Baseline characteristics
| All participants | Intervention group | Control group | ||||
| N | %/Mean (SD) | N | %/Mean (SD) | N | %/Mean (SD) | |
| N | 2378 | 1196 | 50.3% | 1182 | 49.7% | |
| Demographics | ||||||
| Gender (male) | 1252 | 52.6% | 623 | 52.1% | 629 | 53.2% |
| Age (years) | 41.2 (11.9) | 41.0 (11.7) | 41.4 (12.0) | |||
| BMI (kg/m2) | 23.7 (2.9) | 23.6 (2.9) | 23.7 (2.8) | |||
| Training | ||||||
| Running experience (years) | 6.5 (7.8) | 6.6 (7.9) | 6.4 (7.8) | |||
| Running frequency per week | 2.5 (1.5) | 2.5 (1.5) | 2.5 (1.4) | |||
| Running time per week (hours) | 3.1 (3.3) | 3.1 (3.3) | 3.1 (3.3) | |||
| Running distance per week (km) | 22.2 (19.0) | 22.3 (19.0) | 22.1 (19.0) | |||
| Training speed (min/km) | 6:04 (1:07) | 6:03 (1:07) | 6:05 (1:07) | |||
| Type of training (%) | ||||||
| Endurance training | 68.6 (24.1) | 68.5 (24.2) | 68.8 (23.9) | |||
| Interval training | 23.9 (20.9) | 24.2 (21.2) | 23.6 (20.6) | |||
| Exercises | 7.4 (10.4) | 7.3 (9.7) | 7.8 (11.0) | |||
| Member of athletic association (yes) | 715 | 30.1% | 352 | 29.4% | 363 | 30.7% |
| Running event | ||||||
| Distance registered for:* | ||||||
| 5/7.5 km | 139 | 5.8% | 75 | 6.3% | 64 | 5.4% |
| 10/10.55 km | 905 | 38.1% | 440 | 36.8% | 465 | 39.3% |
| Half-marathon | 711 | 29.9% | 367 | 30.7% | 344 | 29.1% |
| Marathon | 625 | 26.3% | 317 | 26.5% | 308 | 26.1% |
| Participated in a running event before (yes) | 2168 | 91.2% | 1092 | 91.3% | 1076 | 91.0% |
| Average participations per year | 4.2 (5.1) | 4.2 (4.7) | 4.2 (4.9) | |||
| Lifestyle | ||||||
| Smoking (yes) | 107 | 4.5% | 57 | 4.8% | 50 | 4.2% |
| Alcohol use (glasses per week) | 4.2 (4.8) | 4.1 (4.7) | 4.3 (4.9) | |||
| Previous RRIs | ||||||
| Previous RRI in previous 12 months (yes) | 1238 | 52.1% | 611 | 51.1% | 627 | 53.0% |
| Reported RRI at baseline (yes) | 540 | 22.7% | 281 | 23.5% | 259 | 21.9% |
*Running distance was missing for two participants, while two participants registered for two and one participant for three running distances of one running event.
BMI, body mass index; RRI, running-related injury.