Muscle and Exercise Physiology

Front Cover......Page 1
Muscle and Exercise Physiology......Page 4
Copyright Page......Page 5
Dedication......Page 6
Contents......Page 8
List of Contributors......Page 18
Preface......Page 22
I. Skeletal Muscle Morphology......Page 24
1.2 The Assessment of the System as a Whole......Page 26
1.2.1 Body Mass, Basal Metabolic Rate, and Total Daily Energy Expenditure......Page 27
1.2.2 Body Mass Index......Page 28
1.2.3 Body Circumferences and Skinfolds Measurements......Page 29
1.2.4 Body Surface Area......Page 30
1.2.5 Body Volume and Body Density......Page 31
1.3.1.2 Total Body Potassium......Page 32
1.3.2.1 Total Body Water......Page 33
1.3.2.4 Total Body Mineral......Page 35
1.3.3.1 Extracelullar Fluid......Page 36
1.3.3.3 Body Cell Mass......Page 37
1.3.4 Body Composition at the Tissue–Organ Level......Page 38
1.3.4.2 Skeletal Muscle Tissue......Page 39
1.4 Basics of Body Compartmentalization......Page 42
1.4.1 Two-Compartment Model of Body Composition......Page 43
References......Page 44
2.2 Muscle Fibers, Basic Morphological and Physiological Units......Page 50
2.2.1 Microscopic Structure of Muscle Fibers......Page 51
2.2.2.1 A Bands......Page 53
2.2.2.3 Z line......Page 54
2.4 The Capillary Network of the Muscle Fibers......Page 55
2.5 Sarcoplasmic Reticulum......Page 58
2.6 Proteins of the Sarcoplasmic Reticulum Membranes......Page 59
References......Page 60
3.1 Introduction......Page 62
3.2 The Motor—Myosin......Page 63
3.4.1 The Cross-Bridge Cycle......Page 65
3.5 The Sensor......Page 67
3.7.1 Force-Frequency Relationship and Recruitment......Page 69
3.8 Relaxation......Page 70
References......Page 71
4.2.1 The Motor Unit......Page 74
4.2.3 Classification of Motor Units......Page 76
4.2.4 Variability in the Contractile Properties of Motor Units......Page 77
4.3.1 Location, Morphology, and Innervation......Page 80
4.3.2 Motoneuron Excitability—Diversity of Motoneurons of S, FR, and FF Motor Units......Page 83
4.3.3 Rhythmic Firing of Motoneurons—Bistability and Adaptation......Page 85
4.3.4 Synaptic Input to Motoneurons......Page 87
4.4 Recruitment of Motor Units......Page 88
4.4.1 Henneman’s Size Principle......Page 89
4.5.1 The Force–Frequency Relationship......Page 90
4.5.2 Force Modulation by the Pattern of Motoneuronal Firing......Page 95
4.6 Motor Unit Action Potentials......Page 97
4.7 Differences in Motor Unit Properties Between Muscles......Page 99
4.8 Interspecies Differences in Motor Units......Page 100
4.10 Plasticity of Motor Units......Page 102
4.10.1 Plasticity of Motor Unit Contractile Properties......Page 103
4.10.2 Plasticity of Motoneurons......Page 104
4.11.1 Muscle Spindles......Page 106
4.11.2 Tendon Organs......Page 108
4.12.1 Electrophysiological Investigation of Functionally Isolated Motor Units......Page 109
References......Page 110
II. Muscle Energetics and Its Performance......Page 116
5.2.3 Metabolic Regulation......Page 118
5.3 Noninvasive Access to Skeletal Muscle Metabolism......Page 119
5.4.2 13C MRS Measurement of TCA Cycle Flux......Page 120
5.4.3.1 ATP Supply and Demand......Page 121
5.4.3.3 Feedback Regulation and Its Limits......Page 122
5.5 Interpreting 31P MRS Data: Measurements in Muscle at Rest......Page 123
5.7 Interpreting 31P MRS Data: Exercise Responses......Page 124
