Study On The Relationship Between Cardiorespiratory Endurance And Executive Function And Exercise Intervention Of Tibetan Children And Adolescents In High Altitude Areas

The Qinghai-Tibet plateau,known as the"roof of the world",is a typical high-altitude region.Especially in the context of low temperatures and hypoxia,Tibetans have undergone significant physiological and genetic changes,resulting in the unique characteristics of Tibetan physical health and brain development.Studies have confirmed that exposure to high altitudes harms the physical and cognitive health of children and adolescents.As the core element of physical health,cardiorespiratory endurance is an important indicator reflecting the physical health of children and adolescents,as well as an independent risk predictor of various diseases.Exploring the growth characteristics and influencing factors of Tibetan children and adolescents’cardiorespiratory endurance can provide references for the healthy development of their cardiorespiratory endurance and further promote their physical fitness,thereby promoting their healthy development.However,previous studies on Tibetan cardiorespiratory endurance in high-altitude areas mainly focused on adults.The investigation of its influencing factors involved inadequate factors and limited sample size,and the intervention studies were mainly focused on short-term aerobic aerobics in a small sample of adults in the laboratory.As an advanced function of cognition,executive function is a key link in the intellectual development of children and adolescents and has an important impact on their current and adult academic achievements,wealth and income,family happiness,and interpersonal relationships.Exploring the executive function characteristics and influencing factors of Tibetan children and adolescents can provide a theoretical basis for their healthy development and further promote the development of executive function and intelligence.However,previous studies mainly focused on plain areas,and there is no investigation and research on a large sample of Tibetan children and adolescents in high-altitude areas.Physical exercise can not only strengthen the body but also promote the development of the brain.Relevant literature has reported the relationship between cardiorespiratory endurance and executive function of children and adolescents in the plains,but the conclusions are not consistent,and there is a lack of control of additional interfering variables or confounding factors.To our best knowledge,no research has been found on the relationship between cardiorespiratory endurance and executive function of Tibetan children and adolescents in high-altitude areas.Given the above,this study used the stratified cluster sampling method to select8446 Chinese Tibetan children and adolescents aged 7～18 from the four regions of Tibet in China:Lhasa,Naqu,Lingzhi,and Changdu（which is 3,650 meters,4,500meters,3,500 meters,and 3,100 meters above the horizon,respectively）.Cardiorespiratory endurance and executive function tests were carried out from August 2019 to December 2020.At the same time,information on demographics,body composition,physical activity,family environment,sleep,and eating habits was also collected,aiming to explore the characteristics and influencing factors of cardiorespiratory endurance and executive function for Tibetan children and adolescents in high altitude areas.Meanwhile,exercise intervention was carried out to explore the investigate the effects of exercise on cardiopulmonary endurance and executive function,providing theoretical references for the development of cardiopulmonary endurance and executive function of Chinese Tibetan children and adolescents in high altitude areas.The four studies involved are shown as follows:StudyⅠCardiopulmonary endurance level and its influential factors of Chinese Tibetan children and adolescentsObjective:To compare the cardiorespiratory endurance levels of Chinese Tibetan children and adolescents at high altitudes and Han children and adolescents,explore the influencing factors of the cardiorespiratory endurance of Chinese Tibetan children and adolescents.Method:（1）A stratified cluster sampling method was used to sample 8446 Tibetan children and adolescents aged 7～18 years from the four regions of Tibet:Lhasa,Naqu,Lingzhi,and Changdu.The 20-meter shuttle run test and questionnaire survey were carried out.T-test,one-way analysis of variance,pearson correlation,and multiple linear stepwise regression analysis were used to conduct data analysis.（2）A total of 5,346 Han children aged 7～18 years were selected from seven geographical regions in China.After conducting 20-meter shuttle run test,t-test method was used to compare the cardiorespiratory endurance between Tibetan and Han ethnic groups.Result:（1）The VO_2maxscores of the Han boys aged7-16 years old were 0.91-4.51 m L/kg.min higher than those of the Chinese Tibetan boys aged 17-18 years.Nevertheless,the VO_2maxscores of the Chinese Tibetan boys aged 17-18 years old were 1.10 and 1.65m L/kg.min higher than those of the Han boys.The same pattern exists among girls.