Purpose: To investigate the association between patterns of sedentary behavior and obesity indicators among adolescents. Methods: This was a cross-sectional study conducted among 389 adolescents (186 boys) aged 10–14 years. Body mass index, body fat (skinfolds), and waist circumference were adopted as outcomes. Sedentary behavior patterns (total time, bouts, and breaks) measured through accelerometry (GT3X and GT3X+; ActiGraph, Pensacola, FL) were adopted as exposures. Peak height velocity, moderate to vigorous physical activity (accelerometer), cardiorespiratory fitness (Léger test), sex, and chronological age were adopted as covariates. Linear regression models adjusted for covariates were used to determine associations between outcome and exposure variables. Results: The mean age of adolescents was 11.8 (0.7) years. Boys were more active than girls (P < .001). Accumulating shorter bouts (1–4 min) of sedentary behavior was negatively associated with body mass index (β = −0.050; 95% confidence interval [CI], −0.098 to −0.003) and waist circumference (β = −0.133; 95% CI, −0.237 to −0.028). Similarly, a higher number of breaks in sedentary behavior were negatively associated with body mass index (β = −0.160; 95% CI, −0.319 to −0.001) and waist circumference (β = −0.412; 95% CI, −0.761 to −0.064). Conclusion: Shorter bouts of sedentary behavior (1–4 min) and a higher number of breaks of sedentary behavior were associated with lower adiposity. Our findings also suggest that breaking up sedentary time to ensure bouts of sedentary behavior are short might contribute to the prevention of obesity in adolescents.
André O. Werneck, Evelyn C.A. Silva, Maria R.O. Bueno, Lidyane Z. Vignadelli, Adewale L. Oyeyemi, Catiana L.P. Romanzini, Enio R.V. Ronque and Marcelo Romanzini
Alessandra Madia Mantovani, Manoel Carlos Spiguel de Lima, Luis Alberto Gobbo, Enio Ricardo Vaz Ronque, Marcelo Romanzini, Bruna Camilo Turi-Lynch, Jamile Sanches Codogno and Rômulo Araújo Fernandes
Purpose: To analyze the relationship between engagement in sports in early life and bone variables among adults of both sexes. Methods: The sample was composed of 225 men and women. Demographic data were collected, and dual-energy X-ray absorptiometry was used to assess bone mineral density, bone mineral content, and lean soft tissue. Sports participation in early life was assessed by an interview including childhood and adolescence. Consumption of tobacco and alcohol was also assessed by interview and the habitual physical activity level by a pedometer. Results: Inactive men had bone mineral content around 11% lower than active men in childhood or adolescence, whereas for women, this difference represented around 14%. Active men had 74% less fat mass than inactive men in early life, and the difference was 67% for women. Early sports participation explained the differences in whole-body bone mineral content (16.8%, P-value = .005) and bone mineral density (8.8%, P-value = .015), as well as bone mineral density in lower limbs (18.9%, P-value = .001) among women. Conclusion: Adults engaged in sports in early life have higher bone mass than their inactive peers, especially women.
André O. Werneck, Adewale L. Oyeyemi, Rômulo A. Fernandes, Marcelo Romanzini, Enio R.V. Ronque, Edilson S. Cyrino, Luís B. Sardinha and Danilo R. Silva
Background: This study aims to describe the regional prevalence and patterns of physical activity (PA) and sedentary behavior among Brazilian adolescents. Methods: Data from the Brazilian Scholar Health Survey, a nationally representative survey of ninth-grade adolescents [mean age: 14.29 y (14.27–14.29)] conducted in 2015 (n = 101,445), were used. Outcomes were television viewing, sitting time (ST), total PA, and active traveling collected via self-administered questionnaire. Information on frequency of physical education classes and type of school was collected from the school’s director. Frequencies with 95% confidence intervals were used to determine the prevalence and patterns of outcomes. Results: Higher prevalence of PA (≥300 min/wk) and ST (>4 h/d) was found in Midwest (PA = 38.0%; ST = 44.5%), South (PA = 37.6%; ST = 50.1%), and Southeast (PA = 36.1%; ST = 49.3%) compared with Northeast (PA = 29.7%; ST = 36.9%) and North (PA = 34.4%; ST = 34.8%) regions of Brazil. ST was higher among adolescents from private schools (51.5%) than public schools (42.9%), whereas active traveling was greater among students of public schools than private schools (62.0% vs 34.4%). Most inequalities in outcomes between capital and interior cities were in the poorest regions. Conclusions: The results indicate that national plans targeting regional inequalities are needed to improve PA and to reduce sedentary behavior among Brazilian adolescents.