Effects of Caffeine on Muscle Glycogen Utilization and the Neuroendocrine Axis during Exercise1
Laurent D, Schneider K, Prusaczyk W, Franklin C, Vogel S, Krssak M, Petersen K, Goforth H, Shulman G. Effects of Caffeine on Muscle Glycogen Utilization and the Neuroendocrine Axis during Exercise1. The Journal Of Clinical Endocrinology & Metabolism 2000, 85: 2170-2175. PMID: 10852448, DOI: 10.1210/jcem.85.6.6655.Peer-Reviewed Original ResearchConceptsMuscle glycogen contentMuscle glycogen utilizationGlycogen contentCaffeine ingestionNeuroendocrine axisGlycogen utilizationGlycogen-sparing effectFree fatty acid concentrationsBeta-endorphin levelsCaffeine-treated groupExercise-induced glycogen depletionMaximal oxygen consumptionEffects of caffeineHigher muscle glycogen contentPlacebo groupExercise enduranceFatty acid concentrationsPlasma concentrationsNeuroendocrine hormonesCortisol releaseProlonged exerciseGlycogen depletionPlasma lactateNormal valuesThigh musclesGlycogen loading alters muscle glycogen resynthesis after exercise
Price T, Laurent D, Petersen K, Rothman D, Shulman G. Glycogen loading alters muscle glycogen resynthesis after exercise. Journal Of Applied Physiology 2000, 88: 698-704. PMID: 10658040, DOI: 10.1152/jappl.2000.88.2.698.Peer-Reviewed Original ResearchConceptsMaximum voluntary contractionGlycogen recoveryNOR trialMuscle glycogen resynthesisMuscle glycogen recoveryNormal resting levelsGlycogen resynthesisVoluntary contractionHeavy exercisePlantar flexionResting levelGlycogen concentrationGlycogen levelsSeparate occasionsSimilar glucoseUntrained subjectsTrialsGlycogen synthesisExerciseExtended recoverySubjectsRecoveryLevelsMinFlexion