressful? 166
Potential stressors within the transport environment 166
Methods of assessment of stress 167
Manifestations of stress 167
Behavior and orientation in relation to the direction of movement during road transport 167
Changes in laboratory measurements in horses transported by road 167
Changes in laboratory measurements in horses transported by air 167
Effects on respiratory and enteric health status 168
Jet lag 168
Effects on subsequent performance 168
Management and veterinary care of horses in transit 168
Prior to transport 168
During transport 168
After transport 169
Treatment of shipping fever 169
Post-transport recovery period 169
References and suggested reading 170
11 The cardiovascular system: Anatomy, physiology, and adaptations to exercise and training 171
Anatomy and basic physiology 171
Cardiac cycle 171
Cardiovascular adaptations to exercise 172
Heart rate 172
Heart rate in the resting horse 172
Measurement of heart rate during exercise 173
Heart rate at the start of exercise 173
Heart rate during submaximal exercise 173
Maximal heart rate 174
Submaximal exercise heart rates and fitness measurements 175
Heart rate recovery after exercise 176
Heart rate and training 176
Oxygen pulse 177
Stroke volume and cardiac output 177
Blood pressure and vascular resistance 177
Systemic circulation 177
Pulmonary circulation 178
Blood pressure and training 179
Blood volume 179
Plasma volume 179
Effect of exercise on plasma volume 179
Effect of training on plasma volume 179
Plasma volume and diet 179
Plasma volume and athletic performance 180
Total red blood cell volume 180
Distribution of cardiac output 180
Conclusion 180
References 181
12 Muscle anatomy, physiology, and adaptations to exercise and training 183
Muscle structure and function 183
Muscle anatomy 183
Embryology 183
Muscle ultrastructure 184
Contractile proteins 184
Sarcomere 184
Thick myofilaments 184
Thin myofilaments 185
Cytoskeleton 185
Sarcolemma and sarcoplasmic reticulum 186
Muscle basement membrane 186
Sarcolemma 186
Neuromuscular junctions 186
Sarcoplasmic reticulum 187
Excitation–contraction coupling 187
Other organelles 187
Equine muscle composition: Response to exercise and adaptations with training 187
Muscle composition 187
Percutaneous muscle biopsy 188
Fiber types 189
Myosin–atpase differentiation 189
Immunohistochemical differentiation 189
Speed of contraction 189
Metabolic differentiation 190
Other features 191
Immunofluorescent and immunohistochemical stains 191
Fiber areas 191
Ultrastructural differentiation 191
Biochemical assays 192
Gene transcription 192
Fiber type populations within muscles 192
Muscle fiber recruitment 193
Response to exercise 193
Fatigue with high intensities of exercise 194
Lactate accumulation 195
Nucleotide depletion 196
Potassium 196
Glycogen 197
Muscle temperature 197
Effect of warmup 197
Fatigue with prolonged low-intensity (submaximal) exercise 197
Substrate depletion 197
Fat 198
Muscle glycogen 199
Blood glucose 199
Hyperthermia and electrolyte depletion 199
Central fatigue 199
Muscle adaptation: Effects of age and training 200
Changes in early life (growth) 200
Birth to 1 year 200
Metabolic changes 200
Contractile properties 200
Adaptations with training 200
Fiber type alterations 201
Fiber sizes 201
Capillarization 201
Metabolic changes 201
Oxidative enzymes 201
Glycolytic enzymes 202
Other enzymes 202
Nucleotides 202
Glycogen 202
Lipid and carnitine 202
Buffering capacity 202
Sarcolemma and sarcoplasmic reticulum 203
Muscle fiber recruitment 203
Detraining (relative inactivity) 203
Summary of training effects 203
Relationship of fiber type composition to performance 204
Limitations to performance created by metabolic myopathies 204
Mitochondrial myopathy 204
Disorders of lipid oxidation 205
Glycogen storage disorders 205
Glycogen branching enzyme deficiency (gbed) 206
Polysaccharide storage myopathy 206
Conclusion 208
References and suggested reading 208
13 Tendon, ligament, bone, and cartilage: Anatomy, physiology, and adaptations to exercise and training 211
Tendons and ligaments 212
Tendon and ligament anatomy and function 212
Anatomy of tendons and ligaments of the distal limb 212
Hierarchical structure, microanatomy, and matrix composition 213
Fascicles 213
Collagenous matrix 214
Noncollagenous matrix 215
