Skip to main content

Table 1 Characterization of sample by sex: middle school cohort, ELANA study, 2010 and (2012)

From: Changes in physical activity and screen time related to psychological well-being in early adolescence: findings from longitudinal study ELANA

Variables Male N = 277 Female N = 249 P value
T1 (2010)
 Age (CI 95 %) 11.2 (11.0–11.3) 11.0 (10.9–11.1) 0.037 a
Sexual maturation (%)
 Pre-pubescent 5.8 6.4 <0.001 b
 Early spurt 73.1 28.9
 Maximum speed peak 16.3 47.0
 Slowing growth 4.4 17.7
Type of school (%)
 Public 30.7 30.9 0.953b
 Private 69.3 69.1
Assets Indicator (%)
 Less asset ownership 25.3 12.7 <0.001 b
 More asset ownership 74.7 87.3
BMI (Kg/m2)
 Mean (CI 95 %) 20.6 (20.1–21.2) 20.2 (19.7–20.7) 0.265a
 Normal (%) 82.4 87.8  
 Overweight/obesity (%) 17.6 12.2 0.090b
MVPA (min/day)
 Mean (CI 95 %) 66.0(58.7–73.3) 43.9(38.4–49.5) <0.001a
  > 60 min/dayc (%) 36.5 22.5  
  ≤ 60 min/day ((%) 63.5 77.5 <0.001 b
Screen time (min/day)
 Mean (CI 95 %) 320.9 (293.6–348.2) 301.1(271.1–331.1) 0.337a
  ≤ 4 h/dayc (%) 48.0 53.6  
  > 4 h/day (%) 52.0 46.4 0.199b
Psychological well-being
 Mean (CI 95 %) 49.5 (47.5–50.1) 50.2(48.8–51.4) 0.405a
 Poor (%) 12.3 13.3  
 Good (%)c 87.7 86.7 0.737b
T2 (2012)
MVPA (min/day)
 Mean (CI 95 %) 42.1(37.2–46.9) 29.5(24.7–34.3) <0.001 a
  > 60 min/dayc (%) 26.0 13.3  
  ≤ 60 min/day ((%) 74.0 86.7 <0.001 b
Screen time (min/day)
 Mean (CI 95 %) 355.5(326.3–384.7)d 381.1(348.9–413.3)d 0.245a
  ≤ 4 h/dayc (%) 43.7 39.8  
  > 4 h/day (%) 56.3 60.2 0.362b
  1. CI 95 % confidence interval 95 %, BMI body mass index, MVPA moderate and vigorous physical activity; aT test for independent sample by gender; bQui Square test by gender; cReference category- Highers scores of psychological well-being; dSignificant difference between means over time (p < 0,05)-Pared T test
\