Japanese Adolescents Are the Most Physically Fit and Active in East and Southeast Asia

*1)Faculty of Health and Sports Science, Juntendo University, Chiba, Japan, *2)Graduate School of Health and Sports Science, Juntendo University, Chiba, Japan, *3)Physical Education & Sports Science, Nanyang Technological University, Singapore, *4)Department of Taekwondo, Kyung Hee University, Seoul, Korea, *5)Institute of Community Health Care, National Yang-Ming University, Taipei, Taiwan, *6)Faculty of Sport Sciences, Shanghai University of Sport, Shanghai, China, *7) Faculty of Health Sciences, The National University of Malaysia, Kuala Lumpur, Malaysia, *8) Institute of Nutrition, Mahidol University, Nakhon Pathom, Thailand, *9)Faculty of Education, The Chinese University of Hong Kong, Hong Kong SAR, China


Introduction
There are strong evidences showed that lack of physical activity and low levels of physical fitness were important predictors for some chronic diseases including obesity and cardiovascular disease 1) .Some longitudinal studies also indicated that the physical fitness and physical activity levels during adolescence were associated with their disease risk in adulthood 2) 3) .Some studies suggested that culture, education system, economic and social context may influence childrenʼs physical activity, physical fitness, and weight status 4) .Comparing the physical activity, physical fitness, and weight status is very important in physical activity promotion and obesity prevention in the future.In 2012, The Asia-Fit Study was launched in order to compare levels of physical fitness, physical activity and obesity of adolescents among major metropolitan cities in East and Southeast Asia 5) .The study report was summarized in a final report submitted to National University of Singapore-Global Asia Institute by Prof. Stanley Sai-Chuen Hui (The Chinese University of Hong Kong) and our study group.We also reported some conferences 6)-9) .
Focusing on Japanese data in the final report, we compared the level of physical activity, physical fitness, and obesity of adolescents among major metropolitan cities in East and Southeast Asia.Unpaired t-tests were used to test statistical differences between the means of Japanese adolescents and the other countriesʼ adolescents.Cohenʼs d effect size was used to indicate the standardized difference between two means.For all analyses, significance was set at an alpha level of p < 0.05.

Results and discussions
Prevalence of sports club participants with two hours or more of physical activity each week in Tokyo (Male: 49.7%, female: 36.7%) was considerably higher than the other cities (Male: 15.7%, female: 10.5%).T-tests, by gender, indicated that all measures of Japanese adolescents were significantly greater than the other adolescents (Table -2  According to a national survey in Japan 12) , the rate of participation of sports club conducted outside school is quite low compared with sports club after class in school.Engaging in sports club activity obviously increases physical activity for both males and females.Therefore, our data demonstrated that high participation rate of sport club activity at school played a role in maintaining a high MVPA level among Japanese adolescents.These findings might suggest that promotion of sports club activity in school is one the most important factors to decrease physically unfit, especially in endurance fitness, and inactive adolescents in Asia.

Conclusions
These findings suggested that Japanese adolescents were the most physically fit and active, especially endurance and MVPA level were much greater than the other countriesʼ adolescents.

Table - 1
Sample size and age for each city

Table - 2
Comparisons of Japanese adolescents and the other countriesʼ adolescents