5.7.3 “Oxidative” Exercise, Where Glycolytic ATP Synthesis Can Be Ignored......Page 125
5.7.4 Recovery From Exercise: Studying Mitochondrial Function......Page 126
5.7.5 Recovery From Exercise: Studying Proton Efflux......Page 127
5.7.6 High Intensity Exercise: Glycolytic and Oxidative ATP Synthesis......Page 128
5.8.3 Combining NIRS and 31P MRS......Page 129
References......Page 130
6.2.1 Biochemical Changes in Response to Contractile Activity......Page 134
6.3 Thermodynamics of Muscle Contraction......Page 135
6.3.2.1 Initial Enthalpy Output From PCr Breakdown......Page 136
6.3.2.2 Recovery Enthalpy Output From Substrate Oxidation......Page 137
6.4.1.1 Initial Mechanical Efficiency......Page 138
6.4.1.2 Efficiency Depends on Shortening Velocity or Force Opposing Shortening......Page 139
6.4.1.4 Problems With Expressing Efficiency in Terms of Initial Enthalpy Output......Page 140
6.4.1.6 Effect of Fiber Type on Cross-Bridge Thermodynamic Efficiency......Page 141
6.4.1.8 What Limits Cross-Bridge Thermodynamic Efficiency?......Page 142
6.4.2.1 Estimates From ηCB and Empirical Recovery/Initial Enthalpy Ratio......Page 143
6.4.2.2 Direct Measurements of Overall Efficiency......Page 144
6.5.1 Data From Isolated Human Muscle Fibers......Page 145
6.5.2.3 Estimating Cross-Bridge Thermodynamic Efficiency for Human Muscle......Page 146
6.6 Conclusion......Page 147
References......Page 148
Appendix 6.1......Page 149
Appendix 6.2......Page 150
7.2 Muscle Activation......Page 152
7.2.2 Muscle Fiber Types......Page 153
7.2.3 Contractile Properties......Page 155
7.2.4 Motor Unit Activation......Page 156
7.3.1 Sarcomere......Page 158
7.3.2 Muscle Fiber Length......Page 159
7.3.3 Muscle Fiber Anatomy......Page 160
7.4 Muscle Function......Page 161
7.4.1.1 Assessment......Page 162
7.4.1.2 Voluntary Activation......Page 164
7.4.1.3 Stretch-Shorten Cycle......Page 165
7.4.1.4 Training Adaptations......Page 167
7.4.2.2 Voluntary Activation......Page 168
7.4.2.3 Speed-Related Adaptations......Page 170
7.4.3 Fatigability......Page 171
7.4.3.1 Fatigue Taxonomy......Page 172
7.4.3.2 Task Dependency......Page 173
References......Page 176
8.2 Historical Bases for the Critical Power Concept......Page 182
8.3 The Critical Power Concept: Mechanistic Bases......Page 186
8.3.1 Inspiratory Hyperoxia......Page 188
8.3.3 Inspiratory Hypoxia: Chronic......Page 189
8.3.4 Impact of Duty Cycle on Critical Power......Page 190
8.3.7 All-Out Maximal Exercise......Page 191
8.4 Application of the Critical Power Concept to All-Out Exercise (Whole Body, Limb, Muscle Group, Isolated Muscle)......Page 192
8.5.1.1 Training......Page 194
8.5.1.2 Competition......Page 195
8.5.3 Why Measure Critical Power and Wʹ as a Guide for Assessing Exercise Tolerance?......Page 196
8.7 Challenges to the Critical Power Concept......Page 198
8.8 Conclusions......Page 199
References......Page 200
9.1 Introduction......Page 206
9.3 Walking and Running......Page 207
9.3.1.2 Locomotion Pathologies......Page 211
9.3.1.3 Body Mass and Age......Page 212
9.3.2 Accelerated/Decelerated Running......Page 214
9.5.1 Mechanical Work and Energy Cost......Page 216
9.5.2 The Efficiency of Cycling......Page 218
9.5.4.1 On Size and Shape......Page 219
9.5.5 Altitude and Performance......Page 220
9.5.5.1 One-Hour Record for Unaccompanied Cycling......Page 222
