PhosphocreatineEnergy MetabolismMagnetic Resonance SpectroscopyCreatineAdenosine TriphosphatePhosphatesCreatine KinasePhosphorus IsotopesPhosphorusEnergy IntakeMuscle, SkeletalLactatesAdenosine DiphosphateCreatine Kinase, BB FormLactic AcidEnergy TransferCreatine Kinase, MM FormOxygen ConsumptionHydrogen-Ion ConcentrationGlycolysisOxidative PhosphorylationCreatine Kinase, Mitochondrial FormMusclesMitochondria, MuscleExerciseMyocardiumMuscle ContractionGlycogenGuanidinoacetate N-MethyltransferaseAdenine NucleotidesAspartic AcidBrainKineticsHypoxia, BrainMuscle FatigueAdenosine MonophosphatePhysical ExertionInosine MonophosphateGlucoseDichloroacetic AcidOxygenErgometryPerfusionTime FactorsPhosphorus CompoundsRats, Inbred StrainsCholineIodoacetic AcidPhysical Conditioning, HumanFluorescence Resonance Energy TransferThermodynamicsBrain ChemistryRestMyocardial ContractionProtonsIodoacetatesAcetylcarnitineAcidosisHeartPyruvic AcidGlycerylphosphorylcholineIsometric ContractionModels, BiologicalAdenylate KinasePyruvate Dehydrogenase ComplexPerhexilineMitochondria, HeartPropionatesConservation of Energy ResourcesPyruvatesSolar EnergyPhysical EnduranceDinitrofluorobenzeneMagnetic Resonance ImagingLegAnoxiaAmidinotransferasesMitochondriaOxidation-ReductionSwineRats, WistarBrain IschemiaBody WeightAnaerobiosisRenewable Energy2,4-DinitrophenolReference ValuesQuadriceps MuscleCell RespirationCitric Acid CycleInositolCarbon Dioxide