Anthropometric And Metabolic Profile Of 13 Year-old Adolescents In Different Levels Of Sexual Maturation

Introduction
there is little information about physical fitness level in adolescents during puberty at the same chronological age but at
different sexual maturation levels.
Purpose: to analyze anthropometric and metabolic variables of physical fitness among adolescents in puberty at same
chronological age (13 years old), in different sexual maturation stages.

Methods
sample consisted of 79 males 13 years old (13.48 ± 0.28 y) from the Ilhabela public school. Ilhabela is an island of low
socio economic status in Sao Paulo coast of Brazil. This group is part of the Longitudinal Project of Growth,
Development and Physical Fitness developed by CELAFISCS since 1978. The maturation level was established
through the self-assessment of Tanner stages [1], considering pubic hair and genital development. A trained physician
classified axillary hairs in three stages: I (pre-puber), II (puberty), and III (post-puber). All of them were in puberty
according to Tanner pubic hair and genital stages (II, III and IV). The anthropometric variables measured were: body
weight (BW), body height (BH), body adiposity determined through the mean of seven skinfolds. Aerobic power
(VO2max) was determined by a submaximal cycle ergometer test using Astrand Nomogram. Values were expressed in
relative (ml.kg.min-1) and absolute terms (l.min-1). Results were analyzed by One Way ANOVA, post-hoc Scheffé, and
delta percent (%Δ). Level of significance adopted was p<.05.

Results
Physical fitness values in mean (x) and standard deviation (s) according to sexual maturation stages are summarized inthe table as follows:
According to pubic hair stages, data showed significant increase in BW from stage II to III (25.9%) and from stage II to
IV (24.4%); in BH from stage II to III (5%), and from II to IV (5.4%). Data of adiposity and aerobic power did not
show any significant differences among the stages of sexual maturation (pubic hair, genital and axillary’s hair
development).

Discussion
previous studies have shown that there is an increase of lean mass in relation to fat mass during the puberty in male
adolescents [2]. Thus, its explains there were not differences in the adiposity, although it happened in body weight and
height. Former studies using data of this specific population of Ilhabela adolescents, showed a stability of functional
maturation of aerobic power in this sample at the age of 13 years, confirming the results of this study [3].

Conclusion
analyzing the different maturational stages through axillary hair and genital development, there were differences on
body height and weight but no significant differences in adiposity or aerobic power were found. Data suggest during
puberty is possible to find differences in physical fitness level among adolescents at a same chronological age but in
different sexual maturation stages. Thus, it reinforces the idea that to have a better diagnosis and prognosis of the fitness
level, and exercise prescription of adolescents, professionals need to consider also their sexual maturation
development.

References
[1]. Matsudo S. and Matsudo V. (1994) Self-Assessment and Physician Assessment of Sexual Maturation in Brazilian
Boys and Girls: Concordance and Reproducibility. American Journal of Human Biology 6:451-455.
[2]. Malina, R.M. and Bouchad, C. (1991) Growth, Maturation, and Physical Activity. Models and Methods for
Studying Body Composition, Human kinetics. Champaing, IL.
[3]. Andrade, D.R. et al. (1993) Modelo Biológico para Diagnótico da Salud y Prescripción de Actividad Física.
Archivos de Medicina del Esporte, X (37): 35-48.

NOTA: O texto com a iconografia está no anexo

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