Biomechanical properties of digital tendons and ligaments 217
Structural and material properties 217
Energy-storing versus positional tendons 218
Cellular basis of tendon and ligament matrix maintenance and response to exercise 219
Central role of the tenocyte 219
Cell types and networks 219
Tenocyte types 219
Tenocyte network 220
Tendon-specific and age-specific differences in tenocyte networks 222
Functional adaptation of tendon 222
Evidence of exercise-induced microdamage 222
Effects of training on equine digital tendons 225
Controlled treadmill exercise studies 225
Controlled racetrack exercise studies 226
Should foals be trained from soon after birth? 226
Bone 226
Equine skeletal anatomy and function 226
Macroscopic anatomy 227
Microanatomy and matrix composition 228
Cortical and cancellous bone 228
Bone matrix 230
Biomechanical properties 230
Structural and material properties 230
Bone strains in equine athletes 231
Bone mechanics at a microanatomic level 231
Cellular basis of bone matrix maintenance and responses to exercise 232
Osteoblasts, osteocytes, and osteoclasts 232
Modeling and remodeling at the cellular level 233
Cellular responses to mechanical strain 233
Bone remodeling unit 233
Functional adaptation of bone 234
Evidence of exercise-induced microdamage 234
Microcracking of cortical and cancellous bone 234
Microcracking and targeted remodeling 235
Does microcracking occur in equine bone? 235
Effects of training on equine bone 236
Controlled treadmill exercise studies 236
Controlled racetrack exercise studies 238
Should foals be trained from soon after birth? 239
Can training increase resistance to fractures? 239
Cartilage 240
Articular cartilage anatomy and function 240
Microanatomy and matrix composition 241
Collagenous matrix 241
Noncollagenous matrix 242
Biomechanical properties 242
Structural and material properties 242
Compressive, tensional, and shear loading 242
Mechanics at ultrastructural and molecular levels 243
Topographic variations 243
Cellular basis of cartilage matrix maintenance and responses to exercise 244
Chondrocytes 244
Cellular responses to the mechanical environment 244
Functional adaptation of articular cartilage 245
Evidence of exercise-induced microdamage 245
Effects of training on equine articular cartilage 246
Controlled treadmill exercise studies 246
Should foals be trained from soon after birth? 246
References and suggested reading 247
14 Age and disuse in athletes: Effects of detraining, spelling, injury, and age 252
Detraining and disuse 252
Effect of aging on exercise capacity 253
Aging-induced changes in respiratory function that may impact exercise 253
Age-related changes in the cardiovascular response to exercise 254
Age-related changes in thermoregulation and fluid and electrolyte balance 255
Effects of age on body composition and muscle fiber type 257
Aging-related alterations in the endocrine response to exercise 258
Alterations in the immune response to exercise 260
Renal, gastrointestinal, and other systems 260
Conclusion 260
References and suggested reading 260
III Biomechanics/kinematics and performance 262
15 Conformation 262
Assessment of conformation 262
Subjective assessment of conformation 264
Objective assessment of conformation 266
Neck and forelimb 267
Hindlimb 267
Photography or videography and digital photography 267
Motion systems 268
Influences on conformation 268
Genetic inheritance 268
Age 269
Sex 270
Breed and performance criteria 270
References 274
16 The biomechanics of equine locomotion 275
Biomechanical adaptations in equine anatomy 275
Locomotion analysis 276
Definition of biomechanical parameters 276
Systems for biomechanical measurement of parameters 276
Inverse dynamic analysis 276
Forward dynamic analysis 278
Kinematic analysis 278
Systems used for kinematic analysis of gait 279
Videography 279
Optoelectric systems 279
Kinetic analysis 280
Systems used to measure kinetic analysis of gait 280
Force plates 280
Pressure plate 282
Strain gauges 282
Instrumented horseshoes 282
Accelerometers 282
Electromyography 283
Treadmill evaluation of locomotion 284
Instrumented treadmills 284
Normal locomotion: Gait classification in horses 284
Symmetrical gaits 284
Walk 284
Trot 285
Pace 285
Asymmetrical gaits 285
Gallop 285
Canter 286
Gait transition 286
Interlimb coordination and the principles of neuromotor control 287
