摘要：Subm aximal training can induce adaptiv e chang es in the ske letal muscles,cardiovascular system,respiratory system,endocrine system,and the like.Knowledge of the ad ap tatio n's signs a nd m agn itude,the factors causing it,as well a s aw are ness of the significance of th e ad ap tatio n for the imp rov ement of phy sica l capacity to exercise is essential to developing an optim al training programme a nd by a n adequate recovery pro cess to achieving maxim um positive effect at minim um negative effect on the athlete's health.Body adap tat ion resultin g from reg ula r aerobic training can involve enhancem ent of muscle enzyme system s,changes in muscle fibre type s and v asc ula risation,metabolic changes in the tra ined mu scle gro ups related to glucose,glycogen an d fat utilisation as sourc es of energy.Fur thermore,chang es in the blood,the immu ne an d coagulatio n status of the body accompany changes in pa rameters relate d to the aerobic working capacity of the organism.Regular sub ma xim al exercises have been found to inc rea se the activity of key oxidative enzymes in the metabolic pathway for the breakdown of carbohydrat es - hex okinas e (HK) and citrate synthase (CS) an d fats - 3-hydroxyacyl-CoA dehydrogenase (3-HAD) and carnitin e palmitoyltransferase (CPT) a nd in th e respiratory chain citochrome c oxidase (CCO).Subm aximal training ind uces vascu larisation in the mu scl es containing pre dominantly oxidative muscle fibres,and also enhanc es fibre type tra nsfor ma tion.Ins ulin-m ediate d glucose tra ns po rt in the cells of the rec rui ted mu scl es is selectively increased.A metabolic ad ap tatio n occur s as the body shifts from using carbo hydra tes for energy to using fats;the su bse quent,'glycogen-sparing"effect e nh ances physical working capacity.Perm anent changes occur in humoral immunity,evidenced by the increase of serum IgA and IgG concentrations.The blood oxygen tran sport system a dju sts itself to a more economical operation.As a final result,both the external oxygen delivery and the mitochon drial oxygen uti lisation syste ms und erg o adaptat ion lead ing to a moderate inc rea se in max imal oxygen c onsum ption,bu t to a gre ate r in cre ase in run ning economy.
关键词：Submaximal exercise;adaptation;athletes;aerobic working capacity