（2）The mean and standard deviation of20m SRT laps,stages/minutes,the speed at the last stage,and the VO_2maxwas（34.37±20.28）laps,（10.28±1.10）km/h,（42.51±4.84）ml/kg.min for Chinese Tibetan boys and（24.45±11.45）laps,（9.77±0.67）km/h,（39.63±4.95）m L/kg.min for Chinese Tibetan girls,respectively.In general,all the indicators were higher for boys than girls.（3）The higher the body composition（body mass index,chest circumference,waist circumference,hip circumference）of Chinese Tibetan children and adolescents,the lower the VO_2max,showing a negative correlation（r=-0.343,-0.402,-0.309,-0.431,respectively,P<0.01）.（4）High intensity physical activity time was positively correlated with VO_2max（r=0.062,P<0.01）in Chinese Tibetan children and adolescents.（5）In terms of family factors,the VO_2maxof Chinese Tibetan children and adolescents from one-child families was 1.05m L/kg.min higher than those from non-one-child families（P<0.01）.The VO_2maxof Chinese Tibetan children and adolescents whose fathers had a college education or above was 2.05m L/kg.min higher than that of the children and adolescents whose fathers had primary school education or below,and the differences were statistically significant（P<0.01）.The VO_2maxof Chinese Tibetan children and adolescents whose mothers had a college education or above was 2.49 m L/kg.min higher than that of the children and adolescents whose fathers had primary school education or below,and the differences were statistically significant（P<0.01）.（6）Sleep time on school days and weekends are positively correlated with VO_2max（r=0.262,0.163,P<0.01）in Chinese Tibetan children and adolescents.（7）Chinese Tibetan children and adolescents who ate breakfast and almost no sugary drinks had the highest VO_2max,which was 41.72,42.63m L/kg.min,respectively,and the difference between categories are statistically significant（F=20.381,65.945,P<0.001）.Summary:（1）The cardiopulmonary endurance of Chinese Tibetan children and adolescents was lower than that of the Han ethnic group during 7-16 years old,but it is significantly higher than that of the Han ethnic group at 17 and 18 years old.（2）In general,the performance of cardiorespiratory endurance was higher for boys than girls,and the differences increased with percentiles.（3）Factors such as family environment,dietary behavior,body composition,physical activity,and sleep time have an impact on the cardiopulmonary endurance of Chinese Tibetan children and adolescents.StudyⅡThe performances and influencing factors of executive function for Chinese Tibetan children and adolescentsObjective:To explore the performances and influencing factors of executive function for Chinese Tibetan children and adolescents.Method:Based on StudyⅠ,2389 Chinese Tibetan children and adolescents aged 10～18 in Lhasa and Naqu were selected as participants.Executive function（inhibition,refresh,and conversion）tests and questionnaires were conducted.T-test,one-way analysis of variance,pearson correlation,and multiple linear stepwise regression analysis were used to conduct data analysis.Result:（1）The response times of inhibition,refresh（1-back,2-back）and conversion function were 19.88,997.92,1086.36,399.06 ms for Chinese Tibetan boys,and 19.41,995.50,1090.70,397.50 ms for Chinese Tibetan girls,respectively.There was no statistical significance between boys and girls（P>0.05）.The accuracy of each sub-function of executive function ranged from 0.87 to 0.92,and there was no statistical significance between boys and girls（P>0.05）.（2）The higher the learning stages,the shorter the response time of inhibition,refresh（1-back,2-back）and conversion function,and the difference between different learning stages were significantly（F/t=32.293,26.324,6.706,31.318,respectively,P<0.001）.（3）In general,the higher the waist circumference,the longer the response time of refreshing（1-back,2-back）and conversion function（r=0.146,0.203,0.123,respectively,P<0.01）.（4）The longer the daily high-intensity physical activity time,the shorter the response time of refreshing（2-back）and conversion function（r=-0.143,-0.068,respectively,P<0.01）.（5）In terms of family factors,the performances of the 1-back function of children and adolescents whose parents had a college education or above were better than that of those with primary school education or below（β=-0.137,P<0.001）;Children and adolescents whose parents supported their children participating in physical exercise performed better in inhibition and refresh（1-back,2-back）function than those whose parents did not support their children（β=-0.177,-0.271,-0.118,P<0.01）.（6）The sleep time on school days and weekends was positively correlated with executive function and all three sub-functions（P<0.01）.（7）Compared with children and adolescents who regularly drank sugar beverages,those who almost did not drink sugary beverages had a shorter response time of the refresh function（2-back）（β=-0.058,P<0.05）.Summary:（1）There was no difference between genders in the response time and accuracy of executive function among Chinese Tibetan children and adolescents.（2）The higher the learning stage/age,the better the executive function performance.（3）Chinese Tibetan children and adolescents with lower body composition（waist circumference）have better performance of refresh and conversion function.