Table 1

Descriptive characteristics of the analytical sample for all child-level variables (n=425)

VariableMean (SD) or n (%)
TotalBoysGirls
Demographic/biological
 Age (years)10.9 (0.4)10.9 (0.4)10.9 (0.5)
 Sex (% male)183 (43.1)
 BMI z-score*0.4 (1.1)0.4 (1.0)0.4 (1.1)
Psychological
 Self-efficacy score (0–4)†2.5 (0.8)2.5 (0.8)2.5 (0.8)
Behavioural
 TV viewing (hours/day)1.8 (1.0)1.8 (1.1)1.7 (1.0)
 Computer use (hours/day)1.2 (1.1)1.6 (1.2)0.9 (0.8)
 Sport participation (% yes)292 (68.7)144 (78.7)148 (61.2)
 Transport mode to school (% active)276 (64.9)121 (66.1)155 (64.1)
Home environment
 SES (highest parental education level)
  University degree199 (46.8)93 (50.8)106 (43.8)
  A levels or equivalent105 (24.7)47 (25.7)58 (24.0)
  GCSEs or less121 (28.5)43 (23.5)78 (32.2)
 Parent support score (0–4)†1.6 (0.8)1.6 (0.7)1.6 (0.8)
 Ownership of a mobile phone (% yes)243 (57.2)86 (47.0)157 (64.9)
 Outdoor time after school (hours/day)1.7 (1.3)1.7 (1.3)1.7 (1.4)
Outcome variables
 LPA (min/day)286.3 (45.2)285.5 (43.3)286.9 (46.7)
 MPA (min/day)43.3 (13.0)48.0 (13.9)39.8 (11.0)
 VPA (min/day)20.9 (11.5)26.1 (12.6)17.0 (8.7)
 Meeting the MVPA guidelines (% yes)‡224 (52.7)131 (71.6)93 (38.4)
 Mean accelerometer waking wear time (min/day)845.7 (49.7)853.5 (50.3)839.7 (48.4)
  • *BMI z-score was derived from WHO growth reference data.28

  • †Higher scores denote greater levels of self-efficacy and parent support.

  • ‡% of children with a mean of at least 60 min of MVPA per day.11

  • BMI, body mass index; GCSE, General Certificate of Secondary Education; LPA, light-intensity physical activity; MPA, moderate-intensity physical activity; MVPA, moderate-to-vigorous physical activity; SES, socioeconomic status; TV, television; VPA, vigorous-intensity physical activity.