Univariate analysis for binary exercise exposure variables
| Binary exposure variable | Odds ratio (95% CI) | p Value |
| Grade 1 | ||
| Time period 1 | 1.1 (0.7 to 1.6) | 0.69 |
| Time period 2 | 1.0 (0.7 to 1.5) | 0.93 |
| Grade 2 | ||
| Time period 1 | 1.2 (0.8 to 1.8) | 0.40 |
| Time period 2 | 1.3 (0.9 to 1.8) | 0.18 |
| Grade 3 | ||
| Time period 1 | 1.0 (0.7 to 1.4) | 0.99 |
| Time period 2 | 1.1 (0.8 to 1.5) | 0.77 |
| Walking | ||
| Time period 1 | 1.7 (1.1 to 2.4) | 0.01 |
| Time period 2 | 2.1 (1.5 to 3.0) | <0.001 |
| Lot of exercise | ||
| Age 14 to 19 | 1.5 (1.0 to 2.4) | 0.07 |
| Age 20 to 24 | 1.8 (1.0 to 3.0) | 0.03 |
| Physically active | ||
| Age 14 to 19 | 1.2 (0.8 to 1.9) | 0.39 |
| Age 20 to 24 | 1.0 (0.6 to 1.6) | 1.00 |