Endocrinology of Physical Activity and Sport (eBook)

Endocrinology of PhysicalActivity and Sport 4
PREFACE 6
CONTENTS 8
CONTRIBUTORS 10
1: Methodological Considerations in Exercise Endocrinology 13
Introduction 13
Physiological Factors 15
Sex 15
Age 15
Ethnicity and Race 16
Body Composition 16
Mental Health 17
Menstrual Cycle 17
Circadian Rhythms 18
Procedural-Analytical Factors 18
Ambient Environment 19
Nutrition 20
Nutrient Timing 20
Meal Frequency and Patterning 21
Disordered Eating 21
Stress-Sleep 22
Physical Activity 22
Subject Posture-Position 23
Specimen Collection 23
Analytical Assays 24
Data Transformations 25
Statistical Analysis 25
Summary and Conclusion 26
References 27
2: Exercise and Endogenous Opiates 32
Introduction (Endogenous Opiates) 32
In?uence of Acute Exercise on b E Levels 34
Aerobic Exercise at Various Work Intensities Related to % VO 2 Max (Aerobic Capacity) 34
High-Intensity Bouts with an Anaerobic Component 35
In?uence of Training on Beta-Endorphin Levels 36
In?uence of Endurance Training 36
In?uence of Resistance Training on circulating b E 37
b E and Immune system 37
Endogenous Opioids and Pain Perception 39
b E and Glucoregulation 40
In?uence of Acute Exercise on Enkephalins 41
Summary 43
References 44
3: The Effect of Exercise on the Hypothalamic–Pituitary–Adrenal Axis 48
Overview 48
The HPA Axis 49
The HPA Axis and Exercise 50
Endurance Training 50
Resistance Training 51
Intensity of Physical Activity and HPA Axis Activation 52
Highly Trained and Elite Athletes 52
Overtraining 53
Level of Fitness and Aging 53
Memory, Defeat, Fear, and Cognitive Functions 53
Voluntary Physical Activity and Aggressiveness 54
Conclusion 54
References 55
4: Impact of Chronic Training on Pituitary Hormone Secretion in the Human 59
Introduction 59
Multiple Determinants of Pituitary Responses to Exercise Training 61
Other Confounding Issues 64
Neuroendocrine Axes as Feedback and Feedforward Control Systems 67
Interactions Among Neuroendocrine Axes 68
Metabolic Mechanisms 69
Implications 70
Summary 70
References 71
5: Exercise and the GH–IGF-I Axis 78
Introduction 78
The GH–IGF-I Axis 79
Assessment of the Training Load 80
Optimizing Different Types of Training Modalities 81
Aerobic Training 81
Anaerobic Exercise 83
Recovery Modalities and the GH–IGF-I Axis 85
Nutrition, Performance, and the GH–IGF-I Axis 86
Preparation for Competition 87
References 89
6: Exercise and Thyroid Function 93
Introduction 93
Thyroid Physiology 94
Thyroid Hormone Effects 95
CARDIOVASCULAR EFFECTS OF THYROID HORMONES 96
In Vivo Animal Studies on the Role of Abnormal Thyroid Function in the Regulation of Cardiac Response to Exercise 97
Clinical Findings 97
Hypothyroidism 97
Hyperthyroidism 99
Effects on Systemic Vascular Resistance (SVR) 100
Clinical Findings 101
Hypothyroidism 101
Hyperthyroidism 101
Effects in Muscles 102
In Vivo Animal Studies on the Role of Abnormal Thyroid Function in the Regulation of Muscle Response to Exercise 102
Clinical Findings 103
Hypothyroidism 103
Hyperthyroidism 105
EFFECTS ON PULMONARY FUNCTION 107
Clinical Findings 107
Hypothyroidism 107
Hyperthyroidism 107
Exercise and Thyroid Axis Response 108
Summary 116
References 117
7: The Male Reproductive System, Exercise, and Training: Endocrine Adaptations 128
Introduction 128
Physiology of the Male Gonadal Axis 129
Effects of Physical Exercise on Testicular Steroidogenesis 130
Short, Intense Exercise Increases Circulating Testosterone 130
Mechanisms Underlying Increases in Circulating Testosterone Following Short, Intense Exercise 131
Prolonged, Submaximal Exercise and Chronic Exercise Training Decrease Circulating Testosterone 132
