Table 3: Descriptive statistics of dependent variables.
aPA1: physical activity < 839.99 METs-min/wk; bPA2: physical activity 840-1559.99 METs-min/wk; cPA3: physical activity > 1560 METs-min/wk.
| Variables | All | Boys | Girls |
| Mean | SD | Mean | SD | Mean | SD |
| PA (METs-minutes/week) | 1981.6 | 2934.4 | 2415.4 | 3492.2 | 1524.0 | 2106.3 |
| PA1a | 0.43 | 0.50 | 0.35 | 0.48 | 0.52 | 0.50 |
| PA2b | 0.19 | 0.39 | 0.18 | 0.39 | 0.20 | 0.40 |
| PA3c | 0.37 | 0.48 | 0.47 | 0.50 | 0.28 | 0.45 |
| Age | 13.34 | 0.95 | 13.34 | 0.94 | 13.33 | 0.96 |
| Paternal BMI | 24.30 | 9.98 | 24.56 | 13.53 | 24.04 | 3.56 |
| Maternal BMI | 21.87 | 3.61 | 21.89 | 3.62 | 21.84 | 3.61 |
| Tutor class | 0.62 | 0.49 | 0.60 | 0.49 | 0.63 | 0.48 |
| Father working | 0.90 | 0.31 | 0.88 | 0.32 | 0.91 | 0.28 |
| Mother working | 0.71 | 0.46 | 0.68 | 0.47 | 0.72 | 0.45 |
| Siblings | 0.90 | 0.30 | 0.89 | 0.31 | 0.90 | 0.29 |
| Living with parents | 0.88 | 0.33 | 0.87 | 0.33 | 0.88 | 0.33 |
| Income | 0.21 | 0.41 | 0.21 | 0.40 | 0.20 | 0.40 |
| Allowance | 0.70 | 0.46 | 0.67 | 0.47 | 0.73 | 0.44 |
| Reasons for PA |
| Active lifestyle | 0.29 | 0.45 | 0.34 | 0.47 | 0.23 | 0.42 |
| Accompaniment | 0.33 | 0.47 | 0.31 | 0.47 | 0.34 | 0.48 |
| Fun | 0.61 | 0.49 | 0.73 | 0.44 | 0.55 | 0.50 |
| Spend time | 0.44 | 0.50 | 0.49 | 0.50 | 0.39 | 0.49 |
| N | 1165 | 597 | 567 |