Creatine supplementation strategies aimed at acutely increasing and maintaining skeletal muscle total creatine content in healthy,young volunteers  

作　　者：George Pittas Jan Miller David Laithwaite Paul Greenhaff 

机构地区：[1]David Greenfield Human Physiology Unit,School of Life Sciences,University of Nottingham Medical School,Queen’s Medical Centre,Nottingham,UK

出　　处：《Translational Exercise Biomedicine》2024年第3期223-235,共13页运动转化生物医学(英文)

基　　金：This study was supported by the Iovate Health Sciences Research Inc.

摘　　要：Objectives Insight regarding dietary creatine(Cr)supplementation strategies to acutely increase and maintain muscle total creatine(TCr)content is missing.Methods Healthy,young,men ingested 4×5 g Cr/day(d)for 5d,followed by 5 g/d for 28 d(Cr group,n=8).To achieve insulin mediated muscle Cr transport,another group(n=16)ingested 4×5 g Cr plus 95 g dextrose/d for 5d(CrCHO),and thereafter two sub-groups ingested 5 g of Cr(CrCHO1,n=8)or 5 g Cr plus 95 g dextrose/d for 28 d(CrCHO2,n=8).A fourth group ingested 4×5g of Cr plus 14 g protein,7 g phenylalanine,7 g leucine and 57 g dextrose/d for 5 d,and once/d thereafter for 28 d(CrPAC,n=8).Muscle biopsies were obtained at 0,and after 5 and 33 d.Results After 5 d,muscle TCr increased in Cr(p<0.001),CrCHO(p<0.001),and CrPAC(p<0.05)groups,and was numerically greatest in CrCHO;achieving a content reported to be an average maximum(150 mmol/kg).After 33 d,TCr also increased to~150 mmol/kg in the Cr group(p<0.05),remained unchanged from 5 d in CrCHO2,and tended to decline in CrCHO1.Muscle TCr remained unchanged from 5 d in CrPAC after 33 d,being less than the Cr group(p<0.05).Muscle Cr transporter mRNA expression changed modestly,but the increase in muscle TCr after 5 d was inversely associated with fold-change in mRNA expression(r=0.502,p<0.05).Conclusions A maximum increase in muscle TCr is achieved after 5 d Cr ingestion alongside 95 g dextrose,and continued consumption of Cr with dextrose will maintain this maximum.Ingestion of Cr alone will achieve a high muscle TCr content too,but takes longer.

关 键 词：exercise nutrition dietary supplements INSULIN DEXTROSE 

分 类 号：R73[医药卫生—肿瘤]