Neuromotor control 287
Sensorimotor system and peripheral joint function 288
Applications in horses 288
References 289
17 Kinematics of the equine back and pelvis 291
Biomechanical concept of the quadrupedal back 291
Research leading to current analytical techniques for equine thoracolumbar kinematics 293
Basic kinematics 294
Thoracolumbar motion in the horse 295
Sacroiliac motion 296
Applied research into the kinematics of the equine back and pelvis 297
Fundamental aspects of spinal motion and interaction with the appendicular skeleton 297
Basic kinematics 297
Back pain 297
Back pain and lameness 298
Assessment of the effects of therapeutic interventions on back motion 298
Use of equine spinal kinematics to assess performance or training techniques 299
Performance evaluation 299
Future developments 299
References 300
18 Functional biomechanics: Effect of the rider and tack 302
Effect of tack on the horse 302
Effect of saddle and saddle pads 302
Effect of reins and bridle 304
Effect of rider on the horse 304
Effect of body mass of the rider 305
Effect of riding technique 306
Effect of rider experience 306
Conclusion 307
References 307
IV Practical exercise physiology 308
19 Training regimens: Physiologic adaptations to training 308
Muscular responses to exercise 308
Enzymes in muscle 308
Aerobic enzymes 308
Glycolytic enzymes 308
Enzymes associated with purine nucleotide metabolism 308
Capillarity 309
Alterations in fiber types 309
Glycogen concentration 309
Buffering capacity 309
Hematologic responses to training 309
Hemogram 309
Plasma biochemistry 309
Blood and plasma volume 310
Changes in cardiorespiratory variables in response to training 310
Heart rate 310
Stroke volume and cardiac output 310
Maximal oxygen uptake (o2max) 310
Metabolic responses to training 310
Lactate production and metabolism 310
Application of indices of fitness to horses in training 310
Resting measurements 310
Conclusion 310
20 Training the thoroughbred racehorse 311
Phases of training 311
Phase 1: Endurance training 311
Phase 2: Combined aerobic and anaerobic training 312
Phase 3: Anaerobic training 313
Conclusion 313
21 Training standardbred trotters and pacers 314
Breaking yearlings 317
Alternative training methods: Use of resistance cart, heart rate monitor, and lactate analyzer 317
Advances in veterinary care 319
Advances in nutrition 320
Acknowledgements 322
References 322
22 Training endurance horses 323
Selection of endurance horses 323
Training for distance 323
Training the musculoskeletal system 324
Training energy systems in the muscle 325
Training the cardiovascular system 325
Training fluid and electrolyte systems 326
Training gastrointestinal systems 327
Mental training and cross-training 327
Training for veterinary inspections 328
Training for speed 328
Return to work after time off 329
Overtraining 329
Acknowledgements 329
References 329
23 Training the event horse 330
The sport of modern eventing 330
The modern event horse 330
Dressage, cross-country, and show jumping phases 330
Weighting of phases and scoring system 330
Fence characteristics and course distances 332
Short versus long format 332
Future direction and potential implications 332
Selecting the ideal horse 332
Conformation 332
Temperament 333
Breeding 333
Training the young horse 333
Starting the young event horse 333
Flat and jump training 333
Preparatory training days and competitions 334
The first event 334
Progression of the young event horse and training at the pre-novice and 1* level 334
The first season and progression through the grades 334
Flat and jump training 334
Conditioning and preliminary fitness training 335
Gps data in training versus competition in 1*- and pre-novice–level horses 335
Stretching, core strengthening, and dynamic stability exercises 335
Management of the young event horse 335
Training of the national level event horse at 2* and 3* level 336
Flat and jump training 336
Dressage and show jumping competitions 336
Fitness training 337
Gps data in training versus competition in 2*- and 3*-level horses 337
Planning the competition career 337
Maintaining soundness in the event horse 337
Training of the international event horse 338
Flat and jump training 338
Fitness training 338
Warmup for cci**** cross-country event 338
