Estilos de vida poco saludables, asociados a casos de sedentarismo, obesidad y sobrepeso, constituyen un grave problema de salud de la población infantil en España. A pesar de los esfuerzos de organismos como la Organización Mundial de la Salud (OMS) por promover programas de promoción y educación para la salud en los colegios, los índices de sobrepeso y obesidad siguen siendo muy elevados en nuestro país. El objetivo de este estudio fue determinar el nivel de actividad física en escolares españoles de 5º y 6º de educación primaria. Participaron 1009 estudiantes de 10 y 12 años (Medad = 10.85, DE = 0.79), empleando como instrumento para la recogida de datos el Inventario de Actividad Física Habitual para Escolares (IAFHE). Los resultados muestran diferencias estadísticamente significativas respecto del género y la práctica deportiva fuera del colegio (NPFC) (p < .001), la práctica de actividad física durante el recreo (AFDR) (p < .001) y la práctica de actividades sedentarias (PAS) (p < .001); también, respecto de la edad y la AFDR (p = .001). Los niños practican mayor cantidad de actividad física que las niñas dentro y fuera del colegio, pero, en ambos casos, están por debajo de las recomendaciones de la OMS, debiendo reflexionar sobre los hábitos saludables fomentados desde la educación física escolar.  Abstract. Unhealthy lifestyles, associated with cases of sedentary lifestyle, obesity and overweight, constitute a serious health problem for children in Spain. Despite the efforts of organizations, such as the World Health Organization (WHO), to promote health promotion and education programs in schools, rates of overweight and obesity remain very high in our country. The objective of this study was to determine the level of physical activity in Spanish students of 5th and 6th grade of primary education. A total of 1009 students of 10 and 12 years old (Mage = 10.85, DE = 0.79), responded the Inventory of Habitual Physical Activity for Schoolchildren (IAFHE), used as the instrument for data collection. The results show statistically significant differences by gender and out-of-school sports practice (NPOS) (p < .001), physical activity during recess (PADR) (p < .001) and sedentary activities (PSA) (p < .001); by age and PADR as well (p = .001). Boys practice more physical activity than girls in and out of school, but, in both cases, they are below WHO recommendations, which should arouse a reflection on healthy habits promoted through school physical education.

The current technological revolution has benefited the development of the human being. However, sedentary lifestyle has increased, and consequently, health problems, such as childhood obesity. The combination of physical activity with appropriate educational strategies are the most effective tools to fight against childhood obesity. But it is necessary to take into account the motivation towards the practice of physical exercise to generate the necessary adherence to generate healthy lifestyles and increase the effectiveness of the programs. Therefore, the objective of this study was to determine the reasons for sports practice of students in grades 5 and 6 of Primary Education according to gender and age in 4 Galician schools. 163 students between 10 and 12 years old, of which 80 were boys (49.07%) and 83 girls (50.07%) covered the questionnaire of the Self-Report of Motives for the Practice of Physical Exercise (AMPEF) and the results obtained showed differences statistically significant in the gender factor in weight and body image (p = .022), competition (p < .001), muscular strength and endurance (p = .001) and health urgency (p = .037). Schoolchildren show a motivation for the practice of activity influenced by weight and body image, competition, muscular strength and endurance, these motivations being greater in boys, and the urgency of health in girls.