Aerobic fitness is an important health-related fitness component. The objective of this study was to analyze the influence of age, growth, body composition, sexual maturation and socioeconomic status on the aerobic fitness of female school children attending public schools in Cascavel, Paraná, Brazil. A cross-sectional epidemiological study was conducted in 2006 on 1,317 school children aged 8 to 17 years. Body mass, height and triceps and medial calf skinfold thickness were measured and relative body fat (%BF) was calculated. Sexual maturation was self-assessed using a breast development scale (M1 to M5). The questionnaire proposed by the Brazilian Association of Research Companies was used to assess socioeconomic status. Aerobic fitness was estimated by the 20-m shuttle run test. The results were analyzed using two-way ANOVA, Tukey post hoc test, Spearman and Pearson correlation coefficients, and multiple linear regression with 95% confidence intervals. Three variables (age, %BF and socioeconomic status) showed an interaction (p<0.05) in the prediction of VO2peak rel (R2=0.73). All independent variables (body mass, height, age, %BF, socioeconomic status, and sexual maturation) were significant predictors (p<0.05) of VO2pico abs (R2=0.88). In conclusion, chronological age and sexual maturation were the best predictors of VO2peak abs (positive) and VO2peak rel (negative).154448457Ronque, E.R.V., Cyrino, E.S., Dórea, V.R., Serassuelo Jr., H., Galdi, E.H.G., Arruda, M., Diagnóstico da aptidão física em escolares de alto nível socioeconômico: Avaliação referenciada por critérios de saúde (2007) Rev Bras Med Esporte, 13 (2), pp. 71-76Dórea, V., Ronque, E.R.V., Cyrino, E.S., Serassuelo Jr., H., Gobbo, L.A., Carvalho, F.O., Aptidão física relacionada à saúde em escolares de Jequié, BA, Brasil (2008) Rev Bras Med Esporte, 14 (6), pp. 494-499Ball, G.D.C., Shaibi, G.Q., Cruz, M.L., Watkins, M.P., Weigenberg, M.J., Goran, M.I., Insulin sensitivity, cardiorespiratory fitness, and physical activity in overweight Hispanic youth (2004) Obesity Res, 12 (1), pp. 77-85Ulbrich, A.Z., Machado, H.S., Michelin, A., Vasconcelos, I.Q.A., Stabelini, N.A., Mascarenhas, L.P.G., Campos, W., Aptidão física em crianças e adolescentes de diferentes estágios maturacionais (2007) Fit Perf J, 6 (5), pp. 277-282Armstrong, N., Aerobic fitness of children and adolescents (2006) J Pediatr, 82 (6), pp. 406-408Maranhão neto, G.A., Lourenço, P.M.C., Farinatti, P.T.V., Equações de predição da aptidão cardiorrespiratória sem testes de exercício e sua aplicabilidade em estudos epidemiológicos: Uma revisão sistemática (2004) Cad Saúde Pública, 20 (5), pp. 48-56Armstrong, N., Welsman, J., Peak oxygen uptake in relation to growth and maturation in 11 to 17 year-old humans (2001) Eur J Appl Physiol, 85 (6), pp. 546-551Armstrong, N., Welsman Jr, Developmental of aerobic fitness during childhood and adolescence (2000) Pediatr Exerc Sci, 12 (5), pp. 128-149McMurray, R.G., Harrell, J.S., Bradley, C.B., Deng, S., Bangdiwala, S.I., Predicted maximal aerobic power in youth is related to age, gender, and ethnicity (2002) Med Sci Sports Exerc, 34 (1), pp. 145-151Vasques, D.G., Silva, K.S., Lopes, A.S., Aptidão cardiorrespiratória de adolescentes de Florianópolis, SC (2007) Rev Bras Med Esporte, 13 (6), pp. 376-380Santos, D.A., Silva, A.M., Santa-Clara, H., Matias, C.N., Fields, D.A., Sardinha, L.B., Determinant