Table 1.
Papers involved in the analysis.
| Country | Age group | Mean age | Level | Type of sport | Research method | Number of participants | |
|---|---|---|---|---|---|---|---|
| Baron-Thiene & Alferman (50) | Germany | Adolescent | M = 16.2 (SD = 0.65) | Elite athlete | General (track and field, swimming, and diving in the summer and cross-country skiing, biathlon, and ice skating + basketball, handball, soccer, and volleyball) | Quantitative - questionnaire | 125 |
| Calvo & Topa (51) | Spain | Adolescent | M = 14.3 (SD = 1.6) | Elite athlete | Football | Quantitative - questionnaire | 492 |
| Cervelló et al. (54) | Spain | Adolescent | M = 15.23 (SD/N/A) between 14 and 18 years | Elite athlete | General (mainly tennis) | Quantitative - questionnaire | 134 |
| Consoni et al. (52) | Italy and Spain | Adolescent | N/A (14–18 years) | Non-elite athlete | General | Quantitative - questionnaire | 614 |
| Duda (58) | USA | Young adult | M = 20.97 (SD=N/A) | Non-elite athlete | Basketball, volleyball | Qualitative - interview | 134 |
| Fraser-Thomas et al. (60) | Canada | Adolescent | M = 16.4 (SD = 2.6) + M = 18.3 (SD = 4.1) | Elite athlete | Swimming | Quantitative - questionnaire | 20 |
| Guillet et al. (55) | France | Adolescent | M = 17.06 (SD = 1.32) + M = 15 (SD = 0.81) | Elite athlete | Handball | Quantitative - questionnaire | 723 |
| Le Bars et al. (56) | France | Adolescent | M = 17.9 (SD = 1.3) + M = 16.7 (SD = 1.1) | Elite athlete | Judo | Quantitative - questionnaire | 186 |
| Lea & Branco (53) | Slovenia | Adolescent | M = 14.87 (SD=N/A) | Elite athlete | Athletics (javelin, high jumper, runner, sprinter) | Quantitative - questionnaire | 566 |
| Ryan et al. (59) | USA | Young adult | M = 21 (SD=N/A) | Non-elite athlete | Aerobic, Tae Kwon Do | Qualitative - interview | 40 |
| Sarrazin et al. (57) | France | Adolescent | M = 14.07 (SD = 0.79) | Elite athlete | Handball | Quantitative - questionnaire | 335 |