9.5.6 On Sloping Grounds......Page 223
9.5.6.1 Metabolic Power and Body Mass......Page 224
9.6 Cross-Country Skiing......Page 225
9.7 Locomotion in Water......Page 226
9.7.1.1 “Good” and “Bad” Swimmers and Different Styles......Page 227
9.7.1.2 Of Men and Women......Page 228
9.7.2 The Biomechanics of Swimming: Hydrodynamic Drag and Efficiency......Page 229
9.7.3.1 Energy Cost......Page 231
9.7.3.2 Hydrodynamic Resistance and Efficiency......Page 232
References......Page 234
III. Muscle Metabolism and Exercise Physiology......Page 238
10.1.1 Introduction to Exercise Bioenergetics......Page 240
10.2.1 Exercise Intensity Domains......Page 242
10.2.2 Ramp-Incremental Exercise......Page 243
10.2.2.2 The “V-Slope” Relationship......Page 244
10.2.2.3 Maximum Oxygen Uptake (V̇O2max)......Page 247
10.2.2.4 Determinants of Maximum Oxygen Uptake (V̇O2max)......Page 248
10.2.3 Constant Power Exercise and V̇O2 Kinetics......Page 249
10.2.3.1 Moderate-Intensity V̇O2p Kinetics......Page 250
10.2.3.2 Heavy, Very-Heavy, and Severe-Intensity V̇O2p Kinetics......Page 251
10.3.1 Oxygen Stores......Page 253
10.3.3 Flow-Weighted Venous Admixture......Page 254
10.4.1 Evidence From Computer Simulation......Page 255
10.4.2 Evidence From Direct Measurement......Page 256
10.4.3 Kinetic Control of Muscle V̇O2......Page 257
10.4.3.1 Feedback Control by Intramuscular Phosphates......Page 258
10.4.3.3 Limitation by Skeletal Muscle Oxygenation......Page 260
10.4.3.4 Role of Oxidative Enzyme Activation......Page 262
10.5.2 Chronic Heart Failure......Page 263
10.5.3 Chronic Obstructive Pulmonary Disease......Page 264
References......Page 265
11.1 Introduction......Page 274
11.2 Overview of Carbohydrate Storage......Page 275
11.3 Regulation of Carbohydrate Metabolism......Page 276
11.3.1 Effects of Exercise Intensity and Duration......Page 277
11.3.2 Effects of Substrate Availability......Page 279
11.3.3 Effects of Training Status......Page 280
11.4.1 Muscle Glycogen and Carbohydrate Loading......Page 281
11.4.3 Carbohydrate Feeding During exercise......Page 282
11.5.1 Overview of Molecular Regulation of Training Adaptations......Page 283
11.5.2 Fasted Training......Page 284
11.5.5 Sleep-Low/Train-Low Models......Page 285
11.5.6 High-Fat Feeding......Page 286
11.5.7 Muscle Glycogen Threshold......Page 287
11.6 Conclusions......Page 289
References......Page 290
12.1.1 Trafficking of LCFA Across Sarcolemma......Page 294
12.1.3 Mechanisms of FA Transporters Translocation......Page 296
12.2.1 Glycerophospholipids......Page 297
12.2.3 Triacylglycerol lipases......Page 299
12.3.1 Metabolism of Sphingolipids......Page 300
12.3.4 Sphingosine-1-Phosphate and Skeletal Muscle Regeneration......Page 301
12.4.1 Triacylglycerols......Page 302
12.5 Conclusions......Page 303
References......Page 304
13.2 History: Myokines......Page 308
13.4.1.2 Exercise and Systemic Levels of Interleukin-6......Page 310
13.4.1.3 Interleukin-6 is an Energy Sensor......Page 312
13.4.1.4 Interleukin-6: A Role in Glucose and Lipid Metabolism......Page 313
13.4.3 Brain-Derived Neurotrophic Factor......Page 314
13.4.5 Interleukin-8......Page 316
13.4.6 Interleukin-15......Page 317
13.4.7 Leukemia Inhibitory Factor......Page 318
13.4.8 Irisin......Page 319
13.5.2 Follistatin-Like 1......Page 320
13.7 Myokine Screening......Page 321
