Exercise TestBicyclingExercisePhysical ExertionExercise ToleranceOxygen ConsumptionExercise TherapyHeart RateHead Protective DevicesRestPulmonary Gas ExchangeHemodynamicsAngina PectorisElectrocardiographyCardiac OutputPhysical EnduranceBlood PressureMuscle, SkeletalSupine PositionAnaerobic ThresholdStroke VolumeLactic AcidPhysical FitnessHeart FailureCoronary DiseaseEchocardiography, DopplerAsthma, Exercise-InducedTime FactorsEchocardiography, StressLegHeartVentricular Function, LeftDouble-Blind MethodErgometrySportsAdrenergic beta-AntagonistsVascular ResistanceEchocardiographyCraniocerebral TraumaRegional Blood FlowHeart VentriclesCoronary CirculationReference ValuesCoronary AngiographyBlood Flow VelocityRespirationRespiratory Function TestsDyspneaRunningReproducibility of ResultsWalkingLactatesOxygen