Gps data in training versus cci**** competition 339
Team training for international competition 339
Prolonging the career of the international event horse 339
References 339
24 Dressage tests, movements, and training: A primer 340
Breeds of horses used in dressage 340
Dressage arenas 340
Competition 342
Dressage tests 342
Scoring dressage tests 342
Scribing 342
Movements required in dressage tests 342
Basics of training the horse for dressage: The training scale 343
Rhythm and regularity (takt) 343
Relaxation (losgelassenheit) 343
Contact (anlehnung) 343
Impulsion (schwung) 344
Throughness (durchlässigkeit) 344
Straightness (geraderichtung) 344
Collection (versammlung) 344
Movements in classical dressage: “airs above the ground” 344
Conclusion 344
References 345
25 Training show jumpers 346
Conformation and show jumping 346
Biomechanics of show jumping 346
Approach 347
Take-off 347
Jump suspension 348
Landing 348
Move-off 348
Physiologic demands of show jumping 348
Predictability of jumping performance and the effect of early training on jumping ability 349
Training on the flat 350
Training over fences 351
Conditioning the show jumper 351
Cardiovascular conditioning 351
Strength training 352
Gradients 353
Gymnastic jumping 353
Suppling exercises 353
Dynamic suppling 353
Passive suppling 354
Other considerations 354
References and suggested reading 355
26 Training working horses 356
Profile of the working horse 356
Specific physiological requirements of training and competition 356
Musculoskeletal requirements 356
Stop and roll back 357
Motor skill acquisition 358
Injury profile of the working horse 359
Specific training regime 359
Injury prevention strategies 360
Selection of the horse for the purpose 360
Avoidance of overfeeding 361
Foot care 361
Arena surface 361
Training regime and rest periods 362
Specific injury-preventive exercises 362
Conclusion 362
References 362
27 Training the racing quarterhorse 363
Uniqueness of the racing quarterhorse 363
Distances 363
Speeds 363
Selection of horses 363
Example training program 363
Changes associated with training 366
Muscle 366
Skeleton 366
Tendon 366
Respiratory system 367
Mental conditioning 367
Management of horses in training 368
Nutrition 368
Common types of unsoundness 368
Shoes 368
Fulfilling genetic potential 369
References and suggested reading 369
28 Evaluation of performance potential 370
Athletic performance 370
Oxygen-transport chain 370
O2max 370
Airways and lungs 370
Cardiovascular system 371
Blood volume 371
Musculoskeletal system 371
Anaerobic energy delivery 371
Muscle power 371
Buffering capacity 372
Conformation 372
The intangibles 372
Concepts of fatigue 372
Fatigue in response to high-intensity exercise 373
Fatigue during prolonged submaximal exercise 373
Measurements for evaluation of performance potential 373
Estimation of heart size 373
Heart score 373
Echocardiography 374
Total red blood cell volume 374
Muscle biopsy 374
Exercise testing 374
Conclusion 374
29 Clinical exercise testing 375
Indications for exercise testing 375
Track versus treadmill exercise tests 375
Track exercise testing 376
Overview of testing procedures 377
Standardized track-based exercise test for standardbred trotters 378
Testing procedure 378
Calculation of indices of exercise capacity 378
Velocity and blood lactate concentration 378
Velocity and heart rate 378
Reproducibility 379
Interpretation of v4 and v200 379
V4, v200, and track testing 379
V4, v200, and state of training 379
V4, v200, and clinical usefulness 381
V4, v200, and respiratory disease 381
V4, v200, and orthopedic disease 381
Track exercise tests for horses undertaking other disciplines 383
Thoroughbreds 383
Event horses 383
Show jumping horses 383
Treadmill exercise tests 384
Incremental versus high-speed tests 384
Specific protocol for exercise testing 384
Measurements during a treadmill exercise test 384
Heart rate during exercise 384
Cardiovascular disease 385
Telemetric electrocardiography 385
Blood (plasma) lactate measurement 385
Arterial blood gas analysis during exercise 386
Endoscopic examination of the upper respiratory tract during exercise 386
Oxygen uptake 387
Conclusion 387
Index 388
A 388
B 389
C 390
D 391
E 392
F 394
G 394
H 395
I 396
J 396
K 397
L 397
M 397
N 399
O 399
P 399
Q 400
R 401
S 402
T 404
U 405
V 405
W 406
Y 406
Z 406