Exercise TestPhysical FitnessOxygen ConsumptionPhysical ExertionExerciseHeart RatePhysical Conditioning, AnimalExercise TherapyExercise ToleranceRunningPhysical EnduranceMuscle, SkeletalWalkingIntermittent ClaudicationRestAsthma, Exercise-InducedElectrocardiographyHemodynamicsPulmonary Gas ExchangeBlood PressureTime FactorsAnaerobic ThresholdAngina PectorisCardiovascular Physiological PhenomenaMotor ActivityCoronary DiseaseHeat ExhaustionLactic AcidGaitGait Disorders, NeurologicLegCoronary CirculationRegional Blood FlowCardiac OutputDogsAdaptation, PhysiologicalRespirationGlycogenEnergy MetabolismAnalysis of VarianceWeight-BearingHindlimbCitrate (si)-SynthaseEchocardiography, StressHeartMyocardial IschemiaOxygenBody WeightBicyclingLocomotionRecovery of FunctionLactatesDouble-Blind MethodBed RestHeart FailureStroke VolumePeripheral Vascular DiseasesHeart Function TestsPropranololHyperventilationEchocardiographyDyspneaPulmonary VentilationDipyridamoleNitroglycerinPredictive Value of TestsCarbon DioxideResistance TrainingThallium RadioisotopesBiomechanical PhenomenaCross-Over StudiesHorsesAdrenergic beta-AntagonistsMuscle ContractionVasodilator AgentsLower Body Negative PressureTreatment OutcomeFollow-Up StudiesBlood GlucoseProspective StudiesLower ExtremityAgingWeightlessnessRespiratory Function TestsTomography, Emission-Computed, Single-PhotonRespiratory Physiological PhenomenaParesisPosturePhysical Education and TrainingChronic DiseaseVentricular Function, LeftPulmonary CirculationVascular ResistanceMyocardial ContractionVasodilationElectrocardiography, AmbulatoryTidal VolumeEpinephrineMuscle Stretching ExercisesRats, Sprague-Dawley