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 g...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.展开更多
Background:The side effects of the FIFA 11+program on performance have not been generally reviewed.The objective of this study was to synthesize the literature on the effects of the 11+on players’performance.Methods:...Background:The side effects of the FIFA 11+program on performance have not been generally reviewed.The objective of this study was to synthesize the literature on the effects of the 11+on players’performance.Methods:Five online databases(PubMed,Scopus,ScienceDirect,Springer,and Google Scholar)were searched(from April 2006 to March 2022)using predefined keywords and sub-keywords.The potential references were primarily recorded through Endnote and imported to Covidence.Out of the 123 references screened by 2 blinded researchers through the software,59 full texts were assessed for eligibility,33 of which were ultimately included.The quality of the studies and the risk of bias were then assessed.Study ID,title,place,aim,design,start/end dates,population description,study criteria,statistical analysis,and outcomes were extracted.Results:Studies were conducted on male and female players aged 10-32 years old.The quality of the studies was moderate to high,and except for unclear bias for blinding outcome assessment,the risk of bias for all domains was low.Long-term application of the 11+improved most biomechanical measures and physiological responses except for lower extremity stability,ankle evertors time latency,ankle dorsiflexion,and proprioception.Conversely,the 11+showed acute negative effects on physical performance compared to dynamic warm-ups and non-significant effects on technical abilities.Conclusion:Mid-to-long-term implementation of the 11+improved the maj ority of biomechanical and a couple of physical measure s but showed no effects on technical skills.Precaution must be observed for using the 11+before competitions,as it could acutely decrease physical/technical performance.Given the contradictory nature of the literature,further studies should evaluate the short-to-mid-term effects of the 11+.Further studies are required to address ankle responses to the 11+intervention.展开更多
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).
文摘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.
文摘Background:The side effects of the FIFA 11+program on performance have not been generally reviewed.The objective of this study was to synthesize the literature on the effects of the 11+on players’performance.Methods:Five online databases(PubMed,Scopus,ScienceDirect,Springer,and Google Scholar)were searched(from April 2006 to March 2022)using predefined keywords and sub-keywords.The potential references were primarily recorded through Endnote and imported to Covidence.Out of the 123 references screened by 2 blinded researchers through the software,59 full texts were assessed for eligibility,33 of which were ultimately included.The quality of the studies and the risk of bias were then assessed.Study ID,title,place,aim,design,start/end dates,population description,study criteria,statistical analysis,and outcomes were extracted.Results:Studies were conducted on male and female players aged 10-32 years old.The quality of the studies was moderate to high,and except for unclear bias for blinding outcome assessment,the risk of bias for all domains was low.Long-term application of the 11+improved most biomechanical measures and physiological responses except for lower extremity stability,ankle evertors time latency,ankle dorsiflexion,and proprioception.Conversely,the 11+showed acute negative effects on physical performance compared to dynamic warm-ups and non-significant effects on technical abilities.Conclusion:Mid-to-long-term implementation of the 11+improved the maj ority of biomechanical and a couple of physical measure s but showed no effects on technical skills.Precaution must be observed for using the 11+before competitions,as it could acutely decrease physical/technical performance.Given the contradictory nature of the literature,further studies should evaluate the short-to-mid-term effects of the 11+.Further studies are required to address ankle responses to the 11+intervention.
