Table 1.
Baseline characteristics of the children as means and standard deviations (SD) or frequencies.
| Girls | Boys | Total | ||||
|---|---|---|---|---|---|---|
| Variable | n | M (SD)/% | n | M (SD)/% | n | M (SD)/% |
| Age (years) | 541 | 10.2 (0.3) | 588 | 10.2 (0.3) | 1,129 | 10.2 (0.3) |
| BMI | 531 | 18.1 (3.0) | 564 | 18.0 (3.0) | 1,095 | 18.1 (3.0) |
| Body fat (mm) | 527 | 58.4 (29.3) | 557 | 42.2 (20.9)*** | 1,084 | 50.1 (26.6) |
| Pubertal stage (Tanner) (%) | 526 | 555 | 1,081 | |||
| Stage 1 | 116 | 21.4 | 193 | 32.8*** | 309 | 27.4 |
| Stage 2 | 345 | 63.8 | 303 | 51.5 | 648 | 57.4 |
| Stage 3, 4, and 5 | 65 | 12.2 | 59 | 10.0 | 124 | 11.0 |
| Socio economic status (%) | 511 | 558 | 1,049 | |||
| ≤ Upper secondary school | 156 | 28.8 | 193 | 32.8 | 349 | 30.9 |
| <4 years of university/college | 156 | 28.8 | 164 | 27.9 | 320 | 28.3 |
| ≥4 years of university/college | 199 | 36.8 | 201 | 34.2 | 400 | 35.4 |
| PA-levels (full day) | ||||||
| Counts per minute (cpm) | 484 | 691 (236) | 521 | 773 (299)*** | 1,005 | 733 (274) |
| SED (% all day) | 484 | 60.2 (5.9) | 522 | 59.5 (6.5) | 1,006 | 59.8 (6.2) |
| MVPA (% all day) | 484 | 8.9 (2.7) | 522 | 10.5 (3.5)*** | 1,006 | 9.7 (3.3) |
| Aerobic fitness (m) | 511 | 868.6 (85.8) | 534 | 915.9 (112.6)*** | 1,045 | 893.8 (103.1) |
| Estimated VO2peak (ml/kg/min) | 510 | 48.9 (6.9) | 534 | 55.2 (7.3) | 1,044 | 52.3 (8.0) |
| Motor skills | ||||||
| Shuttle Run (s) | 527 | 23.6 (2.2) | 556 | 22.7 (2.3)*** | 1,083 | 23.1 (2.5) |
| Aiming (n) | 532 | 3.8 (1.9) | 561 | 4.2 (1.9)*** | 1,093 | 4.0 (1.9) |
| Catching (n) | 507 | 3.3 (2.9) | 526 | 4.8 (3.1)*** | 1,033 | 4.1 (3.1) |
| Executive function | ||||||
| Stroop CW (n) | 525 | 26.6 (5.8) | 563 | 25.1 (6.0)*** | 1,088 | 25.8 (5.9) |
| Verbal Fluency (n) | 528 | 16.0 (4.6) | 567 | 16.0 (4.7) | 1,095 | 16.0 (4.6) |
| WISC-IV backward (n) | 526 | 6.3 (1.4) | 567 | 6.1 (1.3)** | 1,093 | 6.2 (1.3) |
| TMT-b (s) | 512 | 114.9 (40.8) | 529 | 128.6 (53.3)*** | 1,051 | 121.9 (48.1) |
| Academic performance | ||||||
| Numeracy | 518 | 50.3 (8.9) | 562 | 52.1 (9.9)*** | 1,080 | 51.3 (9.5) |
| Reading | 513 | 49.7 (9.4) | 553 | 49.2 (10.0) | 1,066 | 49.4 (9.7) |
| English | 515 | 48.6 (9.0) | 547 | 50.1 (10.5)* | 1,062 | 49.4 (9.8) |
BMI, body mass index; PA, physical activity; SED, sedentary time; MVPA, moderate-to-vigorous physical activity; Stroop CW, Stroop Color Word; WISC-IV, Wechsler Intelligence Scale for Children fourth edition; TMT-b, Trail Making Test part B.
*
p ≤ 0.05 for the difference between girls and boys;
**
p ≤ 0.010 for the difference between girls and boys;
***
p ≤ 0.001 for the difference between girls and boys.