CreatineDietary SupplementsAmidinotransferasesCreatine KinasePhosphocreatineWeight LiftingMuscle, SkeletalTennisDouble-Blind MethodImmobilizationAdministration, OralAdenosine TriphosphateMuscular AtrophyExercisePhysical EnduranceLactic AcidResistance TrainingEnergy MetabolismMuscle ProteinsGlycineOxygen ConsumptionCreatine Kinase, MM FormMuscle ContractionMagnetic Resonance SpectroscopyTreatment OutcomeCreatine Kinase, Mitochondrial FormFood, FortifiedCreatine Kinase, MB FormGuanidinoacetate N-MethyltransferaseAnimal FeedVitaminsIsoenzymesVitamin EVitamin ADietZincFolic AcidRandom AllocationClinical Enzyme Tests