Body mass index – proposed norms for children and youths

The aim of the study was to establish normal BMI values vs. age for children and youths having normal body fat content and to confront them with Cole’s cut-off points. In cohorts of 1373 boys and 1805 girls, aged 7–20 years, body fat content was determined from 3 skinfolds (triceps, subscapular, abdominal) using Slaughter’s equations. Next, 1069 boys and 759 girls with acceptable fat percentage (NF groups) were selected and for them log BMI values were computed. Equations of log BMI vs. age (means and SD) computed for NF groups served to present the proposed BMI norms. The obtained upper limits (mean log + 2SD) for boys and girls aged 19 years were 24.6 and 24.5, respectively, and the corresponding body fat contents –23.7 and 24.1, respectively. Inasmuch BMI does not reflect the real body fat content, the presented norms, based on acceptable body fat content, seem to reflect the weight-height relations better than those derived from unselected population data.POST-PUBLICATION NOTICESThe study was partly supported by grants No. AWF-DS.153 of the Polish Ministry of Science and Higher Education. Please note that the order of the authors of this paper should be:  Tomaszewski, Stupnicki, Milde, not  Stupnicki, Tomaszewski, MildePlease note that the e-mail address of the corresponding author is [email protected], not [email protected]

Anaerobic endurance of dance sport athletes

Study aim: To assess the impact of an ordinary training week cycle lasting 6 months on the anaerobic endurance of dance sport athletes

Resistência anaeróbica de jogadores de futebol

Introdução: A resistência anaeróbica, ou seja, a capacidade de realizar séries repetidas de exercícios anaeróbicos na potência máxima é uma característica indispensável para os jogadores de futebol. O objetivo do estudo foi determinar a resistência anaeróbica de jogadores de futebol aplicando repetidos sprints em velocidade máxima. Materiais e Métodos: Um grupo de 14 jogadores de futebol com idades entre 19 e 27 anos foi submetido duas vezes, em janeiro e março, a um teste consistindo de corridas máximas de 6x50m com 15s de intervalo entre as corridas. Os tempos registrados foram convertidos para velocidades. A proporção da velocidade média para a máxima, obtida em todas as seis corridas, ou índice de performance (IP), foi a medida da resistência anaeróbica. Resultados: As velocidades média e máxima foram significativamente maiores em março (5,47±0,25 e 5,67±0,28, respectivamente) com relação a janeiro (5,73±0,31 e 5,97±0,31, respectivamente), apesar de ainda muito baixos. Os valores de IP foram similares nas duas ocasiões (0,960 e 0,965) e não foram correlacionados com as velocidades máximas. Discussão: O método apresentado pode servir como uma ferramenta útil para determinar e classificar atletas no que diz respeito a suas resistências anaeróbicas, aplicando séries repetidas de um exercício específico

Waist-to-height ratio (WtHR): proposed approach to establishing reference values for children and youths

Detection of central obesity is usually based on the criterion represented by the waist-to-height ratio (WtHR)≥ 0.50. However, that criterion has been disputed, especially in the period of growth. Since obesity cannot be reasonably defined without involving body fat content (%F), the aim of the study was to establish gender- and age-specific reference WtHR values for children and youths selected for an acceptable %F. In cohorts of 1193 boys and 1307 girls, aged 7–20 years, body fat content was determined from 3 skinfolds (triceps, subscapular, abdominal) using Slaughter’s equations. Next, 505 boys and 396 girls with acceptable fat percentage were selected and for them log WtHR values were computed. The equations for log WtHR values vs. age (a) were: (–0.31–0.01264a+0.000476a2)±0.0283 for boys and (–0.268–0.02047a+0 .00073a2)±0.0344 for girls. Upper WtHR limits (means +2SD) attained minimum values (0.460 and 0.454) in the age range of 12–15 years. When applying that criterion to subjects with excessive %F, 14.3% of all boys and 18.2% of girls were classified as centrally obese, but only 8.5 and 9.3%, respectively, when the WtHR=0.50 criterion alone was used. Cut-off values for WtHR indicating central obesity are markedly lower than 0.50 especially in the adolescence period and can be applied only to subjects with excessive fat percentage. POST-PUBLICATION NOTICESThe study was partly supported by grants No. AWF-DS.153 and AWF-DM.10 of the Polish Ministry of Science and Higher Education.Please note that the e-mail address of the corresponding author is [email protected], not [email protected]