Physical fitness mediates the inverse association between fatness indicators and academic achievement, despite the school vulnerability of adolescents-The Cogni-Action Project.

Objective: This study aims to determine the mediating role of physical fitness in the relationship between fatness indicators and academic achievement, exploring the influence of school vulnerability. Methods: A total of 1,296 Chilean adolescents (aged 10 to 14 years; 50% girls) participated in this study. The global fitness score (GFS) was obtained by adding the three main components of the ALPHA fitness test: cardiorespiratory fitness (CRF), muscular fitness (MF), and speed/agility fitness (SAF). CRF was evaluated through the 20 m shuttle run test; MF by upper and lower limb strength tests; and SAF by the 4 × 10 shuttle run test. BMIz and WHtR were evaluated as general (unspecific) and central (specific) fatness indicators. Academic achievement was established through grades in math, language, and science and their average scores. Multiple mediation analyses were performed according to two models, adjusted for sex, maturity, and schools (model 1), and in model 2, the school vulnerability index (SVI) was added. The SVI is an important proxy of socioeconomic status at the school level, and it was categorized as high-, mid-, or low-SVI. Mediation percentages were calculated, and confidence intervals (bootstrapping) were used to establish significant findings. Results: CRF, SAF, and GFS mediate the relationship between fatness indicators and academic achievement, both partially and totally (ranging from 12.7 to 59.2%). However, MF did not show any mediation effect. After controlling for SVI, CRF, and GFS, mediation changed from partial to total in the associations between math and science with WHtR. Although SAF contributed to GFS mediation, CRF seems to have the most significant mediation role for all academic achievements, regardless of SVI and the fat indicator studied. Conclusion: A higher level of general physical fitness, especially CRF, significantly mediates the detrimental influence of fatness on the academic achievement of schoolchildren. This study suggests that physical fitness plays a relevant role in academic and public health, considering the high prevalence and detrimental influence of obesity and school vulnerability in children and adolescents.

Which one? A comparative study of traditional and sports uniforms on academic achievement, cognitive performance, playtime, bullying, and discrimination in adolescents: The Cogni-Action Project.

Objective: The aim of this study was to compare academic achievement, cognitive performance, playtime, bullying, and discrimination in adolescents according to traditional uniforms (TUs) and sports uniforms (SUs) worn at school, while simultaneously exploring the influence of the school vulnerability index. Methods: A total of 988 Chilean adolescents (52.6% boys) aged 10-14 years participated in this cross-sectional study. Academic achievement was evaluated by the average grade in maths, language, and science grades, while cognitive performance was assessed through eight cognitive tasks. TUs affecting physical activity, playtime, bullying, and discrimination were queried. Mixed model analyses were performed. Results: No differences were observed in academic achievement (TU: 5.4 ± 0.1 vs. SU: 5.5 ± 0.2, p = 0.785) or in cognitive performance (TU: 99.6 ± 0.8 vs. SU: 98.9 ± 1.8, p= 0.754) according to the school uniformtype. Moreover, 64.1 % of participants declared that wearing TU affects their physical activity (traditional uniforms: + 8 min and sports uniforms: + 20 min), and those who believed so spent more time playing than those who answered negatively (14.5 min, p = 0.012). Finally, adolescents wearing SU displayed a lower feeling of bullying and discrimination; this finding depended mainly on the school's vulnerability. Conclusion: It is concluded that wearing TU does not show an educational advantage at an academic and cognitive level that justifies its obligation. In addition, it could be suggested that schools consider adolescents' opinions in adopting a more comfortable uniform, such as the SU. This feasible and low-cost measure would help to increase adolescents' physical activity during the school day, and, contrary to belief, it would not be related to increased feelings of bullying and discrimination.

Composición corporal, parámetros bioeléctricos y fuerza de prensión manual en escaladores chilenos federados y recreativos / Body composition, bioelectrical parameters, and handgrip strength in federated and recreational Chilean climbers

RESUMEN: El objetivo del siguiente estudio fue determinar y comparar los valores de composición corporal, parámetros bioeléctricos y fuerza de prensión manual de escaladores chilenos federados y recreativos. Participaron voluntariamente 13 escaladores chilenos, de los cuales 4 eran federados (25,75 ± 2,87 años) y 9 recreativos (22,33 ± 1,41 años). La composición corporal se evaluó por medio de un impedanciómetro bioeléctrico octopolar multifrecuencia, mientras que la fuerza de prensión manual se determinó con un dinamómetro manual. Si bien no hubo diferencias en las variables de composición corporal entre ambos grupos, el ángulo de fase del tronco fue superior en los federados en comparación a los recreativos (p = 0,011 [95 % IC = 1,10; 5,20]). Respecto a la fuerza de prensión manual, la fuerza relativa fue superior para los federados (p = 0,025 [95 % IC = 0,10; 0,22]), mientras que la diferencia de la fuerza entre la mano dominante y no dominante fue mayor para los recreativos (p = 0,012 [95 % IC = 1,60; 10,05]). Este es uno de los primeros estudios que explora las diferencias entre escaladores chilenos federados y recreativos. Los resultados sugieren una diferenciación a nivel de ángulo de fase y fuerza de prensión manual, lo cual debería corroborarse con futuros estudios.

SUMMARY: This study aimed to determine and compare the body composition, bioelectric parameters, and handgrip strength in federated and recreational Chilean climbers. Thirteen Chilean climbers voluntarily participated, being 4 federated (25.75 ± 2.87 years) and 9 recreational (22.33 ± 1.41 years). Body composition was measured using a multifrequency octopolar bioelectrical impedance meter, while handgrip strength was determined with a dynamometer. Although there were no statistical differences in the body composition variables between groups, the trunk phase angle was statistically higher in the federated compared to the recreational climbers (p = 0,011 [95 % CI = 1,10; 5,20]). Regarding handgrip strength, the relative strength was higher for federated (p = 0,025 [95 % CI = 0,10; 0,22]), while the difference in strength between dominant and non-dominant hand was higher for recreational climbers (p = 0,012 [95 % CI = 1,60; 10,05]). This study is one of the first that explore the differences between federated and recreational Chilean climbers. These results suggest a differentiation at the level of phase angle and handgrip strength, which should be corroborated in future studies.