factors of cardiorespiratory fitness in Portuguese adolescents of different ethnicities (2011) Rev Bras Cineantropom Desempenho Hum, 13 (4), pp. 243-249Censo Populacional 2010, , http://www.ibge.gov.br/home/estatistica/populacao/censo2010/ populacao-por-municipio.shtm, Instituto Brasileiro de Geografia e Estatística/IBGE, Available from, [2010 Dec 12]Ross, W.D., Marfell-Jones, M.J., Kinanthropometry (1982) Physiologic Testing of the Elite Canadian Association of Sport Science, pp. 75-115. , Ithaca, Movement PublicationsGordon, C.C., Chumles, W.C., Roche, A.F., (1988) Anthropometric Standardization Reference Manual, pp. 3-8. , Stature, recumbent length, and weight. In: Lohman TG, Roche AF, Martorel R, editorsHarrison, G.G., Buskirk, E.R., Carter, J.E.L., Johnston, F.E., Lohmam, T.G., Pollock, M.L., Skinfold Thickness and Measurement Technique (1988) Anthropometric Standardization Reference Manual, pp. 55-70. , Champaign, IL, Human KineticsSlaughter, M.H., Lohman, T.G., Boileau, R.A., Hoswill, C.A., Stillman, R.J., van Loan, M.D., Bemben, D.A., Skinfold equations for estimation of body fatness in children and youth (1988) Hum Biol, 60 (5), pp. 709-723Léger, L., Boucher, R., An indirect continuous running multistage field test: The Université de Montreal track test (1980) Can J Sports Sci, 5 (2), pp. 77-84Silva, A.C., Torres, F.C., Ergoespirometria em atletas paraolímpicos brasileiros (2002) Rev Bras Med Esporte, 8 (3), pp. 107-116Léger, L., Mercier, D., Gadoury, C., Lambert, J., The multistage 20 meter shuttle run test for aerobic fitness (1988) J Sports Sci, 6 (2), pp. 93-101Guedes, D.P., Guedes, J.E.R.P., (2006) Manual Prático Para Avaliação Em Educação Física, , Manole, BarueriDados Com Base No Levantamento Socioeconômico - 2000, , http://www.abep.org, Associação Brasileira de Empresas de Pesquisa - ABEP, Available from, [2006 Feb 10]Marshall, W.A., Tanner, J.M., Variations in the pattern of pubertal changes in girls (1969) Arch Dis Child, 44 (235), pp. 291-303Bim, R.H., Nardo Jr., N., Aptidão física relacionada à saúde de adolescentes estagiários da Universidade Estadual de Maringá (2005) Acta Sci Health Sci, 27 (1), pp. 77-85Bodas, A.R., Leite, T.M., Carneiro, A.L.G., Gonçalves, P.O., Silva, A.J., Reis, V.M., A influência da idade e da composição corporal na resistência, flexibilidade e força em crianças e jovens (2006) Fit Perf J, 5 (3), pp. 155-160Armstrong, N., Welsman, J., Nevill, A.M., Kirby, B.J., Modeling growth and maturation changes in peak oxygen uptake in 11-13 yr olds (1999) J Appl Physiol, 87 (6), pp. 2230-2236Böhme, M.T.S., Resistência aeróbia de jovens atletas mulheres com relação à maturação sexual, idade e crescimento (2004) Rev Bras Cineantropom Desempenho Hum, 6 (2), pp. 27-35Kristensen, P.L., Wedderkopp, N., Moller, N.C., Andersen, L.B., Bai, C.N., Froberg, K., Tracking and prevalence of cardiovascular disease risk factors across socio-economic classes: A longitudinal substudy of the European Youth Heart Study (2006) BMC Public Health, 27, pp. 6-20Saito, M.I., Maturação sexual: Autoavaliação do adolescente (1984) Pediat, 6, pp. 111-115Ruiz, J.R., Castro-Pinero, J., Espana-Romero, V., Artero, E.G., Ortega, F.B., Cuenca, M.M., Field-based fitness assessment in young people: The ALPHA health-related fitness test battery for children and adolescents (2011) Br J Sports Med, 45 (6), pp. 518-524