Abstract Objective. To analyze the self-esteem of Chilean students from public schools and determine its association with sleep hygiene variables, after the first year of restrictions due to the COVID-19 pandemic. Method. The study had a non-experimental, descriptive, and analytical design, with a cross-sectional temporal dimension. A convenience non-probabilistic sample of 265 students from 7th to 12th grade (between 11 and 18 years old) of both sexes from the town of El Carmen, southern Chile, participated in an online questionnaire about context, self-esteem, and sleep habits. Analysis of results. A majority of students perceived themselves with average or low self-esteem (26.4% and 24.9%, respectively). It was found that students who usually fell asleep before midnight, did not wake up tired or did so occasionally, did not have nightmares, and did not usually have trouble falling asleep had higher self-esteem than those who fell asleep after midnight, woke up tired regularly, had nightmares, and had trouble falling asleep, respectively. Conclusions. It was concluded that a high percentage of students had average or low self-esteem, and that students who reported having better sleep hygiene had higher self-esteem compared to those who had worse sleep hygiene. In this way, further studies are necessary to address these topics, especially in contexts of uncertainty, where it is presumed that they could have an impact on both lifestyle habits and mental health.

Resumen Objetivo. Analizar la autoestima de estudiantado chileno de colegios públicos y determinar su asociación con variables de higiene del sueño, luego del primer año de restricciones por la pandemia del COVID-19. Metodología. Estudio de diseño no experimental, descriptivo y analítico, con una dimensión temporal transversal. La muestra no probabilística por conveniencia estuvo conformada por 265 estudiantes de 7.° a 12.° grado (entre 11 y 18 años) de ambos sexos de la localidad de El Carmen, sur de Chile, quienes realizaron un cuestionario en línea sobre contexto, autoestima y hábitos de sueño. Análisis de resultados. La mayoría del estudiantado se percibe con autoestima media o baja (26,4% y 24,9%, respectivamente). Se encontró que estudiantes que generalmente se dormían antes de la medianoche, no se despertaban con cansancio o lo hacían ocasionalmente, no tenían pesadillas y generalmente no tenían problemas para conciliar el sueño, tenían una autoestima más alta que quienes se dormían después de la medianoche, se despertaban regularmente con agotamiento, tenían pesadillas y problemas para conciliar el sueño, respectivamente. Conclusiones. Se concluyó que un alto porcentaje de estudiantes tenía autoestima media o baja, y que el estudiantado que reportó tener una mejor higiene del sueño tenía una autoestima más alta en comparación con aquel que tenía una peor higiene del sueño. De esta forma, son necesarios más estudios que aborden esta temática, más aún en los contextos de incertidumbre, donde se presume que estas podrían incidir tanto en los hábitos de vida como en la salud mental.

Resumo Objetivo. Analisar a autoestima de estudantes chilenos de escolas públicas e determinar sua associação com variáveis de higiene do sono após o primeiro ano de restrições devido à pandemia de COVID-19. Método. Estudo de desenho não experimental, descritivo e analítico, com uma abordagem transversal temporal. A amostra não probabilística por conveniência foi composta por 265 estudantes do 7º ao 12º ano (entre 11 e 18 anos) de ambos os sexos da localidade de El Carmen, sul do Chile, que responderam a um questionário online sobre contexto, autoestima e hábitos de sono. Análise de Resultados. A maioria dos estudantes percebia ter uma autoestima média ou baixa (26,4% e 24,9%, respectivamente). Verificou-se que os estudantes que geralmente dormiam antes da meia-noite, não acordavam cansados ou o faziam ocasionalmente, não tinham pesadelos e geralmente não tinham problemas para conciliar o sono, apresentavam uma autoestima mais alta do que aqueles que dormiam após a meia-noite, acordavam regularmente cansados, tinham pesadelos e problemas para conciliar o sono, respectivamente. Conclusões. Concluiu-se que uma alta porcentagem de estudantes apresentava autoestima média ou baixa e que os estudantes que relataram ter uma melhor higiene do sono apresentavam uma autoestima mais alta em comparação com aqueles que tinham uma pior higiene do sono. Dessa forma, são necessários mais estudos que abordem esses temas, especialmente em contextos de incerteza, onde se presume que eles possam influenciar tanto os hábitos de vida quanto a saúde mental.

