The effect of summer holidays on body composition and respiratory muscle strength in pubescent swimmers / El efecto de las vacaciones de verano sobre la composición corporal y la fuerza muscular respiratoria en nadadores púberes

Changes in daily routine and decrease in physical activity during summer holidays period, often result in body weight gain in school-age children. However, the impact of summer break on body composition in athlete children has not been thoroughly investigated. The current study was aimed at identifying possible changes in body composition and respiratory muscle strength after an 8-week summer break in age-group swimmers. Eighteen girls and fifteen boys ages 10-13 years (mean 11.6±1.0) participated in the study. The measurements were taken in June and repeated in September the same year. Body composition was assessed with an InBody 720 analyzer, and respiratory muscle strength was assessed with a MicroRPM device. A fifty-meter front-crawl test was conducted to induce respiratory muscle fatigue. All analyzed body composition parameters; i.e., body mass, body mass index, tissue, and muscle components increased substantially after the summer break (p<0.05). No significant changes in maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP) were detected in both boys and girls after the detraining period (p>0.05). It can be concluded that 8-week summer break had an effect on body composition parameters in juvenile swimmers, but no effect on their respiratory muscle strength was apparent. Studies involving a greater number of participants engaged in various sports activities are needed to better understand the effect of summer break on anthropomorphic and respiratory parameters in youth athletes. (AU)

Los cambios en la rutina diaria y la disminución de la actividad física durante el periodo de vacaciones de verano, suelen provocar un aumento de peso corporal en los niños en edad escolar. Sin embargo, no se ha investigado a fondo el impacto de las vacaciones de verano en la composición corporal de los niños deportistas. El presente estudio tenía como objetivo identificar los posibles cambios en la composición corporal y la fuerza muscular respiratoria tras unas vacaciones de verano de 8 semanas en nadadores jovenes. Dieciocho niñas y quince niños de 10 a 13 años (media de 11.6±1.0) participaron en el estudio . Las mediciones se realizaron en junio y se repitieron en septiembre del mismo año. Se evaluó la composición corporal con un analizador InBody 720 y la fuerza muscular respiratoria con un dispositivo MicroRPM. Se realizó una prueba de crol frontal de cincuenta metros para inducir la fatiga de los músculos respiratorios. Todos los parámetros de composición corporal analizados, es decir, la masa corporal, el índice de masa corporal, el tejido y los componentes musculares, aumentaron sustancialmente tras el descanso estival (p<0.05). No se detectaron cambios significativos en la presión inspiratoria máxima (MIP) ni en la presión espiratoria máxima (MEP) tanto en los chicos como en las chicas después del periodo de desentrenamiento (p>0.05). Se puede concluir que las vacaciones de verano de 8 semanas tuvieron un efecto sobre los parámetros de composición corporal en los nadadores juveniles, pero no se observó ningún efecto sobre su fuerza muscular respiratoria. Se necesitan estudios con un mayor número de participantes que practiquen diversas actividades deportivas para comprender mejor el efecto de las vacaciones de verano en los parámetros antropomórficos y respiratorios de los deportistas juveniles. (AU)

Reduction of Skeletal Muscle Power in Adolescent Males Carrying H63D Mutation in the HFE Gene.

Iron overload resulting from the mutation of genes involved in iron metabolism or excess dietary intake has been reported to negatively influence human physical performance. The aim of this study was to test the hypothesis that adolescents bearing a hemochromatosis gene (HFE) mutation in contrast to adults with the same mutation will not experience iron accumulation and their aerobic capacity will be similar to that of age-matched controls. Thirteen boys participated in the study. Seven of them are carriers of H63D mutation in the HFE gene and six were wild type. Fitness levels were assessed using the cardiopulmonary exercise test. In addition, iron status and inflammatory markers were determined. We observed that cardiovascular fitness was significantly lower in the group bearing the HFE mutation compared to the control group. Moreover, the HFE mutation group achieved lower maximal power output compared to the control group. There were no differences in blood ferritin concentrations between the two groups which indicates similar amounts of stored iron. Obtained data do not confirm our hypothesis. On the contrary, it was demonstrated that HFE mutation is associated with a lower level of aerobic capacity, even in the absence of iron accumulation.