The “Exercise-Hypogonadal Male”: Clinical Issues 133
The “Exercise-Hypogonadal Male”: Pathophysiological Mechanisms 133
Effects of Physical Exercise on Spermatogenesis 135
Oxidative Stress as a Putative Mechanism Underlying Impaired Spermatogenesis in Exercise-Hypogonadal Men 135
References 136
8: Exercise and the Hypothalamus. Ovulatory Adaptations 140
Introduction 140
The Ovulatory Cycle 141
Terminology 141
Definitions 141
Imprecise Language About Reproduction 143
Physiology 143
Ovarian Hormone Levels During the Normal Cycle 143
Hormonal Profile Changes During Disturbed Cycles 144
Documentation of Ovulatory Function 145
Currently Used Indirect Methods 145
Limitations of Available Methods for Diagnosis of Ovulation Disturbances 145
Quantitative Basal Temperature 146
Hypothalamic Adaptation and Ovulatory Function 147
Hypothalamic Adaptive Processes 148
Stress Mechanism 149
Energy Conservation 151
Synergism or Interactions Among Factors In?uencing Ovulatory Function 151
Energy Balance 151
Eating Restraint 152
Hypothalamic Reproductive “Maturation” 153
Stress Intensity 154
Adaptations to Exercise Training 156
Exercise Training Studies in Mature Women 156
Observable Changes Prior to Ovulation Disturbances: Molimina 160
Time-Course of Ovulatory Adaptation 161
Reversibility/Adaptation 162
Clinical Applications/Treatment 167
Conclusions 167
References 169
9: Adrenergic Regulation of Energy Metabolism 174
Introduction 174
Adrenergic Responses to Acute Exercise 175
Motor Control and Re?ex In?uence on Adrenergic Response 176
Adrenergic Activity After Physical Training 176
Hepato-splanchnic Glucose Production and Adrenergic Activity 177
Adrenergic Effect on Skeletal Muscle Carbohydrate Metabolism 178
Sympathoadrenergic Activity and Fat Metabolism 178
Summary 179
References 179
10: Energy Balance and Weight Control (Male and Female): Considerations 182
Introduction to Energy Balance 182
Hormones Involved in Energy Balance, Fat Distribution, and Weight Control 183
In?uence of Physical Activity on Appetite and Energy Balance 187
Effects of Exercise on Hormones: Sex Differences 187
Summary 188
References 189
11: Exercise Training in the Normal Female: Effects of Low Energy Availability on Reproductive Function 191
The Female Athlete Triad 191
Hypothetical Mechanisms of Functional Hypothalamic Menstrual Disorders in Exercising Women 192
Body Composition 192
Energy Availability 193
Exercise Stress 194
Prospective Clinical Experiments 195
Experiments Confounding Exercise Stress and Energy Availability 195
Experiments Distinguishing the Independent Effects of Exercise Stress and Energy Availability 196
Excalibur I 197
Excalibur II 197
Excalibur III 197
Excalibur IV 200
Excalibur V 201
Excalibur VI 204
Conclusions About the Hypothetical Mechanisms of Functional Hypothalamic Amenorrhea in Female Athletes 204
Causes of Low Energy Availability in Female Athletes 205
Needed Research 206
References 207
12: Ghrelin Responses to Acute Exercise and Training 212
Introduction 212
Ghrelin During Growth and Maturation in Children 213
Ghrelin Relationships with Adiposity and Energy Availability 214
Ghrelin Responses to Acute Exercise 214
Chronic Exercise Training and Ghrelin Responses 217
Conclusions and Future Directions 220
References 221
13: Hormonal Regulation of Fluid and Electrolyte Homeostasis During Exercise 225
Introduction 225
Physiologic Responses to Exercise 226
Modulation of Hormones in Responses to Exercise 227
Workload Intensity 227
Exercise Duration 228
Training 228
Hydration Status 228
Sex 229
Health Status 229
