Table 1. Characteristics of participants in the study aged 8 to 17-yr-old .
| Continuous variables | Total (n=177,091) | Boys (n=87,803) | Girls (n=89,288) | P value | |||
| Mean | SD | Mean | SD | Mean | SD | ||
| Age (yr) | 9.88 | 2.8 | 9.91 | 2.8 | 9.84 | 2.8 | 0.001 |
| Body Mass Index, (Kg/m2) | 19.7 | 3.8 | 19.8 | 3.8 | 19.5 | 3.7 | 0.001 |
| Waist circumference, (cm) | 70.4 | 10.7 | 71.6 | 11.1 | 69.2 | 10.2 | 0.001 |
| KIDMED score, (0, 12) | 6.7 | 2.4 | 6.7 | 2.4 | 6.8 | 2.4 | 0.001 |
| Physical activity, (h/wk) | 9.4 | 5.5 | 10.4 | 5.9 | 8.4 | 5.2 | 0.001 |
| Screen time, (h/wk) | 8.6 | 8.5 | 9.3 | 8.8 | 7.8 | 7.8 | 0.001 |
| Sleeping time, (h/d) | 8.6 | 1.6 | 8.6 | 1.6 | 8.6 | 1.6 | 0.565 |
| 20m shuttle run, (laps) | 31.1 | 18.6 | 36.2 | 20.6 | 25.4 | 13.9 | 0.001 |
| Standing long jump, (cm) | 117.0 | 55.7 | 124.0 | 59.3 | 110.0 | 50.5 | 0.001 |
| Sit and reach, (cm) | 15.4 | 8.3 | 13.2 | 7.6 | 17.7 | 8.3 | 0.001 |
| Sit-Ups in 30 seconds, (n/30s) | 19.7 | 5.7 | 20.6 | 5.8 | 18.7 | 5.3 | 0.001 |
| 10X5-meter shuttle run, (sec) | 21.5 | 3.4 | 21.0 | 3.4 | 22.1 | 3.3 | 0.001 |
| Dichotomous variables | Number | Percent | Number | Percent | Number | Percent | P value |
| Children (8-12 yr) | 128,134 | 72.5 | 65,161 | 50.9 | 62,973 | 49.1 | 0.001 |
| Adolescents (13-17 yr) | 48,975 | 27.5 | 25,660 | 52.5 | 23,315 | 47.5 | 0.001 |
| Achieved 60 min/day MVPA | 102,632 | 58.0 | 57,130 | 65.1 | 42,294 | 50.7 | 0.001 |
P values for differences between boys and girls; MVPA: Moderate to vigorous physical activity (current recommendations for PA)