Study On Predicting Maximum Oxygen Uptake Of College Students Based On Ambulatory Cardiopulmonary Function Indicators

ObjectiveTo investigate the correlation between dynamic cardiorespiratory fitness indexes and maximum oxygen uptake during incremental exercise,explore the physiological mechanisms,screen the indexes for assessing aerobic exercise capacity,establish a mathematical model for predicting maximum oxygen uptake in college students based on dynamic cardiorespiratory fitness indexes,and provide a theoretical and experimental basis for scientific fitness.MethodsThe subjects were 266 healthy university students(134 males and 132 females),200 in the modeling group and 66 in the validation group.The German Cortex Metalyzer 3B system and the American Cheetah NICOM system were used to monitor gas metabolism and heart function,and the maximum oxygen intake was measured through the linear load incremental motion scheme.The statistical data were analyzed using SPSS26.0,and the correlation coefficients were expressed as"mean±standard deviation",the correlation coefficient was expressed in r,and the level of salience was expressed in P.The K-S test was used to test the normal distribution of the data in each group,and the difference between the groups was tested by one-way ANOVA for the indicators that were normally distributed in all four groups,and the non-parametric Kruskal-Wallis test was used for the comparison between multiple groups for the indicators that did not conform to the normal distribution.Pearson and Spearman tests were used to test the linear and nonlinear correlation of each index with maximum oxygen uptake.The indicators associated with maximum oxygen uptake were further screened using biased correlation to control for influencing factors.Multiple linear stepwise regression was then used to find representative indicators that could predict maximum oxygen uptake in college students,and a mathematical model for predicting maximum oxygen uptake based on dynamic cardiopulmonary function indicators was established and the established equations were tested for goodness-of-fit and backgeneration.Result1.Dynamic cardiopulmonary function indexes such as K,b,SVmax,and SVImax were significantly different among college students with different exercise backgrounds and genders(P<0.01).Within the exercise group,SVmax,SVImax,SVmax-HR,(SVmax-HR/HRR)%were higher in males than in females,while K and b were lower than in females(P<0.05).Within the general group,K,b,SVmax,SVImax,SVmax-HR,(SVmax-HR/HRR)%were higher in males than in females(P<0.05).K,b,SVmax-HR,(SVmax-HR/HRR)%were lower in exercising males than in regular males,while SVmax and SVImax were higher than in regular males(P<0.05).K,b,SVmax-HR,(SVmax-HR/HRR)%were lower in exercising females than in regular females;while SVmax,SVImax were higher than in regular females(P<0.05).2.Pearson and Spearman correlation analysis revealed that K,b,SVmax,SVImax and VO₂max,VO₂max/kg correlated significantly(P<0.01),while SVmax-HR,(SVmax-HR/HRR)%and VO₂max,VO₂max/kg did not correlate significantly(P>0.05).3.The correlation analysis of controlling gender,exercise and weight bias showed that SVmax,SVImax and VO₂max are significantly positively correlated(P<0.01);K and b were significantly negatively correlated with VO₂max(P<0.05).The correlation analysis of control sex,exercise and height deviation showed that SVmax,SVImax and VO₂max/kg were significantly positively correlated(P<0.01);K,b and VO₂max/kg were significantly negatively correlated(P<0.05).4.According to the relevant analysis results,the gender,exercise,weight a nd dynamic cardiopulmonary function indicators K,b and SVmax were used as candidate indicators to enter the multiple linear regression analysis of VO₂max.The step-by-step regression analysis method was used to obtain the regression model equation:VO₂max=2.550+0.034×Weight-0.452×K-0.012×b+0.197×Gender(Male=1,Female=0)(R~2=0.892,P<0.01).According to the relevant analysis res ults,the gender,exercise,height and dynamic cardiopulmonary function indicat ors K,b and SVmax were used as candidate indicators for multiple linear regr ession analysis of VO₂max/kg.The stepwise regression analysis method was us ed to obtain the regression model equation:VO₂max/kg=70.848-7.011×K-0.202×b+2.432×Gender(Male=1,Female=0)(R~2=0.736,P<0.01).5.Substitute the verification group data into the selected equation.The results showed that the measured value of the regression equation of VO₂max(2.14±0.49L/min)and the prediction value(2.13±0.43L/min)of the pairing T test results showed that there was no significant difference between the two(P=0.644>0.05);The paired T test results of the predicted regression equation of VO₂max/kg(34.54±6.78ml/kg/min)and the predicted value(32.39±5.37ml/kg/min)showed a significant difference between the two(P=0.028<0.05).Conclusions1.There were gender exercise differences in K,b,SVmax,SVImax,SVmax,SVImax,SVmax-HR and(SVmax-HR/HRR)%.2.SVmax-HR and(SVmax-HR/HRR)%could not be used as valid indicators to predict maximum oxygen uptake.3.Dynamic cardiopulmonary function indicators K value and b value were closely related to exercise,with measurability and better objectivity.It could replace physical activity questionnaire exercise indicators when predicting aerobic exercise ability.4.After correcting other factors,the dynamic cardiopulmonary function indicators K and b were significantly negatively correlated with VO₂max and VO₂max/kg,which was an important candidate index for predicting and evaluating aerobic exercise ability.5.The regression equation of VO₂max for college students based on K and b values of dynamic cardiorespiratory fitness indexes VO₂max=2.550+0.034×body weight-0.452×K-0.012×b+0.197×gender(male=1,female=0)(R~2=0.892,p<0.01),and the goodness-of-fit test was good,and the measured values were consistent with the predicted values,which can be used to predicting VO₂max of college students.