PhosphocreatineMagnetic Resonance SpectroscopyCreatineSubstance PAdenosine TriphosphateEnergy MetabolismPhosphatesPhosphorus IsotopesCreatine KinasePhosphorusMuscle, SkeletalAdenosine DiphosphateCreatine Kinase, BB FormLactatesCreatine Kinase, MM FormLactic AcidHydrogen-Ion ConcentrationOxygen ConsumptionCreatine Kinase, Mitochondrial FormOxidative PhosphorylationGlycolysisMusclesMitochondria, MuscleSubstance-Related DisordersMyocardiumMuscle ContractionExerciseGuanidinoacetate N-MethyltransferaseGlycogenAdenine NucleotidesAspartic AcidBrainHypoxia, BrainMuscle FatigueAdenosine MonophosphateInosine MonophosphateKineticsRats, Inbred StrainsDichloroacetic AcidPerfusionReceptors, Neurokinin-1Physical ExertionSubstance Abuse Treatment CentersPhosphorus CompoundsErgometryCholinePhysical Conditioning, HumanTime FactorsOxygenBrain ChemistryIodoacetic AcidMyocardial ContractionAcidosisAcetylcarnitineGlycerylphosphorylcholineGlucoseIodoacetatesIsometric ContractionHeartPerhexilinePyruvate Dehydrogenase ComplexRestProtonsMagnetic Resonance ImagingPropionatesPyruvic AcidDinitrofluorobenzeneMitochondria, HeartLegPhysical EndurancePyruvatesRats, WistarAmidinotransferasesAnoxiaAdenylate KinaseThiobarbituric Acid Reactive SubstancesBrain IschemiaHumic SubstancesRats, Sprague-DawleyReference ValuesHazardous SubstancesQuadriceps MuscleGuinea PigsSwineInositolModels, Biological2,4-Dinitrophenol