Abstract Objective To compare the cardiovascular risk and physical fitness, according to type of school in a national sample of Chilean school students. Methods A total of 7,218 students participated, who completed all the national tests of the National System for Measuring the Quality of Education, which included physical fitness and anthropometric tests. The results were compared according to the type of educational establishment and anthropometric indicators were considered. Physical fitness was measured by lower extremity strength, abdominal strength, upper extremity strength, trunk flexibility, exertional heart rate, and cardiorespiratory fitness. Body mass index, heart rate, and waist-to-height ratio were analyzed as predictors of cardiovascular risk. Results There were differences according to the type of establishment in the predictors of cardiovascular risk (p < 0.05). Differences were also found in the physical fitness tests evaluated (p < 0.01). Students in private schools (PSC) and subsidized schools (SC) had lower levels of cardiovascular risk and higher levels of physical fitness than public schools (PS) and schools with delegated administration (DA). Conclusions In conclusion, students in educational establishments with a higher socioeconomic level have lower levels of cardiovascular risk and better physical fitness than students in public establishments. The authors suggest considering specific school interventions to mitigate cardiovascular risk and improve physical fitness among this vulnerable population. To this end, future studies should analyze the characteristics of physical activity and nutritional habits in schools to determine the factors that affect the results. 7218 7 218 7,21 participated Education considered strength flexibility rate index waisttoheight waist height p 0.05. 005 0.05 . 0 05 0.05) 0.01. 001 0.01 01 0.01) PSC (PSC SC (SC PS (PS DA. DA (DA) conclusion population end 721 21 7,2 00 0.0 (DA 72 2 7, 0.

RESUMEN: La preparación militar depende en gran medida de la aptitud física y la capacidad operativa de su personal. Este estudio tiene como objetivo mejorar la eficacia de los protocolos de evaluación y clasificación de la composición corporal dentro del contexto militar. Se realizó una evaluación integral de 4.370 militares chilenos en servicio activo, centrándose en las características antropométricas, incluido el tejido adiposo, el tejido muscular y los índices antropométricos. El estudio observó diferencias significativas en la composición corporal entre sexos, con los hombres exhibiendo niveles más bajos de porcentaje de grasa corporal (hombres: 26,28 %; mujeres: 34,62 %) pero niveles más altos de masa muscular (hombres: 42,0 %; mujeres: 36,0 %;), índice de músculo esquelético (hombres: 11,81; mujeres: 9,31) e índice de masa magra (hombres: 19,92; mujeres: 18,45) en comparación con las mujeres. Se observaron altos niveles de tejido muscular en ambos grupos. Al integrar estos hallazgos en un protocolo de evaluación estandarizado, se logró una clasificación más precisa del personal militar, superando los métodos tradicionales utilizados en poblaciones obesas sedentarias. El estudio aboga por la adopción futura de un modelo de evaluación basado en algoritmos de inteligencia artificial (IA), que consideren la naturaleza multifacética de la composición corporal y su impacto en la capacidad operativa. Un modelo de este tipo permitiría a las fuerzas militares optimizar la aptitud física y la preparación de su personal, mejorando así su eficacia en las operaciones de despliegue.

SUMMARY: Military readiness relies heavily on the physical fitness and operational capability of its personnel. This study aims to enhance the effectiveness of body composition assessment and classification protocols within the military context. A comprehensive evaluation of 4370 active-duty Chilean military personnel was conducted, focusing on anthropometric characteristics, including adipose tissue, muscle tissue, and anthropometric indices. The study observed significant differences in body composition between genders, with men exhibiting lower levels of body fat percentage (men: 26.28 %; women: 34.62 %) but higher levels of muscle mass (men: 42.0 %; women: 36.0 %;), skeletal muscle index (men:11.81; women: 9.31), and fat-free mass index (men: 19.92; women: 18.45) compared to women. High levels of muscle tissue were observed in both groups. By integrating these findings into a standardized assessment protocol, a more accurate classification of military personnel was achieved, surpassing traditional methods used in sedentary obese populations. The study advocates the future adoption of an assessment model based on artificial intelligence (AI) algorithms, which consider the multifaceted nature of body composition and its impact on operational capability. Such a model would enable military forces to optimize their personnel's physical fitness and readiness, thus enhancing their effectiveness in deployment operations.

