Heart RateExercise TestPhysical ExertionPropanolaminesBetaxololExerciseHeartXamoterolAtenololAcebutololPropranololOxprenololAdrenergic beta-AntagonistsExercise TherapyMetoprololExercise ToleranceOxygen ConsumptionPindololHemodynamicsBlood PressureHeart FailureDouble-Blind MethodPhysical EnduranceHeart DiseasesMuscle, SkeletalHeart TransplantationHeart Defects, CongenitalRestTime FactorsFetal HeartBicyclingPhysical FitnessHeart ValvesResistance TrainingRunningAnaerobic ThresholdLactic AcidPulmonary Gas ExchangeHeart AtriaMuscle Stretching ExercisesHeart Function TestsHeart BlockMyocardiumCoronary DiseaseStroke VolumeMyocardial ContractionBreathing ExercisesTreatment OutcomeEnergy MetabolismVentricular Function, LeftRegional Blood FlowPhysical Education and TrainingLegGlycogenAdaptation, PhysiologicalHeart Arrest, InducedRespirationEchocardiographyCardiac Output, LowCardiovascular Physiological PhenomenaAsthma, Exercise-InducedOxygenExercise Movement TechniquesFollow-Up StudiesRisk FactorsProspective StudiesChronic DiseaseMuscle StrengthMuscle FatigueWeight LiftingMyocytes, CardiacVentricular Dysfunction, LeftSportsMyocardial InfarctionMyocardial IschemiaWalkingBlood GlucoseMuscle ContractionDyspneaCardiac OutputBody WeightSympathetic Nervous SystemLactatesMotor ActivityCardiomyopathy, DilatedCross-Over StudiesPhosphocreatineDogsHeart Failure, SystolicAgingErgometryCardiotonic AgentsAnalysis of VarianceAutonomic Nervous SystemReference ValuesRats, WistarQuadriceps MuscleCardiomegalyVascular ResistanceRats, Sprague-Dawley