The Role of Urban Environment, Social and Health Determinants in the Tracking of Leisure-Time Physical Activity Throughout Adolescence.
PURPOSE
Adolescence may be a period particularly relevant for acquisition of lifelong habits of physical activity (PA). We investigated the tracking of leisure-time PA from 13 to 17 years old and the influence of urban environment and other determinants.


METHODS
As part of the EPITeen cohort (Portugal), we evaluated 969 adolescents living in the city of Porto. Participants were assembled in public and private schools at 13 years and reevaluated at 17 years. Leisure-time PA was evaluated by self-reported questionnaires. The shortest routes from residence to urban green spaces and open sports spaces were calculated using the street network within a Geographical Information System. Odds ratio (OR) and 95% confidence intervals were calculated by multinomial logistic regression.


RESULTS
Among sedentary girls at 13 years, 33.1% were still sedentary at 17 years, 39.8% changed to low, 22.3% to moderate, and only 4.6% changed to vigorous PA. In boys, the respective values were 32.3%, 17.3%, 36.2%, and 14.2%. High PA levels were maintained by 19.5% of the girls and by 41.1% of the boys. After adjustment for parental education and body image at 13 years, practice of sports at 13 years was strongly associated with stable high PA at 17 years: in girls OR = 3.96 (2.21, 7.12); in boys OR = 6.81 (3.30, 14.07). Distance to urban green spaces or to open sports spaces was not associated to changes in leisure-time PA.


CONCLUSION
Practice of sports in early adolescence may be important to promote maintenance of high PA. Urban environment in the vicinity of residence did not affect changes in the practice of leisure-time PA.
['Magalhães|Alexandre Pedro Tavares da Fonseca|APTDF|', 'Pina|Maria de Fátima Rodrigues Pereira de|MFRP|', 'Ramos|Elisabete da Conceição Pereira|EDCP|']
D000293:Adolescent D000294:Adolescent Behavior D015331:Cohort Studies D015444:Exercise D005260:Female D006304:Health Status D006801:Humans D007899:Leisure Activities D008297:Male D011174:Portugal D012919:Social Behavior D011795:Surveys and Questionnaires D014505:Urban Population
Leisure-time physical activity Adolescence Urban green space Open sports space Cohort study