This study analyzes the relationships between leisure time physical activity (LTPA), sedentary behaviors, socioeconomic status, and perceived environmental variables. The sample comprised 815 girls and 746 boys. In girls, non-LTPA participants reported significantly more screen time. Girls with safety concerns were more likely to be in the non-LTPA group (OR = 0.60) and those who agreed with the importance of aesthetics were more likely to be in the active-LTPA group (OR = 1.59). In girls, an increase of 1 hr of TV watching was a significant predictor of non-LTPA (OR = 0.38). LTPA for girls, but not for boys, seems to be influenced by certain modifiable factors of the built environment, as well as by time watching TV.
Jorge Mota, Helena Gomes, Mariana Almeida, José Carlos Ribeiro, and Maria Paula Santos
Luisa Aires, Pedro Silva, Gustavo Silva, Maria Paula Santos, José Carlos Ribeiro, and Jorge Mota
The purpose of this study was to analyze the relation between body mass index (BMI), Cardiorespiratory Fitness (CRF), and levels of physical activity (PA) from sedentary to very vigorous intensities, measured by accelerometry, in students from a middle and high school.
This cross-sectional study included 111 children and adolescents, age 11 to 18 years. PA was assessed with an accelerometer for 7 consecutive days (1 minute epoch) using specific cut-points. PA components were derived using special written software (MAHUffe). CRF was assessed by maximal multistage 20m shuttle run. T-test was used to test differences between BMI groups, Pearson’s correlation, to analyze correlations between all variables and multinomial logistic regression, and to predict the value of BMI categories.
This paper provides evidence that BMI was inversely and significantly correlated with CRF. Only CRF was correlated with Vigorous and Very Vigorous PA levels and total amount of PA. Children with Overweight/Obesity were less likely to perform more laps than normal weight counterparts. The total amount or intensity level of PA did not show any influence on BMI level.
Low CRF is strongly associated with obesity, which highlights the importance of increasing CRF for a protective effect even in youth. No associations were found for PA and BMI.
Jorge Mota, José Carlos Ribeiro, Joana Carvalho, Maria Paula Santos, and Júlio Martins
The aim of this study was twofold (1), to examine the prospective relationship of baseline TV viewing with BMI and CRF both at baseline and over a 2-year period, and (2) to examine the prospective relationship of baseline TV viewing and changes (Δ) on BMI and CRF over a 2-year period. Data were collected in a sample of 135 (64 girls) rural children ages 7 yr-old from elementary schools in Fundao, Portugal. Obesity status was obtained by the age-sex specific BMI cut points and CRF by a 9 min run test. TV viewing was also analyzed and children were assigned as one of two groups: the low TV watching (LTV), and high TV watching (HTV), users based upon them reported to spend less or more than 2 h/day watching TV, respectively. Logistic regression showed that those who were assigned to HTV group were 2.4 times (OR = 2.48; p = .04) more likely to be classified as unfit at time 1. Further the data showed that the LTV were more likely (OR = 0.36; p = .02) to be classified in high ΔCRF change over time. The findings of this study suggest that there was a significant inverse association between times spent watching TV and CRF but not BMI over a 2-yr period.
Jorge Mota, Nuno Delgado, Mariana Almeida, José Carlos Ribeiro, and Maria Paula Santos
The purpose of this study was 1) to compare physical activity levels according to body-mass index; 2) to determine which, if any, neighborhood perceived attributes were related to overweight.
The sample comprised 610 girls age 14.7 ± 1.6 y. Girls were grouped into normal weight and overweight. Environmental variables and physical activity were assessed by questionnaire.
No significant differences were found in physical activity levels between normal weight and overweight girls. Logistic regression analysis revealed that girls who agreed that “there is so much traffic on the streets that it makes it unpleasant to walk in the neighborhood” were more likely to be overweight (OR = 1.78; 95% CI 1.10 to 2.89).
The study found no relationship between perceptions of the environment and overweight among Portuguese girls, except for perceptions of security for walking in the neighborhood.