ABSTRACT This study examined the moderators of sex, maturity sexual stage, and age in the intervention of high intensity and moderate-intensity exercises on changes in cardiorespiratory fitness (CRF) and body composition. Forty-eight children (aged 9,48±0.5 years); 32 girls and 16 boys; were selected randomly to perform high-intensity intermittent games (HIIG) and moderate-intensity games (MIG). The intervention is applied in the physical education (PE) class. Twenty meters shuttle run test was used to estimate CRF; and body composition was measured by body fat percentage (BF%), the skinfolds sum, body mass index (BMI) z-score, and waist circumference (WC). Sex, sexual maturity stage, and age did not moderate the result on changes in Delta difference (Δ) in CRF. Furthermore, no moderation was observed in the interaction between groups of CRF intervention. A significant moderation of the interaction between groups of the intervention was observed on ΔWC. Hence, they differ in their effectiveness according to sexual maturity stage in connection to ΔWC. In sexual maturity stage and age, a quasi-significant value of moderation of the interaction between groups of intervention respect ΔBMI z-score was also observed. HIIG can be incorporated into PE classes regardless of sex, sexual maturity stage, and age ΔCRF. MIG group may have a better effect on body composition on students with sexual maturity stage Tanner 2 and 9-year-old children. High-intensity intermittent activities improve CRF and can be incorporated with no restriction of the moderators studied in PE class. Therefore, it turns into an alternative for PE class.

Resumen Introducción: Los bajos niveles de Consumo Máximo de Oxígeno (VO2max) evaluados en escolares chilenos, sugieren la puesta en marcha de entrenamientos que mejoren la capacidad aeróbica. Objetivo: Analizar el efecto de un método de Entrenamiento Intervalado de Alta Intensidad sobre el Consumo Máximo de Oxígeno en escolares chilenos. Materiales y métodos: Treinta y dos escolares de octavo año básico divididos en dos grupos fueron parte del estudio (grupo experimental = 16 y grupo control = 16). La principal variable analizada fue el Consumo Máximo de Oxígeno a través del Test de Course Navette. Se aplicó un método de Entrenamiento Intervalado de Alta Intensidad basado en la Velocidad Aeróbica Máxima obtenida a través del Test. Para el análisis estadístico se utilizó un ANOVA Mixto. Resultados: El grupo experimental presentó un aumento significativo en el Consumo Máximo de Oxígeno entre el pre test y post test al ser comparado con el grupo control (p < 0.0001). Conclusión: Los resultados del estudio mostraron un efecto positivo del Entrenamiento Intervalado de Alta Intensidad sobre el Consumo Máximo de Oxígeno. Al término del estudio, se concluye que el Entrenamiento Intervalado de Alta Intensidad es una buena metodología de estimulación para escolares chilenos.

Abstract Introduction: The low levels of maximum oxygen consumption (VO2max) evaluated in Chilean schoolchildren suggest the startup of trainings that improve the aerobic capacity. Objective: To analyze the effect of a High-intensity Interval Training method on maximum oxygen consumption in Chilean schoolchildren. Materials and methods: Thirty-two high school students from the eighth grade, who were divided into two groups, were part of the study (experimental group = 16 students and control group = 16 students). The main analyzed variable was the maximum oxygen consumption through the Course Navette Test. A High-intensity Interval training method was applied based on the maximum aerobic speed obtained through the Test. A mixed ANOVA was used for statistical analysis. Results: The experimental group showed a significant increase in the Maximum Oxygen Consumption between the pretest and posttest when compared with the control group (p < 0.0001). Conclusion: The results of the study showed a positive effect of the High-intensity Interval Training on the maximum consumption of oxygen. At the end of the study, it is concluded that High-intensity Interval Training is a good stimulation methodology for Chilean schoolchildren.