References......Page 323
14.2 Differentiation of Fiber Types and Biogenesis of Mitochondria......Page 332
14.3 Muscle Contraction and Reactive Oxygen and Nitrogen Species......Page 333
14.4 RONS-Associated Oxidative Damage and Repair......Page 335
14.5 Conclusions......Page 336
References......Page 337
15.2.2 Effects With Strenuous Training/in Athletes......Page 340
15.3 Etiology of Upper Respiratory Illness......Page 342
15.4.1 Moderate Exercise......Page 344
15.4.2.1.1 Leukocyte Count Changes and Acute Exercise......Page 345
15.4.2.1.2 Innate Immune Cell Function and Acute Exercise......Page 346
15.4.2.1.3 Acquired Immune Cell Function and Acute Exercise......Page 348
15.4.2.1.4 Mucosal Immunity and Acute Exercise......Page 350
15.4.3 Exercise Training and Immune Function......Page 354
15.4.3.1 In Vitro and Ex Vivo Markers: Moderate Exercise......Page 355
15.4.3.2.1 Strenuous or Intensive Exercise......Page 356
15.5 Conclusions......Page 357
References......Page 358
IV. Body Adaptation to Exercise......Page 368
16.2.2 Fast- and Slow-Type Muscle: Connecting a Functional Link of the Muscle Fiber to Its Motor Neuron......Page 370
16.2.3 The Contributions of Archibald Vivian Hill to Fundamental Muscle Contraction Processes......Page 373
16.3.2 The Early Science of Muscle Plasticity: Adaptive Responses of Muscle Fibers to Simulated Physical Activity......Page 374
16.3.3 Early Studies on Exercise-Induced Adaptations in Skeletal Muscle......Page 375
16.4.2.1 Animal Studies......Page 376
16.4.3.1 Animal Studies......Page 377
16.4.4 Can Fast-Type Fibers Become Converted Into Slow-Type Fibers by Physical Activity Paradigms?......Page 378
16.5.1 Advancing Biotechnologies and Identification of the Myosin Heavy Chain Gene Family......Page 379
16.5.3 Functional Properties of the Myosin Heavy Chain Isoforms......Page 381
16.5.4.3 Resistance Exercise as a Countermeasure to Limb Unloading......Page 382
16.5.5 Single-Fiber Myosin Heavy Chain Polymorphism: How Many Patterns and the Role of Loading Conditions......Page 383
16.6.2.1 Supporting Evidence......Page 384
16.6.3.1 Protein Synthesis Alterations......Page 386
16.6.4 Mechanisms of Mitochondrial Biosynthesis Regulation Muscle Performance......Page 387
16.6.5.1 Approaches in Studying Gene Transcription in Response to Altered Activity Paradigms......Page 388
16.6.5.3 Calcineurin Signaling and Slow Myosin Heavy Chain Gene During Altered Activity Patterns......Page 389
16.6.6 Epigenetics and Muscle Gene Regulation in Response Unloading and to Exercise......Page 390
16.6.7 Role of Noncoding Antisense RNA During Altered Loading States......Page 391
16.6.9 Mechanisms of Mitochondrial Biogenesis and Degradation......Page 392
16.7 Conclusions......Page 393
References......Page 394
17.1 Introduction......Page 402
17.2 Anatomy and Functional Organization of the Skeletal Muscle Vasculature......Page 403
17.4 Interaction Between Metabolic and Sympathetic Control of Muscle Blood Flow......Page 404
17.5 Muscle Blood Flow Heterogeneity......Page 405
17.6 Impact of Exercise Training on Skeletal Muscle Blood Flow......Page 406
17.8 Impact of Exercise Training on Skeletal Muscle Capillarization......Page 408
17.9 Effects of Exercise Training on Skeletal Muscle Vascular Control......Page 409
References......Page 410
18.1 Introduction......Page 414
