Muscle FatigueFatigueMuscle, SkeletalMusclesMuscle ContractionElectromyographyIsometric ContractionFatigue Syndrome, ChronicMental FatigueMuscle Fibers, SkeletalQuadriceps MuscleRespiratory MusclesPhysical EnduranceMuscle ProteinsMuscle, SmoothAbdominal MusclesMuscle, Smooth, VascularTorqueBackMuscle DevelopmentExerciseElectric StimulationMuscle WeaknessNeck MusclesMuscle RelaxationMuscle StrengthPhysical ExertionDiaphragmIntercostal MusclesTime FactorsMuscle Fibers, Fast-TwitchBacteriophage muMuscle Fibers, Slow-TwitchElbowMuscle DenervationReceptors, Opioid, muLactic AcidMuscular DiseasesBiomechanical PhenomenaExercise ToleranceMitochondria, MuscleMyocytes, Smooth MuscleOculomotor MusclesBicyclingFemoral NerveMotor NeuronsElectric Stimulation TherapyExercise TestMuscle SpindlesOxygen ConsumptionInhalationMuscle, StriatedLumbosacral RegionMyographyLegRunningKneePapillary MusclesPhosphocreatineAdaptation, PhysiologicalLocomotionHand StrengthGlycogenProprioceptionCalciumIsotonic ContractionAnkle JointWeight-BearingMuscle CellsSpectroscopy, Near-InfraredLower ExtremityAnalysis of VarianceFacial MusclesHeliumMasseter MuscleMusculoskeletal SystemSignal Processing, Computer-AssistedMovementMasticatory MusclesMuscular AtrophySarcoplasmic ReticulumPostural BalanceTask Performance and AnalysisRegional Blood FlowRespiratory MechanicsUpper ExtremityRespirationSatellite Cells, Skeletal MuscleRats, WistarOxygenEnergy MetabolismPulmonary Disease, Chronic ObstructiveGaitExercise TherapyAnoxiaPectoralis MusclesPostureMotor CortexAction PotentialsIschemia