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Table 1 Participant Characteristics

From: Tracking of TV and video gaming during childhood: Iowa Bone Development Study

  Age 5 Age 8 Age 11 Age 13
  Boys Girls Boys Girls Boys Girls Boys Girls
  (n = 205) (n = 229) (n = 193) (n = 222) (n = 171) (n = 211) (n = 168) (n = 189)
Age (yr) 5.2 ± 0.4 5.3 ± 0.5* 8.7 ± 0.6 8.7 ± 0.6 11.2 ± 0.3 11.2 ± 0.3 13.3 ± 0.4 13.3 ± 0.4
Height (cm) 112 ± 6 111 ± 6 134 ± 7* 132 ± 7 149 ± 8 149 ± 8 163 ± 10* 160 ± 7
Weight (kg) 21 ± 4 20 ± 4 33 ± 10 32 ± 9 45 ± 13 44 ± 12 58 ± 16 56 ± 15
Fat Mass (kg) 3.9 ± 2.1 4.6 ± 2.4* 8.0 ± 6.3 9.2 ± 5.9 12.7 ± 9.2 14.2 ± 8.7* 15.4 ± 11.6 17.9 ± 10.6*
% BFa 18.8 ± 5.3 22.8 ± 6.0* 22.6 ± 9.3 27.7 ± 8.8* 26.4 ± 10.9 30.5 ± 9.9* 23.4 ± 12.6 29.3 ± 9.9*
MVPA (minutes · day-1)b 31.5 ± 15.9* 24.5 ± 13.1c 38.6 ± 21.2* 25.9 ± 15.5d 42.0 ± 22.1* 22.7 ± 13.9 31.6 ± 18.1* 19.5 ± 13.1e
TV (≥ 2 hr · day-1)f (%) 58 56 50 51 63 50 64 52
VG (≥ 1 hr · day-1)f (%) 22 12 42 14 60 32 66 34
  1. Values are presented as mean ± SD.
  2. SD, standard deviation.
  3. a Percentage of body fat determined by DXA scan.
  4. b moderate-to-vigorous physical activity.
  5. c n = 228.
  6. d n = 221
  7. e n = 187.
  8. Response categories: (1) < 1 hr · day-1 or not at all; (2) ≥ 1 hr · day-1 but < 2 hr · day-1; (3) ≥ 2 hr · day-1 but < 3 hr · day-1;
  9. (4) ≥ 3 hr · day-1 but < 4 hr · day-1; and (5) ≥ 4 hr · day-1.
  10. * Age-specific comparison of boys and girls using Student's t-test (p < 0.05).
  11. Age-specific comparison of boys and girls using the Cochran-Armitage trend test (p < 0.05).