18.2 The Oxygen Uptake–Power Output Relationship......Page 416
18.3.1 Overall V̇O2 Kinetics......Page 419
18.3.2 Three Phases of Pulmonary V̇O2 Responses......Page 421
18.4.1 Primary Component of the Pulmonary V̇O2 On-Kinetics......Page 422
18.4.2 The Slow Component of Pulmonary V̇O2 On-Kinetics......Page 423
18.6.1 Oxygen Deficit......Page 424
18.6.2 The Rate of Adjustment of the V̇O2 On-Kinetics and the Size of the O2 Deficit: What Do They Tell Us?......Page 425
18.6.3 Oxygen Debt or the Excess Postexercise Oxygen Consumption......Page 426
18.6.5 V̇O2 Off-Kinetics: Other Approaches......Page 428
18.7.2 The Slow Component of the V̇O2 On-Kinetics......Page 429
18.8.1 Endurance Training and Muscle Metabolic Stability......Page 431
18.8.2 Endurance Training and the V̇O2 On-Kinetics......Page 432
18.8.3.1 Intensification of Mitochondrial Biogenesis......Page 433
18.8.3.2 Oxygen Delivery......Page 434
18.8.3.4 Intensification of Parallel Activation......Page 435
18.8.4 The Effect of Physical Training on the Slow Component of the Pulmonary V̇O2 On-Kinetics......Page 436
References......Page 438
19.2 Muscle Ageing and Daily Life Activities......Page 446
19.4.1 Age-Related Loss of Muscle Mass......Page 447
19.4.6 Neural Control......Page 448
19.6 Muscle Wasting and Function: Causes and Mechanisms......Page 449
19.6.1.2 Denervation–Reinnervation......Page 450
19.6.2 Mechanisms of Muscle Weakness......Page 451
References......Page 452
20.1 Introduction......Page 456
20.2.1.1 Short Excursion I; Basics: Bone Physiology......Page 458
20.2.1.2 Relevance of Bone Strengthening Versus Fall-, Fall-Impact Reduction......Page 459
20.2.3 Step Three: Defining the Most Relevant Primary Aims(s) of the Exercise Protocol......Page 460
20.2.4.1.1 Evidence for Exercise-Induced Fall Reduction......Page 461
20.2.4.1.3 Exercise Effects on Fall Impact......Page 462
20.2.4.2.2 Evidence for Exercise Effects on Bone Mineral Density......Page 463
20.2.4.3.2 Osteoanabolic Effect of Different Sports......Page 464
20.2.4.4.2 Strain Magnitude......Page 465
20.2.4.4.3 Strain rate......Page 466
20.2.4.4.4 Cycle Number, Repetitions......Page 467
20.2.4.4.7 Strain Density......Page 468
20.2.4.5 Considerations of Basis Principals of Exercise Training......Page 469
20.2.5 Step Five: Validation of Training Aims; Reappraisal......Page 470
References......Page 471
V. Heart Muscle and Exercise......Page 480
21.2 Morphology of the Cardiac Myocyte and its Contractile Machinery......Page 482
21.3 The Lateral Plasma Membrane and Transverse Tubules......Page 483
21.5 Intercellular Junctions Linking Cardiomyocytes......Page 484
21.6 Intermediate Filaments, Costameres, and the Plasma Membrane Skeleton......Page 487
21.8 Conclusions......Page 488
References......Page 489
22.2.1 Myocardial O2 Demand......Page 490
22.2.2.2 Oxygen Carrying Capacity of Arterial Blood......Page 491
22.2.2.3 Myocardial O2 Extraction......Page 492
22.2.3.1 Effective Perfusion Pressure......Page 493
22.2.4.1 Systolic Compression of Intramyocardial Vessels......Page 495
22.2.4.2 Subendocardial/Subepicardial Blood Flow Ratio......Page 496
22.2.4.3 Influence of Vasomotor Tone on the Transmural Distribution of Myocardial Blood Flow......Page 497
22.2.5 Coronary Blood Flow to the Right Ventricle......Page 498
22.2.6.1 Autonomic Nervous System......Page 499