Other In?uencing Factors 230
Hormone Responses to Exercise 230
Catecholamines 231
Vasopressin 231
Renin-Angiotensin-Aldosterone 233
Natriuretic Peptides 233
Atrial Natriuretic Peptide 234
Brain Natriuretic Peptide 235
Urodilatin 235
Adrenomedullin 235
Fluid and Electrolyte Regulation 236
Total Body Water 236
Sweating 237
Fluid and Electrolyte Intake 238
Renal Function 239
Renal Blood Flow 240
Glomerular Filtration Rate 240
Urine Flow Rate 240
Renal Handling of Electrolytes 241
Summary 241
References 242
14: Hormonal Regulations of the Effects of Exercise on Bone: Positive and Negative Effects 249
Introduction 249
Negative Effects of Exercise on Hormonal Regulation of Bone 250
Negative Effects of Exercise on Reproductive Hormone Status 250
Estrogen and Progesterone 250
Testosterone 252
Negative Effect of Exercise on Calciotropic Hormones 253
Negative Effects of Exercise on Parathyroid Hormone 253
Negative Effects of Exercise on Calcitonin and Vitamin D 254
Positive Effects of Exercise on Hormonal Regulation of Bone 254
Interactions Between Exercise and Estrogen for Increasing Bone Mass 254
Effects of Exercise on Anabolic Hormones 255
Acute Effects of Exercise on Anabolic Hormones and Bone Metabolism 255
Effects of Exercise Training on Anabolic Hormones and Bone Mass 256
Positive Effects of Exercise on Calciotrophic Hormones 257
Parathyroid Hormone 257
Calcitonin and Vitamin D 258
Directions for Future Research 258
Summary 259
References 259
15: Interrelations Between Acute and Chronic Exercise Stress and the Immune and Endocrine Systems 263
Introduction 263
Mechanisms of Interaction: In Vitro Evidence 265
Stress Hormones and Leukocyte Mobilisation In Vivo 266
Stress Hormones and Leukocyte Function In Vivo 267
Immunoendocrine Responses to Acute Exercise 268
Correlations Between Stress Hormones and Immunological Variables 268
Exercise Workload, Stress Hormones and Immunological Variables 269
Carbohydrate Supplementation, Stress Hormones and Immunological Variables 270
Caffeine Supplementation, Stress Hormones and Immunological Variables 271
Thermal Stress, Stress Hormones and Immunological Variables 271
Drugs, Stress Hormones and Immunological Variables 272
Evidence for Interactions Between the Central Nervous and Immune Systems 273
Chronic Interactions Between the Endocrine and Immune Systems 274
Biological Significance of Interactions Between the Endocrine and Immune Systems 275
Summary 276
References 276
16: Effects of Female Reproductive Hormones on Sports Performance 285
Introduction 285
Physiology of the Menstrual Cycle 286
Oral Contraceptives 287
Physiological Effects of the Female Sex Steroid Hormones 289
Cardiovascular Function 289
Respiratory Function 290
Substrate Metabolism and Energy Sources 290
Body Composition, Weight, and Bone Mineral Density 292
Thermoregulation 293
Psychological Factors: Estrogen and the Brain 293
Female Reproductive Hormones and Athletic Performance 294
Cardiovascular Function and Athletic Performance 295
Cardiovascular Function and the Menstrual Cycle 295
Oral Contraceptives and Cardiovascular Function 295
Respiratory Function and Athletic Performance 296
Respiratory Function and the Menstrual Cycle 296
Oral Contraceptives and Respiratory Function 297
Substrate Metabolism 298
Thermoregulation 299
Physical Capacity, Strength, and Reproductive Hormones 301
Physical Capacity, Strength, and the Menstrual Cycle 301
Oral Contraceptives and Strength 302
Aerobic Capacity and Reproductive Hormones 303
Aerobic Capacity and the Menstrual Cycle 303
Oral Contraceptives and Aerobic Capacity 303
Anaerobic Capacity and Reproductive Hormones 304
