Table 1.
Baseline sample characteristics of the National Runners' and Walkers' Health Study participants (percent or mean±SD)
| MET-hours/wk | <7.5 | 7.5 to 12.5 | 12.6 to 25.1 | ≥25.2 |
| Sample size (N) | 9380 | 6389 | 25516 | 50535 |
| Males (%) | 37.20 | 40.29 | 51.60 | 62.52 |
| Walkers (number, (%)) | 4657 (49.65%) | 3004 (47.02%) | 5817 (22.80%) | 2456 (4.86%) |
| Age (years) | 49.96±13.92 | 48.93±13.18 | 47.01±12.03 | 44.04±11.13 |
| Education (years) | 15.82±2.60 | 16.11±2.56 | 16.33±2.47 | 16.34±2.45 |
| Baseline smokers (number, (%)) | 334 (3.56%) | 163 (2.55%) | 505 (1.98%) | 677 (1.34%) |
| Ex-smokers (number, (%)) | 3,344 (35.65%) | 2,246 (34.74%) | 9,224 (36.15%) | 17,557 (35.15%) |
| Pack years smoked | 5.61±14.41 | 4.88±12.67 | 5.20±12.64 | 4.87±11.96 |
| Hypertensive medication users (number, (%)) | 1262 (13.51%) | 665 (10.41%) | 1865 (7.31%) | 1922 (3.80%) |
| Diabetes medication users (number, (%)) | 255 (2.73%) | 101 (1.58%) | 251 (0.98%) | 239 (0.47%) |
| Red meat (servings/d) | 0.42±0.38 | 0.40±0.36 | 0.39±0.36 | 0.34±0.35 |
| Fruit (pieces/d) | 1.42±1.08 | 1.50±1.09 | 1.53±1.10 | 1.66±1.19 |
| Alcohol (g/d) | 5.96±10.46 | 6.71±10.63 | 8.14±11.82 | 8.47±12.53 |
| BMI (kg/m2) | 25.74±5.20 | 24.81±4.13 | 23.83±3.26 | 22.68±2.62 |
| Waist circumference (cm) | 83.44±12.95 | 81.70±11.82 | 80.18±10.51 | 78.22±9.40 |
Men and women who were recruited between 1991 and 1993 (7.7 yr follow-up of 42,833 subjects) and between 1998 and 1999 (6.4 yr follow-up of 33,053 subjects) as part of the National Runners' Health Study and between 1998 and 1999 as part of the National Walkers Health Study (5.7 yr follow-up of 15,934 subjects). All trends significant at P<10−15.