Muscle FatigueIsometric ContractionFatigueMuscle, SkeletalMuscle ContractionElbowElectromyographyMusclesMuscle StrengthKnee JointBiomechanical PhenomenaExercise TherapyMuscle Fibers, SkeletalFatigue Syndrome, ChronicMental FatigueQuadriceps MuscleTime FactorsPhysical EnduranceRange of Motion, ArticularTorqueMuscle, SmoothRespiratory MusclesMuscle ProteinsAbdominal MusclesMuscle, Smooth, VascularElectric StimulationExerciseMuscle RelaxationMuscle WeaknessBackNeck MusclesMuscle DevelopmentPhysical ExertionIsotonic ContractionDiaphragmMuscle Fibers, Fast-TwitchMuscle Fibers, Slow-TwitchIntercostal MusclesKneeMuscle DenervationHand StrengthPapillary MusclesMotor NeuronsMyographyLactic AcidMuscular DiseasesExercise ToleranceMuscle SpindlesLegMitochondria, MuscleMyocytes, Smooth MuscleFemoral NerveElectric Stimulation TherapyExercise TestCalciumBicyclingLumbosacral RegionPhosphocreatineOxygen ConsumptionOculomotor MusclesAnkle JointMuscle, StriatedMovementWeight-BearingAdaptation, PhysiologicalRunningPsoas MusclesInhalationLocomotionProprioceptionLower ExtremityAnalysis of VarianceSarcomeresGlycogenMuscular AtrophySpectroscopy, Near-InfraredMasseter MuscleMuscle CellsMasticatory MusclesRegional Blood FlowSarcoplasmic ReticulumTask Performance and AnalysisRabbitsAdenosine TriphosphateEnergy MetabolismSignal Processing, Computer-AssistedPostural BalanceHeliumMotor CortexRats, WistarFacial MusclesHindlimbMusculoskeletal SystemRana temporariaUpper ExtremityPostureMuscle Strength DynamometerGaitModels, BiologicalPhosphates