Anaerobic Capacity and the Menstrual Cycle 304
Oral Contraceptives and Anaerobic Capacity 305
Female Reproductive Hormones and Overall Sport Performance 306
Menstrual Cycle and Overall Sport Performance 306
Oral Contraceptives and Overall Sport Performance 307
Female Reproductive Hormones and Sports Injuries 308
ACL Injuries 308
Summary 311
References 311
17: Exercise and Pregnancy: Hormonal Considerations 327
Introduction 327
Hypothalamus 328
Corticotropin-Releasing Hormone 328
Pituitary 328
Growth Hormone (GH) 328
Thyroid-Stimulating Hormone 329
Adrenocorticotropic Hormone 329
Prolactin 330
Vasopressin or Antidiuretic Hormone 330
Endorphins (B-Endorphin) 330
Adrenals 331
Cortisol 331
Epinephrine 331
Norepinephrine 332
Estrogens and Progesterone 333
Pancreas 333
Insulin 333
Glucagon 333
Adipose Tissue 334
Leptin 334
Thyroid 335
Triiodothyronine (T3) and Thyroxine (T4) 335
Parathyroid 335
Parathyroid Hormone 335
Liver 336
Vitamin D 336
Placenta 336
Estrogens 337
Progesterone 337
Insulin-Like Growth Factors 1 and 2 337
Human Chorionic Gonadotropin 338
Placental Growth Hormone 338
Human Placental Lactogen 338
Relaxin 338
Summary 339
References 339
18: Vitamin D and Exercise Performance 343
Introduction 343
Physiology of Vitamin D 345
Vitamin D, Calcium Regulation, and Bone Health 345
Additional Roles of Vitamin D 347
Vitamin D Synthesis and Metabolism 348
Cutaneous Synthesis 349
Dietary Intake of Vitamin D 350
Vitamin D -Binding Protein 350
Vitamin D Receptor 351
Methods of Measurement and Optimal Concentrations 352
Vitamin D and Immunity 353
Hypovitaminosis D 355
Vitamin D Receptor and Skeletal Muscle 356
Vitamin D and Sarcopenia 358
Vitamin D and Exercise Performance 360
Summary 361
References 361
19: The Effects of Altitude on the Hormonal Response to Physical Exercise 367
Introduction 367
Growth Hormone/Insulin-Like Growth Factor-I Axis 368
Prolactin 370
Thyroid Function 371
Gonadal Function 373
Sympathoadrenal System 375
Hypothalamus–Pituitary–Adrenal Axis 376
Antidiuretic Hormone 378
Renin–Angiotensin–Aldosterone System 379
Hormonal Modulation of Energy Balance at High Altitude 380
Conclusions 381
References 381
20: An Introduction to Circadian Endocrine Physiology: Implications for Exercise and Sports Performance 389
Introduction 389
Biological Rhythms 390
Neuroanatomy of the Body Clock 390
Diurnal and Circadian Variation in Common Hormones 391
Melatonin 391
Cortisol 391
Prolactin 391
Testosterone 392
Measurements in Circadian Physiology 393
Constant Routine 393
Forced Desynchrony 393
Dim Light Melatonin Onset 394
Core Body Temperature 395
Morningness–Eveningness Questionnaire 395
Sleep 395
Interaction Between Circadian Rhythms and the Sleep Homeostat 396
Circadian Rhythms and General Human Performance 397
Circadian Rhythms and Athletic Performance 399
Effect of Exercise on Circadian Rhythms 400
Shift Work and Exercise 401
Circadian Effect of Light 402
Conclusions 403
References 405
21: Physical Activity and Mood. The Endocrine Connection 409
Introduction 409
Physical Activity Causes Mood Changes 409
Mood Assessment: The Profile of Mood Scores 410
Physical Activity, Hormones, and Mood 411
Hormones Can Cause Mood Changes 411
Thyroid Hormone 411
Cortisol 411
The Reproductive Hormones 412
Insulin 412
Leptin 413
b E and Mood: From POMC to POMS 413
Biological Roles of b E 413
b E Levels and Mood Changes 414
Monoamine Neurotransmitters 415
Noradrenaline (NA) and Dopamine (DA) 415
Serotonin (5-HT) 416
Summary 416
References 417
22: Endocrine Responses to Acute and Chronic Exercise in the Developing Child 420
Introduction 420
Acute Hormonal Responses to Aerobic Exercise 421
