1. Faculty of Sport Science, University of Extremadura, Cáceres, Spain
2. Faculty of Sport Science, Physical Activity and Quality of Life Research Group (AFYCAV), University of Extremadura, Cáceres, Spain
3. Departamento de Desporto e Saúde, Escola de Saúde e Desenvolvimento Humano, Universidade de Évora, Évora, Portugal
4. Department of Sport and Physical Education, University of Valencia, Valencia, Spain
5. Development Department, International Tennis Federation, London, UK