Research On Influence Factors Of Young People Physical Fitness Based On Random Forest Regression

Good health could guarantee individual sustainable development, as body is the capital of revolution and the center of life. However, physical fitness is the precondition and basis of health and intimately correlated to living quality and work efficiency. Young people should pay attention to improving physical fitness, while they are the new power and mainstay of the national comprehensive development. With living standards rising, influenced by environmental factors, civil physical fitness showed that obesity rate increased, qualities like stamina, flexibility and explosive power decreased and various modern civilization disease widely occurred. The majority young people should be aware of the problem, but also need to improve physical effectively by means of enhancing exercise and developing good habits when at work, leisure time, and travel, etc. It is widely acknowledged that physical exercise is great important to health, in fact, transportation, work status and leisure activity those are the every-day contents of people’s life long-term impact on fitness. This paper study the influential degree of each factor indicator on the youth comprehensive physical fitness, and it can achieve nice estimation effect while using Random Forest Regression method because it does not need to pre-set function and meet the classical assumptions of liner regression.This paper reviews and summarizes the existing achievements, having a clear understanding of predecessors’ theories, methods, and contents, to guide its research. After that, combining study objectives and sample data, comprehensive evaluation indicator system and impact factor system. Basted that, this paper learns current physical fitness of young people in Jiangxi Province using Analytical Hierarchy Process(AHP) to determine reasonable weight to calculate aggregative indicator. Let integrated physical indicator being explained variable, and factors explanatory variable, Random Forest Regression model is established and Variable Importance Measure(VIM) is achieved to evaluate the impact of factors——mode of transportation, work status, and leisure activities, on the youth’s fitness.When model building and evaluation, at the first of all, since there is a great imbalance in sample data, which is adjusted by over-sampling. Then, model’s two parameters are introduced and tested the optimization. After that, considering the age of sample has a big span, and the impacts of factors are different on age groups of young people, models of the youth aged 20~24, 25~29, 30~34, and 35~39, are estimated respectively. Using normalized mean squared error(NMSE) to evaluate models’ effects, and comparing the NMSE of Random Forest Regression, Liner Regression, Artificial Neural Network, and Support Vector Machine, it testifies that error of Random Forest Regression method is the lowest. The impacts of factors on the groups have common traits, and show uniqueness as well, providing young people colonies scientific theoretical reference and suggestion to improve physical fitness.