（4）In general,the longer the high-intensity physical activity time,the better the performance of refresh and conversion function.（5）Children and adolescents with a better family environment（parents with higher education level and support for their children to participate in physical exercise）have better executive function performance.（6）Chinese Tibetan children and adolescents who controlled their sugar drinks performed better in refresh function.Study Ⅲ The relationship between the cardiorespiratory endurance and executive function of Chinese Tibetan children and adolescentsObjective:To explore the relationship between cardiorespiratory endurance and executive function of Chinese Tibetan children and adolescents.Methods:Based on StudyⅠand StudyⅡ,pearson correlation analysis and multiple linear hierarchical regression analysis were used to explore the correlation between the cardiorespiratory endurance and executive function of Chinese Tibetan children and adolescents.Result:In general,there is a correlation between the VO_2maxand the response time of inhibition function,refresh function（1-back,2-back）,and the conversion function（r=0.118,-0.133,-0.274,-0.215,respectively,P<0.01）.（2）Remaining the other influencing factors of the reaction time of refresh function（1-back,2-back）,and conversion function unchanged,after adding VO_2maxas a variable,multiple linear stratified regression analysis showed thatΔR²equaled to 0.030,0.051,and 0.075（P<0.01）.VO_2maxplayed a negative predictive role in the reaction time of the refresh function（1-back,2-back）,and the conversion function of Chinese Tibetan children and adolescents in high altitude areas of China（β=-0.031,-0.307,-0.320,P<0.001）;With VO_2maxincreased by 1 m L/kg.min,the reaction time of the 1-back test,the 2-back test,and conversion function shortened by 13.809ms,19.421ms,and 13.912ms,respectively.Summary:In general,with other influencing factors unchanged,there is a positive correlation between cardiorespiratory endurance and refresh function,and conversion function.Study Ⅳ Experimental study on the effect of an exercise intervention on the executive function of Chinese Tibetan junior school studentsObjective:To explore the effects of an exercise intervention on cardiopulmonary endurance and executive function of Chinese Tibetan junior school students.Method:A total of 184 students from the first grade of a middle school in Lhasa were selected as participants,and were divided into control group（N=81）and intervention group（N=103）.The intervention group received 36 times exercise interventions,while the control group implemented the school’s normal daily teaching plan.Before and after the intervention,demographic information,cardiopulmonary endurance,and executive function were investigated and compared for both the intervention group and control group.Result:After the intervention,（1）In terms of cardiorespiratory endurance,the 20-m SRT,the speed at the last stage,VO_2maxincreased by 4.50 laps,0.65km/h,3.89m L/kg.min for Chinese Tibetan boys（P<0.001）,and 9.09 laps,0.53km/h,2.72m L/kg.min for Chinese Tibetan girls（P<0.001）.（2）In terms of executive function,1)the reaction time of inhibitory function decreased by 11.83 ms for boys and 7.62 ms for girls（both P<0.05）.2)The reaction time of the 1-back test and the 2-back was reduced by 125.55ms and 194.34ms for boys,175.00ms,and218.20ms for girls（both P<0.05）.3)The reaction time of conversion function decreased by 116.10 ms for boys（P<0.05）and by 22.79 ms for girls（P>0.05）.There were no significant differences in all the cardiopulmonary endurance and executive function indexes for the control group before and after the intervention（P>0.05）.Summary:After the intervention,the cardiopulmonary endurance of Chinese Tibetan junior school students was significantly higher than that before the experiment.The performance of inhibition,refresh,and conversion function of boys and inhibition and refresh function of girls were improved.Conclusions:（1）In general,the cardiorespiratory endurance of Chinese Tibetan children and adolescents during 7-16 years old is lower than that of the Han ethnic group and significantly higher than that of the Han ethnic group at 17 and 18 years old.Chinese Tibetan children and adolescents with lower body composition,longer periods of high-intensity physical activity,better family environment,adequate sleep,reasonable diet,and control of sugary beverages have higher levels of cardiorespiratory endurance.（2）Chinese Tibetan children and adolescents with higher learning stage,lower waist circumference,longer time of high-intensity physical activity,parents having higher education level,and supporting physical exercise have better executive function performance.（3）With other influencing factors remaining unchanged,the higher the cardiopulmonary endurance of Chinese Tibetan children and adolescents,the better the performance of executive function refresh and conversion function.（4）After the exercise intervention,the cardiopulmonary endurance level of Chinese Tibetan junior school students was improved,and the inhibition,refresh,and conversion function of boys and the inhibition and refresh function of girls were also improved.