This study is realized in 2 primary schools in the city of Tarbes (France), located in a disadvantaged neighbourhood : 352 children are included in the study.

This study has many goals: 1) to propose an intervention to promote PA (Physical Activity) and reduce ST (Sedentary Time) of children aged 6 to 13 years from a primary school located in a disadvantaged neighbourhood and measures the effectiveness of this intervention (1rst grade-5th grade). This intervention was based on the factors of socio-ecological model related to health behaviours. The levels of PA and ST of the experimental school will be compared to a control school with the realization of pre and post intervention measures. 2) To study the relationships between PA, ST, motors skills, attentional abilities and academic achievement. 3)To realise a descriptive analysis of PA and ST of children in 2nd and 5th grade from France and Spain (observational study). For this goal, an other school in Spain was included in the study (city of Huesca, 60 children).

Physical activity (PA) has decreased drastically in the 21st century in developed and industrialized societies. In 2009, 23.3% of the world's population did not comply with WHO's recommendations for physical activity, reaching real levels of pandemic. Technological advances have contributed to the emergence of new leisure activities, which may preclude the participation in PA and encourage sedentary behaviours. However, it is now well known that PA has numerous benefits on physical, psychological and social health. Thus, promoting PA becomes a necessity for adults and even more for children since healthy habits that are adopted during childhood will last throughout life and predict adult health. Hence, for this last population, 60 minutes of moderate-to-vigorous physical activity (MVPA) per day are recommended in public health guidelines.

A recent project named "Capas-Cité", created in 2012 in Tarbes (France) and in Zaragoza (Spain) realize PA programs and promotion actions that have a beneficial impact on health. These two similar cities have been selected for their geographical proximity and their similarity. These programs are included in research work carried out by the University of Tarbes and the University of Zaragoza that focus on the promotion of PA. "Capas-Cité" project aims to improve the health of disadvantaged population.

The two primary schools (School A and School B) located in the disadvantaged neighbourhood of Tarbes were contacted to participate in the study. Both schools include children from grade 1 (6 years old) to grade 5 (10 years old). They have never benefited from intervention programs on the field of PA and agreed to participate in the project.

During the academic year 2016/2017, baseline assessments were carried out in the two French schools: measures of PA, ST, motors skills, attentional abilities and academic achievement. These assessments were performed in November/December 2016 (First Time - T1) and May/June 2017 (Second time - T2). The measures of attentional abilities involve only children in 2nd, 3th and 4th grade. Children in both schools had to have parental permission to participate in PA, ST and attentional abilities measurements. Motor skills were assessed for all the children at school and their academic achievement were collected.

During the academic school year 2017/2018, School A benefited of an intervention to increase PA and reduce ST. This intervention program involves all the children from grade 1 to grade 5 without parental permission. Families are not required to contribute financially participation in this project. During this intervention year, the same periods of assessment as those carried at baseline were repeated in November/December 2017 (T3) and May/June 2018 (T4). These repeated assessment time provide a first overview of the efficiency of the intervention. The school B has the intervention program during the school year 2018/2019.

Accelerometers were used to measure PA and ST. Accelerometry is a reliable and valid objective to measure PA and ST. Children should wear the accelerometer on the right side of the hip, adjusted with an elastic belt.

In Spain, only observational measures were realised. . A total of 179 children have worn accelerometers for a week. PA and ST were analysed for week end days on one hand and on the other hand according to different periods of time for weekdays: the time before school, lunch, after school and at night.54.97% of the children complied with the MVPA guidelines all days of the week. MVPA represented 67.70±17.83 min.day-1 and ST was 606.14±37.39 min.day-1 for the total sample.

Inclusion Criteria:

• Children (girls, boys) aged 5-13 years old

Exclusion Criteria:

• Physical diseases that prevent PA practice