22.2.6.3 Endothelium-Derived Vasoactive Factors......Page 503
22.2.6.4 Metabolic Messengers......Page 506
22.2.6.5 End-Effectors: K+-Channels......Page 507
22.2.6.6 Integration of Coronary Vasodilator Mechanisms During Exercise......Page 509
22.2.7 Epicardial Coronary Arteries......Page 510
22.2.8 The Coronary Circulation in Acute Exercise: Summary and Conclusions......Page 511
22.3.1 Structural Vascular Adaptations in the Heart......Page 512
22.3.2.2 Exercise Training and Vascular Control in the Coronary Microcirculation......Page 514
Acknowledgments......Page 515
References......Page 516
23.2 Cardiac Thermodynamics......Page 528
23.2.2 Heat Production......Page 529
23.2.4 Thermodynamic Efficiency and Entropy Creation......Page 530
23.2.8 Cross-Bridge Efficiency......Page 531
23.3.2 Ex Vivo Measurement of Cardiac Energetics......Page 532
23.3.2.1 Exercise Simulated in the Ex Vivo Rat Heart......Page 533
23.3.2.2 The Virtue of Varying Afterload......Page 534
23.3.3 In Vitro Measurement of Cardiac Energetics......Page 535
23.3.3.1 Additional Experimental Considerations......Page 538
23.3.3.1.2 Avoidance of Anoxia In Vitro......Page 539
23.3.4 “Total” Versus “Mechanical” Versus “Cross-Bridge” Efficiency......Page 540
23.3.5 Stress-length Area and Stress-Time Integral: Their Energetic Equivalence......Page 541
23.4.1 Basal Metabolism......Page 542
23.4.1.2 Influence of Metabolic Substrate......Page 543
23.4.2.1 The Heat–Stress Relation......Page 544
23.4.2.3 The V≐̸O2–PVA Relation......Page 545
23.4.3 Cross-Bridge Heat......Page 546
23.5.3 Cross-Bridge Cycling......Page 548
23.5.5 Model Details......Page 549
23.5.7 In Silico Simulation of Exercise......Page 550
23.6 Effect of Acute Exercise on Global Cardiac Energetics......Page 553
23.6.2 Activation Metabolism......Page 554
23.7 Conclusions......Page 555
References......Page 556
24.2 Static Exercise......Page 564
24.2.1 Onset of exercise......Page 565
24.2.2 Sustained Static Exercise......Page 569
24.2.3 Central Command Versus the Exercise Pressor Reflex......Page 570
24.2.5 Arterial Baroreceptors......Page 572
24.2.6 Standing......Page 573
24.3.1 Onset of Exercise......Page 574
24.3.2 Sustained (Steady-State) Exercise......Page 575
24.3.4 Central Command Versus the Exercise Pressor Reflex......Page 576
24.3.5 Autonomic Control of Heart Rate and Blood Pressure......Page 578
References......Page 579
25.1 Introduction......Page 584
25.2.1 Exercise Intolerance in Chronic Heart Failure......Page 585
25.2.3 Skeletal Muscle Atrophy and the Ubiquitin Proteasome System......Page 586
25.4.1 Neural Control Mechanisms During Exercise......Page 587
25.5.1 The Exercise Pressor Reflex in Chronic Heart Failure......Page 589
25.6.1 Effect of Exercise Training on the Exercise Pressor Reflex in Health......Page 591
25.6.2 Effect of Exercise Training on the Exercise Pressor Reflex in Chronic Heart Failure and Hypertension......Page 592
25.7 Mechanisms Underlying the Beneficial Effect of Exercise Training on the Exaggerated Exercise Pressor Reflex in Chronic.........Page 593
25.7.3 The TRPV1 Receptors Are Involved in the Mechanism by Which Exercise Training Prevents the Desensitization of Group I.........Page 594
25.7.4 Other Potential Mechanisms......Page 595
References......Page 597
Index......Page 604
Back Cover......Page 619