Gender Effects on Submaximal Energy Expenditure in Children

Abstract

Previous studies have suggested that submaximal energy expenditure relative to body mass during weight-bearing exercise may be greater in boys compared to girls. This two-part study examined a) gender-related five-year longitudinal changes in submaximal walking economy and b) gross, net, and delta muscle work efficiency during submaximal cycle exercise in a cross-sectional analysis of boys and girls. In the longitudinal study, the influence of pre-exercise metabolic expenditure, stride frequency, and substrate utilization (by RER) on changes in economy were examined. During the five years, mean VO2 per kg during submaximal treadmill walking (measured at 8% slope, 3.25 mph) decreased 16% in girls and 13% in boys (p > 0.05 for gender). Likewise, no significant gender differences were observed in decline of stride frequency over time. RER values were similar between sexes except in the final two years when girls had significantly greater values than the boys. No gender-related differences were observed in any measure of muscle work efficiency. This study failed to reveal significant gender differences in utilization of energy during submaximal exercise in children.

Moving on land: an explanation of pedometer counts in children

“…5) from eight studies of a variety of species (mammals, lizards, birds, reptiles). Using the mean values of boys from the study of Rowland (1997) we show that both absolute and relative energy cost of locomotion conform to allometric Eqs. 4 and 5 (Figs.…”

“…We show this relationship empirically in Fig. 2 using mean values from a 5-year longitudinal study of 11 boys (Rowland et al 1997) running on a treadmill. Since speed · time equals distance, we can say that the number of steps to cover a given distance is inversely related to linear dimension.…”

“…2 The stride frequency at a given speed decreases as a function of linear dimension. Data from Rowland et al 1997 Fig. 3 The stride frequency at a given speed decreases as a function of body mass.…”

“…3 The stride frequency at a given speed decreases as a function of body mass. Data from Rowland et al 1997 thereafter, until recently the issue of scaling of _ V O 2 has not been systematically addressed in humans. Nevertheless, the use of ratio standards remains common in exercise science and human physiology.…”

Desempenho em teste cardiopulmonar de adolescentes: peso normal e excesso de peso

“…Nesse sentido, Norman et al 9 Neste estudo, utilizamos a velocidade no LAV (km/h) como variável relacionada à carga de trabalho. Contudo, na literatura são utilizados também outros parâmetros, como: tempo total do teste 19 , distância percorrida em determinado tempo 9 , cálculos para análise de eficiência do trabalho 4,25 , frequência de passada 25 . Nesse sentido, tornou-se difícil a comparação dos resultados deste estudo com os de outros trabalhos em termos de valores, principalmente porque muitos deles avaliaram apenas os valores máximos do teste de esforço, utilizaram o cicloergômetro 5,9,19,20,26 e/ou trabalharam com diferentes protocolos de teste.…”