Table 2.
Presented questions and response types of the retrospective questionnaire.
| Operating factor | Presented question(s) | Response type(s) |
|---|---|---|
| (1) Volume of organised in-club football practice | How much did you practice within the football club in an average week since the start of your career (time of practice, without games)? | Number and total duration (h) of sessions per week, values for each age category |
| (2) Volume of free play within football | How many hours did you spend with free football in an average week (e.g., with colleagues, friends, on your own…)? | Total duration (h) per week, value for each age category |
| (3) Volume of sports activities besides football1 | Please tell us any sport domain (besides football) you practiced on a regular base. How much did you practice within the club in an average week (time of practice, without games)? | Sport domain, number and total duration (h) of sessions per week in each domain, values for each age category |
| How many hours did you spend with any other sporting activity than club practice, free football and physical education in an average week? | Total duration (h) per week, value for each age category | |
| (4) The age at initial football club participation | What was your age at initial football club participation (distinct from age at initial free football participation)? | Age category (y) |
1Sum of two presented questions.