Dose-response effect of pre-exercise carbohydrates under muscle glycogen unavailability:Insights from McArdle disease  

作　　者：Pedro L.Valenzuela Alfredo Santalla Lidia B.Alejo Andrea Merlo Asuncion Bustos Laura Castellote-Belles Roser Ferrer-Costa Nicola A.Maffiuletti David Barranco-Gil Tomas Pinos Alejandro Lucia 

机构地区：[1]Physical Activity and Health Research Group(“PaHerg”),Research Institute of Hospital“12 de Octubre”(“imas12”),Madrid 28041,Spain [2]Department of Systems Biology,University of Alcala,Madrid 28871,Spain [3]Department of Sport and Computer Science,Section of Physical Education and Sports,Faculty of Sport,Universidad Pablo de Olavide,Sevilla 41013,Spain [4]EVOPRED Research Group,Universidad Europea de Canarias,Tenerife 38300,Spain [5]Faculty of Sport Sciences,Universidad Europea de Madrid,Madrid 28670,Spain [6]Gait&Motion Analysis Laboratory,Sol et Salus Hospital,Torre Pedrera di Rimini(RN)47922,Italy [7]Department of Clinical Biochemistry,Laboratoris Clınics,Hospital Universitari Vall d’Hebron,Barcelona 08035,Spain [8]Human Performance Lab,Schulthess Clinic,Zurich 8008,Switzerland [9]Biomedical Research Networking Center on Rare Disorders(CIBERER),Barcelona 08035,Spain [10]Mitochondrial and Neuromuscular Disorders Unit,Vall d’Hebron Institut de Recerca,Universitat Autonoma de Barcelona,Barcelona 08035,Spain

出　　处：《Journal of Sport and Health Science》2024年第3期398-408,共11页运动与健康科学（英文）

基　　金：supported by a Sara Borrell postdoctoral contract granted by Instituto de Salud Carlos III(CD21/00138).;PLV,DB-G and AL are funded by the Spanish Ministry of Economy and Competitiveness and Fondos Feder(Alejandro Lucia,Grant No.PI18/00139);TP is funded by the Spanish Ministry of Economy and Competitiveness and Fondos Feder(Tomas Pinos,Grant No.PI22/00201).

摘　　要：Background:This study aimed to determine the effect of different carbohydrate(CHO)doses on exercise capacity in patients with McArdle disease—the paradigm of“exercise intolerance”,characterized by complete muscle glycogen unavailability—and to determine whether higher exogenous glucose levels affect metabolic responses at the McArdle muscle cell(in vitro)level.Methods:Patients with McArdle disease(n=8)and healthy controls(n=9)underwent a 12-min submaximal cycling constant-load bout followed by a maximal ramp test 15 min after ingesting a non-caloric placebo.In a randomized,double-blinded,cross-over design,patients repeated the tests after consuming either 75 g or 150 g of CHO(glucose:fructose=2:1).Cardiorespiratory,biochemical,perceptual,and electromyographic(EMG)variables were assessed.Additionally,glucose uptake and lactate appearance were studied in vitro in wild-type and McArdle mouse myotubes cultured with increasing glucose concentrations(0.35,1.00,4.50,and 10.00 g/L).Results:Compared with controls,patients showed the“classical”second-wind phenomenon(after prior disproportionate tachycardia,myalgia,and excess electromyographic activity during submaximal exercise,all p<0.05)and an impaired endurance exercise capacity(-51%ventilatory threshold and55%peak power output,both p<0.001).Regardless of the CHO dose(p<0.05 for both doses compared with the placebo),CHO intake increased blood glucose and lactate levels,decreased fat oxidation rates,and attenuated the second wind in the patients.However,only the higher dose increased ventilatory threshold(+27%,p=0.010)and peak power output(+18%,p=0.007).In vitro analyses revealed no differences in lactate levels across glucose concentrations in wild-type myotubes,whereas a doseresponse effect was observed in McArdle myotubes.Conclusion:CHO intake exerts beneficial effects on exercise capacity in McArdle disease,a condition associated with total muscle glycogen unavailability.Some of these benefits are dose dependent.

关 键 词：ENDURANCE Glycogen storage disease GLYCOGENOSIS NUTRITION SUPPLEMENT 

分 类 号：R589[医药卫生—内分泌] G804.2[医药卫生—内科学]