Physical Activity and Nighttime Sleep in Adolescents.

BACKGROUND: Previous studies show contradictory results regarding the bidirectional association between physical activity and nighttime sleep. The objective of the present study was to add knowledge to these possible relationships using autoregressive models. METHOD: 214 adolescents (117 boys and 97 girls), with a mean age of 13.31 years agreed to participate. The study variables were measured with accelerometers for 7 full days over three consecutive years. The mlVAR package was used to compute estimates from multivariate vector autoregression models. RESULTS: The 5-delay models showed a better fit. Autoregressive effects were observed in sleep onset, sleep offset and sedentary behavior, which could explain the relationships found in previous studies between physical activity and sleep. Sleep onset, total sleep time, and sleep efficiency had direct effects on sedentary behavior. Moderate-to-vigorous physical activity was not related to any of the sleep variables. CONCLUSIONS: The hypothesis that there are bidirectional/reciprocal relationships between physical activity and sleep cannot be accepted.

Physical Activity and Nighttime Sleep in Adolescents / Actividad Física y Sueño Nocturno en Adolescentes

Background: Previous studies show contradictory results regarding the bidirectional association between physicalactivity and nighttime sleep. The objective of the present study was to add knowledge to these possible relationshipsusing autoregressive models. Method: 214 adolescents (117 boys and 97 girls), with a mean age of 13.31 years agreedto participate. The study variables were measured with accelerometers for 7 full days over three consecutive years. ThemlVAR package was used to compute estimates from multivariate vector autoregression models. Results: The 5-delaymodels showed a better fit. Autoregressive effects were observed in sleep onset, sleep offset and sedentary behavior,which could explain the relationships found in previous studies between physical activity and sleep. Sleep onset,total sleep time, and sleep efficiency had direct effects on sedentary behavior. Moderate-to-vigorous physical activitywas not related to any of the sleep variables. Conclusions: The hypothesis that there are bidirectional/reciprocalrelationships between physical activity and sleep cannot be accepted.(AU)

Antecedentes: Los resultados de estudios previos sobre la asociación bidireccional entre actividad física y sueñonocturno son contradictorios. El objetivo del presente estudio es intentar dar una mejor explicación a estas posiblesrelaciones utilizando modelos autorregresivos. Método: Participaron 214 jóvenes (117 varones y 97 mujeres), con unamedia de edad de 13,31 años. Las variables del estudio se midieron con acelerómetros durante 7 días completos, en tresaños consecutivos. Se utilizó el paquete mlVAR para calcular las estimaciones de modelos vectoriales de autorregresiónmultivariables. Resultados: Los modelos de 5 retrasos fueron los que mostraron un mejor ajuste. Se observaron efectosautorregresivos en el inicio del sueño nocturno, el final del sueño nocturno y los comportamientos sedentarios, quepodrían explicar las relaciones encontradas en estudios previos entre actividad física y sueño. Se observaron efectosdirectos entre el inicio, la duración y la eficiencia del sueño nocturno sobre los comportamientos sedentarios. Laactividad física moderada-vigorosa no se relacionó con ninguna variable de sueño nocturno. Conclusiones: No se puedeaceptar la hipótesis de que existen relaciones bidireccionales/recíprocas, entre la actividad física y el sueño.(AU)

[Body mass index, motives for extracurricular sport practice and family type in grade 6 Primary Education children]. / Índice de masa corporal, motivos de práctica deportiva extraescolar y modelos familiares en alumnado de 6.º de Educación Primaria.

INTRODUCTION: obesity has many edges. Therefore, three complementary studies were conducted. OBJECTIVES: study 1: determining body mass index (BMI) of the whole population of grade 6 students of a middle-size city and assessing their extracurricular sport habits. Study 2: assessing the motives for sport practice. Study 3: examining the role that family plays in extracurricular sport practice. METHODS: mixed focus, ex-post-facto transversal design. Study 1: 377 grade 6 students. INSTRUMENTS: measuring rod, scale and questionnaire. Study 2: 275 grade 6 students. INSTRUMENTS: questionnaire (BREQ-3; MPAM-R). Study 3: 228 parents. INSTRUMENT: Families' Perception Questionnaire. RESULTS: study 1: BMI: 20.73 ± 4.12 kg/m2, 38.7% overweight, 10.1% obesity, 73% practice sport. BMI: no significant differences between those who practice sports and those who do not; significant differences based on socioeconomic status. Study 2: high intrinsic motivation; motive to participate: enjoyment. Study 3: parents value the importance of doing physical activity; significant differences favor those whose children play sports and have medium-high socioeconomic status. Parents whose children play sport: good for their health/development, he/she likes/choses it, socialization and values; parents whose children do not play sport: children's lack of time, he/she does not like it (can't find a sport he/she likes), parent's lack of time. CONCLUSIONS: BMI close to overweight; extracurricular sports do not make a difference in BMI, socioeconomic status does (study 1). Sport participants intrinsically motivated, playing sports for enjoyment (study 2). Family: a model for sport practice (study 3).

