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 musclesMechanism of muscle glycogen autoregulation in humans
Laurent D, Hundal R, Dresner A, Price T, Vogel S, Petersen K, Shulman G. Mechanism of muscle glycogen autoregulation in humans. AJP Endocrinology And Metabolism 2000, 278: e663-e668. PMID: 10751200, DOI: 10.1152/ajpendo.2000.278.4.e663.Peer-Reviewed Original ResearchConceptsInsulin-stimulated ratesWhole body glucose oxidation ratesMuscle glycogenGlycogen loadingPlasma free fatty acid concentrationsWhole-body glucose uptakeFree fatty acid concentrationsMuscle glycogen contentGlucose oxidation ratesMuscle glycogen synthesisPlasma lactate concentrationTwofold increaseHyperinsulinemic clampGlycogen synthase activityFatty acid concentrationsLoading protocolGlucose infusionHealthy volunteersLactate concentrationGlycogen contentGlucose uptakeAnaerobic glycolysisGlycogen synthesisUnlabeled glucose infusionGlycogen