A total of 522 volleyball players participating in the High School Olympic Games of the State of São Paulo (Brazil) were approached (249 females and 273 males; mean age: 14.96 ± 1.67 years; body mass: 60.88 ± 12.43 kg; height: 1.69 ± 0.11 m; body mass index (BMI): 21.08 ± 2.81 kg · m-2; and duration of training: 3.24 ± 1.68 years). The volunteers were classified as young (aged 12 to 18 years), based on the classification determined in the Brazilian Child and Adolescent Statute established in Brazil in 1990 [13].The volunteers and their respective parents/guardians were informed as to the purpose of the study, agreed to participate and signed a statement of informed consent. The study received approval from the Human Research Ethics Committee of the Universidade Estadual Paulista/Faculdade de Ciências e Tecnologia (Brazil) under protocol number 221/2007.