Índice de masa corporal, motivos de práctica deportiva extraescolar y modelos familiares en alumnado de 6º de educación primaria / Body mass index, motives for extracurricular sport practice and family type in grade 6 Primary Education children

Introducción: la obesidad infantil tiene muchas aristas, por eso se desarrollaron tres estudios complementarios. Objetivos: el objetivo del estudio 1 fue determinar el índice de masa corporal (IMC) de toda la población de estudiantes de 6.º de Primaria de una ciudad española de tamaño medio y conocer sus hábitos de práctica deportiva extraescolar, el del estudio 2 fue conocer los motivos de práctica de los que realizan deporte extraescolar y el del estudio 3, conocer el papel que juega la familia sobre la práctica deportiva extraescolar. Métodos: enfoque mixto, diseño ex-post-facto transversal. Estudio 1: 377 estudiantes de 6.º de Primaria. Instrumentos: tallímetro, báscula, cuestionario ad hoc. Estudio 2: 275 estudiantes de 6.º de Primaria. Instrumentos: cuestionarios (BREQ-3; MPAM-R). Estudio 3: 228 progenitores. Instrumento: Cuestionario de Percepción de las Familias. Resultados: estudio 1: IMC: 20,73 ± 4,12 kg/m2, 38,7% sobrepeso, 10,1% obesidad, 73% hace deporte; IMC: no existen diferencias significativas entre practicantes y no-practicantes, sí en base al nivel socioeconómico. Estudio 2: alta motivación intrínseca; motivo de participación: diversión. Estudio 3: los progenitores valoran la importancia de hacer actividad física; diferencias significativas a favor de los que tienen hijos haciendo deporte y nivel socioeconómico medio-alto. Padres cuyos hijos hacen deporte: bueno para su salud/desarrollo, le gusta/lo eligió, socializarse y valores; padres cuyos hijos no hacen: falta de tiempo de los hijos, no le gusta/no encuentra un deporte que le guste y falta de tiempo de los padres. Conclusiones: IMC cercano al sobrepeso; la práctica de deporte extraescolar no marca diferencias en el IMC, el nivel socieconómico sí (estudio 1). Practicantes motivados intrínsecamente, lo hacen por diversión (estudio 2). La familia como modelo para hacer deporte (estudio 3)

Introduction: obesity has many edges. Therefore, three complementary studies were conducted. Objectives: study 1: determining body mass index (BMI) of the whole population of grade 6 students of a middle-size city and assessing their extracurricular sport habits. Study 2: assessing the motives for sport practice. Study 3: examining the role that family plays in extracurricular sport practice. Methods: mixed focus, ex-post-facto transversal design. Study 1: 377 grade 6 students. Instruments: measuring rod, scale and questionnaire. Study 2: 275 grade 6 students. Instruments: Cuestionnaire (BREQ-3; MPAM-R). Study 3: 228 parents. Instrument: Families' Perception Questionnaire. Results: study 1: BMI: 20.73 ± 4.12 kg/m2, 38.7% overweight, 10.1% obesity, 73% practice sport. BMI: no significant differences between those who practice sports and those who do not; significant differences based on socioeconomic status. Study 2: high intrinsic motivation; motive to participate: enjoyment. Study 3: parents value the importance of doing physical activity; significant differences favor those whose children play sports and have medium-high socioeconomic status. Parents whose children play sport: good for their ealth/development, he/she likes/ choses it, socialization and values; parents whose children do not play sport: children's lack of time, he/she does not like it (can't find a sport he/she likes), parent's lack of time. Conclusions: BMI close to overweight; extracurricular sports do not make a difference in BMI, socioeconomic status does (study 1). Sport participants intrinsically motivated, playing sports for enjoyment (study 2). Family: a model for sport practice (study 3)