Catecholamine 421
Insulin 421
Glucagon 422
Cortisol 423
Growth Hormone and Insulin-Like Growth Factor Axis 424
Reproductive Hormones 425
Leptin 425
Acute Hormonal Responses to Anaerobic Exercise 425
Catecholamine 425
Cortisol 426
GH 426
Testosterone 427
The Role of Adiposity as a Modifying Factor of the Hormonal Responses to Exercise 427
Chronic Changes in Hormones with Exercise Training 429
General Responses 429
Insulin 430
Cortisol 430
GH-IGF-1 Axis 430
Sex Hormones 431
Leptin 432
Resistance Training 433
Insulin 433
Cortisol, GH, and Testosterone 433
Summary and Future Directions 434
References 436
23: Exercise in Older Adults: The Effect of Age on Exercise Endocrinology 440
The Aging Endocrine System 441
Menopause and Andropause 441
Adrenopause 443
Somatopause 443
Hormones and Health in Older Adults 444
Physical Activity and Endocrine Function in Older Adults 446
Physical Activity and Sex Steroids 446
Physical Activity and the GH/IGF-I System 448
Acute Exercise-Induced Hormone Responses in Older Adults 451
Significance of Exercise-Induced Hormone Responses in Older Adults 454
References 456
24: Oncology Patients and Aerobic Exercise: Immune System, Endocrine System, and Soluble Factor Responses 464
Introduction 464
Aerobic Exercise as an Intervention for Oncology Patients 466
Aerobic Exercise and Its In?uence on the Immune System of Oncology Patients 469
Immune Responses to Acute Aerobic Exercise 469
Immune Responses to Aerobic Exercise Training 471
During Cancer Treatment 471
After Cancer Treatment 477
Aerobic Exercise and Its In?uence on the Endocrine System and Soluble Factor Responses in Oncology Patients 484
Endocrine and Soluble Factor Responses to Acute Aerobic Exercise 484
Endocrine and Soluble Factor Responses to Aerobic Exercise Training 485
During Treatment 485
After Treatment 491
Future Research Directions 498
Conclusion 500
References 501
25: Diabetes and Exercise 504
Type 1 Diabetes and Sport 504
Type 2 Diabetes and Exercise 508
Mitochondrial Dysfunction 508
Exercise Prescription 509
Multidisciplinary Lifestyle Intervention 510
References 512
26: Extreme Sports and Type 1 Diabetes Mellitus: An Oxymoron or a Growing Reality? 515
Introduction 515
Glucose Homeostasis During Physical Activity and the Hurdle of Type 1 Diabetes 516
Type 1 Diabetes and Extreme Sports in Practice: The Evidence 517
Extreme Endurance Events: The Marathon Paradigm 518
Endurance Events in Extreme Topographic and Atmospheric Conditions: The Case of Mountaineering 518
Scuba Diving in Type 1 Diabetes: Allowed But Safe? 519
Extreme Sports and Type 2 Diabetes Mellitus? 521
Conclusions 522
References 523
27: The Endocrine System in Overtraining 525
Introduction 525
Endocrine Function and the Overtraining Syndrome 528
Other Hypothesized Mechanisms of the Overtraining Syndrome 531
Training Considerations to Prevent the Overtraining Syndrome 532
References 534
28: Hormones as Performance-Enhancing Agents 537
Introduction 537
Insulin 538
Physiology 538
Rationale 538
Performance Enhancement 538
Adverse Events 539
Detection 539
Human Growth Hormone 539
Physiology 539
Rationale 540
Performance Enhancement 540
Adverse Events 540
Detection 541
Insulin-Like Growth Factor I 541
Physiology 541
Rationale 541
Performance Enhancement 542
Adverse Events 542
Detection 542
Erythropoietin 542
Physiology 542
Rationale 543
Performance Enhancement 543
Adverse Events 543
Detection 543
Anabolic Steroids 544
Physiology 544
Rationale 544
Performance Enhancement 544
Adverse Events 545
Detection 545
Epilogue 545
Gene Doping 545
Summary and Future 546
References 546
Index 549