Characteristics of the participants at baseline
| Total | No MHS | MHS | |
| No of participants (%) | 573 | 250 (44) | 323 (56) |
| Age (years) | 25.9±4.4 | 25.6±4.5 | 26.2±4.2 |
| Height (cm) | 184.9±8.7 | 184.9±8.7 | 185.0±8.8 |
| Weight (kg) | 101.5±14.6 | 100.5±14.0 | 102.1±15.1 |
| Duration professional football career (years) | 6.0±4.0 | 6.0±4.0 | 6.1±4.0 |
| Level of play (highest level, %) | 74 | 70 | 77 |
| Field position % | |||
| Forward | 62 | 59 | 65 |
| Back | 38 | 41 | 35 |
| International % | 55 | 60 | 51 |
| Educational level % | |||
| No school completed | 1 | 2 | 1 |
| High school | 39 | 37 | 41 |
| Vocational/technical school | 8 | 7 | 9 |
| College, university or equivalent | 51 | 54 | 48 |
| Family history of mental health % | 11 | 8 | 13 |
| Baseline prevalence % | |||
| Distress | 20 | – | 35 |
| Anxiety/depression | 32 | – | 56 |
| Sleep disturbance | 12 | – | 22 |
| Adverse alcohol use | 15 | – | 27 |
| Eating disorder | 22 | – | 39 |
| Injury | 56 | 54 | 57 |
| Concussion | 35 | 28 | 40 |
Values are mean±SD unless otherwise stated.
Level of play (highest level, %) states only the percentage of players competing at the highest level (not second highest level and lower).
MHS, mental health symptoms.