Study On Limiting Factors And Predictive Equations Of Maximal Oxygen Uptake Of Athletes At Different Levels

Purpose:The influencing factors of maximal oxygen uptake(VO2max)mainly include respiration,blood,cardiovascular and skeletal muscle.This paper compares the VO2max of athletes of different genders and different levels and the differences in various system indicators,explores the main limiting factors of VO2max,and establishes a mathematical model for predicting VO2max.Methods:A total of 151 students and athletes from Beijing Sport University,competitive sports school,national triathlon and cross-country skiers are recruited.They are grouped according to the following three methods:① Divided into M group(male,n=96)and F group(female,n=55)according to gender.②Divided into six groups according to the absolute value of VO2max and different genders,MJD(male with low absolute value,n=13),MJZ(male with medium absolute value,n=65),MJG(male with high absolute value,n=18),FJD(female with low absolute value,n=11),FJZ(female with medium absolute value,n=36)and FJG(female with high absolute value,n=8).③ Divided into six groups according to the relative value of VO2max and different genders,MXD(male with low relative value,n=13),MXZ(male with medium relative value,n=65),MXG(male with high relative value,n=18),FXD(female with low relative value,n=11),FXZ(female with median relative value,n=36)and FXG(female with high relative value,n=8).VO2max is tested by incremental load test,and modified CO inhalation method is used to test total blood indicators,and echocardiography is used to test cardiac structure and function indicators,and NIRS is used to test muscle oxygen.Using correlation test linear relationship between VO2max of athletes of different genders and various indicators.Using factor analysis and multiple regression analysis restriction on VO2max of athletes of different genders,and establishing the prediction model on VO2max.Results:①In all groups,the indexes highly related to the absolute value of VO2max are maximal voluntary ventilation(MVV),and some indexes of body composition,and total hemoglobin(tHb),while no indexes are highly correlated with the relative value of VO2max.②The trunk muscle mass of the M group is highly positively correlated with the absolute value of VO2max,and the body fat rate is highly negatively correlated with the relative value of VO2max,while there is no index in the F group that is highly correlated with VO2max.③After grouping according to the absolute value of VO2max,there are significantly related indicators as follows.In the MJD group,the left ventricular end-diastolic diameter(LVIDd),body fat rate(Fat%)and relative value of tHb are highly correlated.In the MJZ group,MVV,muscle mass,transferrin(Trf),hemoglobin concentration([Hb])and the relative value of total hemoglobin([tHb])are highly correlated.In the MJG group,the vital capacity(VC),cardiac output(CO),Deff and tHb are highly correlated.In the FJD group,the left ventricular end-systolic diameter(LVIDs),CO,Deff,muscle mass,serum Ferritin(Fe),[Hb]and tHb are highly correlated.In the FJZ group,VC,MVV,ejection fraction(EF%),Deff,muscle mass,[Hb]and tHb are highly correlated.In the FJG group,VC,Deff,muscle mass,Trf,total iron binding capacity(TIBC),[Hb]and[tHb]are highly correlated.④The correlations between the groups grouped according to the relative value of VO2max and the four major system indicators are similar to the absolute value,but there are also subtle differences.Conclusion:①Overall,the VO2max of all athletes is closely related to MVV,muscle mass and tHb.②The central system(oxygen transport)is a common factor that limits the VO2max of athletes of different genders and different levels,and the peripheral system(oxygen utilization)is the main limiting factor of VO2max for middle and high-level female athletes.③Considering the athletes’ cardiopulmonary function,the ability of muscles to use oxygen,body composition,blood and other factors,six VO2max predictive regression equations are established according to different genders and different levels.The explanatory degrees are all greater than 85%and p<0.05,and predictive indicators are representative and practical.