Physical EnduranceAthletesAthletic PerformanceSportsSports MedicineDoping in SportsAthletic InjuriesRunningRacquet SportsPhysical Education and TrainingPhysical Conditioning, AnimalExerciseTrack and FieldBicyclingMuscle, SkeletalSports EquipmentPhysical FitnessOxygen ConsumptionPhysical ExertionMuscle FatiguePerformance-Enhancing SubstancesExercise TestSoccerCitrate (si)-SynthaseMuscle StrengthSnow SportsAnaerobic ThresholdExercise TherapyExercise ToleranceSkiingFootballAdaptation, PhysiologicalSwimmingBasketballResistance TrainingLactic AcidRespiratory MusclesWeight LiftingEnergy MetabolismMitochondria, MuscleGlycogenJoggingMusculoskeletal Physiological PhenomenaMartial ArtsIsometric ContractionFitness CentersQuadriceps MuscleTennisKnee InjuriesMotor ActivityMuscle ContractionHeart RateSprains and StrainsTime FactorsBreathing ExercisesBrain ConcussionAltitudeLeg InjuriesGymnasticsHockeyRestMaximal Voluntary Ventilation