Relationships between the duration of physical activity per week and potential confounding factors
| Usual duration of exercise | ||||
|---|---|---|---|---|
| <1 h/week(n = 2138) | 1–3 h/week(n = 2189) | >3 h/week(n = 831) | p Value* | |
| Values are expressed as percentages except where indicated otherwise. | ||||
| BMI, body mass index; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity. | ||||
| *Using analysis of variance test for continuous variables or χ2 test for categorical variables. | ||||
| †FEV1 = residual FEV1 +FEV1 mean. | ||||
| ‡Mean (SD). | ||||
| Men (%) | 46.9 | 51.4 | 60.1 | <0.001 |
| Women (%) | 53.1 | 48.6 | 39.9 | |
| Age (%) | ||||
| <40 years | 37.0 | 38.4 | 40.7 | 0.13 |
| 40–50 years | 41.9 | 42.6 | 42.0 | |
| >50 years | 21.1 | 19.1 | 17.3 | |
| Age when finished education (%) | ||||
| ⩽16 years | 22.1 | 13.0 | 14.6 | <0.001 |
| 17–21 years | 36.7 | 35.0 | 37.8 | |
| >21 years | 41.2 | 52.0 | 47.6 | |
| BMI (%) | ||||
| <25 kg/m2 | 51.2 | 53.6 | 50.4 | |
| 25–30 kg/m2 | 34.7 | 35.9 | 38.5 | |
| >30 kg/m2 | 14.1 | 10.5 | 11.1 | 0.003 |
| Smoking (%) | ||||
| Never smokers | 40.6 | 46.1 | 44.8 | <0.001 |
| Past smokers | 22.6 | 25.5 | 28.5 | |
| Moderate smokers | 21.2 | 20.2 | 18.3 | |
| Heavy smokers | 15.6 | 8.2 | 8.4 | |
| Atopy (%) | 27.1 | 28.6 | 31.6 | 0.07 |
| Asthma-like symptoms (%) | 24.8 | 22.8 | 26 | 0.11 |
| Current asthma (%) | 5.0 | 4.5 | 5.5 | 0.55 |
| Family history of asthma (%) | 10.8 | 11.5 | 10.1 | 0.51 |
| FEV1 (l)†‡ | 3.59 (0.45) | 3.59 (0.45) | 3.63 (0.48) | 0.076 |
| FEV1 (% pred)‡ | 107 (14) | 107 (13) | 108 (14) | 0.097 |
| FVC (% pred)‡ | 111 (14) | 111 (14) | 112 (14) | 0.072 |