Research And Application Of The Measurement Method For Shanghai Adolescents Physical Activity

Research on adolescent physical activity is still at the initial stage. Studying on measurement of physical activity for national adolescent and evaluation of relationship between physical activity level and health, has a great significance for making standard physical activity recommendation and conducting exercise intervention to improve adolescent's health. Therefore, by researching on application of physical activity measurement, the author expects to provide theoretical and practical evidence for guiding adolescent's fitness.Research methodPartⅠ:Assessment Reliability and Validity of the physical activity questionnaire (CLASS-C) for adolescences.1.Reliability:every subject completed the questionnaire twice, the second time was 7 days after the first. The survey was about physical activity of "past one week". Then compared the consistency of the results.2.Validity:Used multi-sensor SWA as a standard of physical activity measurement, we required subjects to wear SWA for a week consecutively. After 7days, subjects completed the questionnaire again, and then compared the consistency of two methods of measurement.PartⅡ:Research about the correlation between physical activity and fitness of teenagers in Shanghai1. Surveyed 1589 teenagers aged 11 to 17.2. The parameters included height, weight, body fat percentage, vital capacity, stair experiment/400-meter race (junior high school)/1000-meter run (senior high school boys)/800 meters (senior high school girls).3. Analyzed the correlation between physical activity pattern and parameters.PartⅢ:Experiment research on oxygen uptake projection methods of physical activity for teenager.1. The subjects were divided into two groups, formula group and verification group, after completing the measurement of height, weight, chest circumference, body fat percentage, resting heart rate, lung capacity.2. Formula group and verification group took incremental-load exercises on running stage and outdoor, while monitoring their heart rate and gas metabolism. Established prediction equations of oxygen uptake with the results of formula group, and tested the equation by the results of verification group.3. Compared the New Formula with the oxygen uptake prediction formula which recommended by ACSM.Results:PartⅠ:1. Reliability evaluation:correlation coefficients of energy consumption in different intensity are 0.81-0.88 (P<0.01), ICC value is 0.82-0.89, VPA has the highest correlation coefficient with energy consumption; the correlation coefficient of static time is 0.82-0.85 (P<0.01), ICC value is 0.82-0.84.2. Validity:the correlation coefficient of CLASS-C and SWA is 0.31-0.48, (P<0.05), VPA has the highest correlation in energy consumption; Bland-Altman figure shows that the two methods have high consistency in the extent of energy consumption at 40.96-134.92 kcal/d,5.3-126.63 kcal/d,23.47-125.42 kcal/d on MPA, VPA, M-VPA; CLASS-C will underestimate energy consumption, but VPA has the smallest extent.PartⅡ:1. The average of MPA energy consumption (M):819.67-1236.32 kcal/w, (F): 921.46-1306.98 kcal; the average of VPA energy consumption (M) 814.14-1847.08 kcal/w, (F):445.1-1349.05 kcal/w. VPA energy consumption shows significant decline in age of 16 to 17, and boy is more active than girl in PA.2. Detection rate of overweight and obesity of leisure static time less than 2h in different gender are 34.60-35.60%, and more than 2h are 64.4-64.9%.3. The correlation of MPA energy in different BMI has significant differences (P <0.05, P<0.01), VPA energy consumption has significant differences in the vital capacity and endurance of the different levels (P<0.05).PartⅢ:1. Oxygen uptake and loaded heart rate of Formula group shows the highest relationship (P<0.01), followed by lean body mass and body weight. There has no directly relationship in age, vital capacity, and resting heart rate.2. Use multi-linear model analysis method to establish oxygen intake prediction equation. the regression equation is established after testing the significance of independent variables and the constant coefficient:Male:oxygen uptake (ml/min)= 17.24×load heart rate (bmp)+8.76 x lean body mass (kg)-1288.22; Female:oxygen uptake (ml/min)= 18.72×load heart rate (bmp)+5.61 x lean body mass (kg)-1588.793. After retest, the mean relative error is 7.09%-8.19% in boys,7.89-8.72%in girls. New formula SEE=16.29-25.57 ml/min, E=71.03-117.17 ml/min, recommended formula of ACSM SEE=43.58-51.58 ml/min, E=178.63-201.14ml/min.Conclusion1. The adjusted CLASS-C model is consistent with awareness of young people, and it is easy to be understood and reviewed. The content of the investigation, which is accordance with reality of Chinese mainland students, can provide total energy consumption in week and some energy expenditure parameters of moderate and vigorous physical activity. The questionnaire with good reliability and validity can be used to survey adolescent physical and static activities in large scale. However, the survey can hardly cover all physical activities, and the standard value of activity intensity for adolescent is not completed, and memory of different intensity of physical activity can be inaccuracy. All these will influence the reliability and validity of questionnaire.2. Revised CLASS-C can comprehensively reflect the model of physical and static activity of adolescent in Shanghai. Physical activity of adolescent in Shanghai has reached the international recommended level in general. However, senior students are lacking of physical activity, and there has a gender difference in physical activity model. Having lessons and extra curricular after class, doing homework are the most static activities. People who has long time of leisure static activities has high rate of overweight and obesity. There is a Dose-response relationship between different intensity of physical activity and fitness.3. The oxygen uptake estimated equation which is established by the independent variable of load heart rate and body weight, can accurately predict the change of oxygen uptake in physical activity. The equation, which considers the physiological mechanism of oxygen uptake, the characteristics and individual differences of adolescent, is more precise than the formula recommended by ACSM. Establishing the oxygen uptake prediction equation by the analysis method of multilevel linear model can provide a theoretical basis on usage of different types of sport. However, the equation has limitation on predicting maximal oxygen uptake in rest and low intensity.