A Study On Cardiorespiratory Function Of Non-physical Education Students-regression Equation For Predicting Maximal Oxygen Uptake

Objective:The decline of cardiopulmonary function in college students has been widely concerned.Cardiopulmonary function plays an important role in the evaluation of physical health.The maximum oxygen uptake has been widely used as an objective index to evaluate cardiopulmonary endurance.In the study of maximal oxygen uptake,the direct measurement method is not convenient for large sample population due to the limited experimental equipment and site,as well as high cost.Indirect measurement method is more convenient and suitable for large sample population,but there are some errors in accuracy,while mathematical model rule has small errors in predicting the maximum oxygen uptake.Previous predictions of VO₂Max were mainly based on the improvement of test methods and the speculation of a single refined index.However,this study measured VO₂Max through the increasing load running table test,recorded relevant indicators during the test process,analyzed various factors affecting VO₂Max,and established the relevant mathematical model of VO2 Max by selecting indicators with high correlation with VO₂Max.Different combinations of indicators are carried out to establish a more accurate prediction model of the maximum oxygen uptake of college students,enrich the way of measuring the maximum oxygen uptake of Chinese college students,improve the accuracy of prediction,at the same time,explore the influence of various body indicators on the maximum oxygen uptake of college students,make more accurate research on the physique of college students,but also provide reference for scientific physical exercise of Chinese college students.Methods:In this study,160 college students without professional sports and strength training background from Shandong Institute of Physical Education were selected and divided into the model group（60 males and 60 females）and the validation group（20 males and 20 females）.The experiment was divided into two parts.In the first part,height,weight,body fat percentage and other indicators were measured for subjects in the model group and verification group.The maximum oxygen uptake was measured for subjects on the running platform according to Bruce’s scheme,and the relevant indicators were analyzed descriptively.Gender,height,weight,CO,RR,v VO2max and running distance were selected as independent variables to construct the regression equation of maximal oxygen uptake prediction.The second part uses the data of the verification group to check the prediction effect of the prediction model.Results:1.All indexes of the model group and the verification group were in line with normal distribution.2.There were no significant differences between boys and girls in age,body fat percentage,resting heart rate,maximum heart rate and reserve heart rate（P>0.05）,but there were significant differences among height,body weight,BMI,waist-to-hip ratio,maximal oxygen uptake,relative oxygen uptake,SV,CO,RR,v VO₂max and running distance（P<0.05）.Except RR,other indicators showed that boys were higher than girls.3.VO₂max-HR is correlated with HRmax and HRR;There was significant correlation between HRmax and HRR.VO₂max-HR,HRmax and HRR had low correlation with VO2 Max.In the process of increasing load,except for the sixth and seventh stages,the heart rate of each stage is correlated with the maximum oxygen uptake.4.Through correlation test,gender,height,weight,BMI,RR,v VO₂max,CO and running distance were significantly correlated with VO2 Max;gender,height,weight,v VO₂max and CO were highly correlated with VO₂Max,while other indicators were moderately correlated.5.Finally,gender,height,weight,RR,CO,v VO₂max and running distance were selected as independent variables to construct the linear regression equation of maximal oxygen uptake.6.Equation 1:Maximal oxygen intake=-0.885-0.074×gender+1.233×height+0.010×weight+0.069×v VO₂max-0.003×RR（R=0.934,adjusted R2=0.872,gender is the categorical variable,male=1,female=2）;Equation 2:Maximal oxygen uptake=-0.7744-0.154×gender+1.482×height+0.009×weight+0.001×running distance-0.005×RR（R=0.915,adjusted R2=0.841,male=1,female=2）.7.The two equations have research significance,and the predicted values of the equations are highly correlated with the measured values,and there is no significant difference between them,so the prediction of the equations is better.Conclusion:1.VO₂max has nothing to do with resting heart rate and Max heart rate,but is related to heart rate during exercise,and other heart rate indicators need further study.2.The maximal oxygen uptake speed can reflect the critical state when the body reaches the maximal oxygen uptake,and can also be tested by simple methods to provide certain reference value for physical exercise of college students.3.The two equations have good predictability,providing a new method for non-sports major college students to predict the maximum oxygen uptake,and also enriching the indirect measurement methods of the maximum oxygen uptake.4.There are many factors affecting the maximum oxygen uptake,and different indicators can be selected according to different test groups.