Altitude SicknessMuscle FatigueAltitudeAnoxiaFatigueMuscle, SkeletalMusclesMuscle ContractionCell HypoxiaIsometric ContractionMuscle ProteinsElectromyographyFatigue Syndrome, ChronicMyocardiumMuscle Fibers, SkeletalMental FatigueHeartMyocytes, CardiacPhysical EnduranceMountaineeringQuadriceps MuscleMuscle, SmoothRespiratory MusclesAbdominal MusclesMuscle, Smooth, VascularPapillary MusclesTime FactorsMuscle DevelopmentExerciseMyocardial ContractionElectric StimulationOxygenAcclimatizationTorqueBackCalciumPhysical ExertionCardiac OutputMuscle RelaxationOxygen ConsumptionMuscle WeaknessNeck MusclesMuscle StrengthDiaphragmMuscle Fibers, Fast-TwitchAdaptation, PhysiologicalMyofibrilsHypoxia, BrainMuscle Fibers, Slow-TwitchSarcomeresIntercostal MusclesLactic AcidMuscular DiseasesHeart VentriclesSarcoplasmic ReticulumArrhythmias, CardiacRespirationBiomechanical PhenomenaMitochondria, MuscleExercise ToleranceElbowRabbitsMuscle DenervationExercise TestTibetFetal HypoxiaMyocytes, Smooth MuscleBicyclingRats, WistarRats, Sprague-DawleyCells, CulturedTroponin CRunningAtmospheric PressureCardiac Surgical ProceduresMuscle CellsTroponinCardiomegalyHeart RateDeath, Sudden, CardiacTroponin IAnalysis of VarianceEnergy MetabolismPhosphocreatineHypoxia-Inducible Factor 1, alpha SubunitOculomotor MusclesRNA, MessengerGlycogenAction PotentialsInhalationFemoral NerveRespiratory MechanicsElectric Stimulation TherapyLegCardiac MyosinsMyosin Heavy ChainsMotor NeuronsAdenosine TriphosphateMuscle, StriatedDogs