This study is a clinical trial will be carried out during academic term to assess the potential effects of the Daily Mile program on health-related physical fitness and sleep quality on overweight/obese schoolchildren.The trial will be taken place in Bucaramanga, Colombia

Introduction: Regular physical activity is essential for promoting health and well-being, especially during childhood and adolescence. The World Health Organization (WHO) recommends that children and adolescents (ages 5 to 17 years) should average 60 minutes of moderate-to-vigorous intensity physical activity per day, primarily of aerobic capacity, with the aim of preventing and/or reducing the incidence of overweight non-communicable diseases in adulthood and modifying emotional behaviors such as enjoyment, intrinsic motivation and perceived autonomy, among others. Modifications in these recommendations have probably been generated due to the increase of physical inactivity prevalence and sedentary behaviours in the population, which have been related to an increased risk of obesity, cardiovascular disease, diabetes, coronary heart disease and stroke, as well as delayed cognitive development and decreased in the academic performance of children and young people.

Recently, the WHO classified physical inactivity as the fourth mortality risk factor with 6%, after hypertension (13%), smoking (9%) and diabetes (6%)9. In Colombia, the National Survey of the Nutritional Situation (ENSIN 2015) found that only 35.8% of boys and 26% of girls between 6 and 12 years of age complied with the physical activity recommendations.

The previous Survey shows that 25.3% of boys and 23.5% of girls between 5 and 12 years of age are overweight or obese, which means an increase of 5.1%. and 6.2% respectively in relation to the year 2010 and 10.1% and 9.8% in relation to the year 2005, indicating a substantial increase in the data related to body weight In Colombia. In 2016 worldwide, it was estimated that the number of children under five years of age with obesity exceeded 41 million. In the same way, it has been found that the presence of overweight and obesity increases the probability of the development of non-communicable diseases such as diabetes, cardiovascular diseases and metabolic syndromes.

In response to this situation, one of the objectives established by the WHO's global action plan on physical activity 2018-2030 was to reduce the prevalence of physical inactivity by 10% by 2025 and 15% by 2030. For this reason, two of the strategic objectives have been called "Create active environments" and "create active people", whose purpose is to create and promote spaces and access to programs and opportunities that increase physical activity in their different communities and, that in the case of the school population, a greater participation in physical activity leads to a greater capacity for concentration and cognitive function, which could result in an improvement in academic performance.

A physical activity program to be developed in school environments is The Daily Mile (DM). It is an initiative created at St Ninian Primary School (Stirling, Scotland) in 2012 that was initially proposed as a solution to a perceived lack of physical fitness in children between 5 and 12 years of age. The DMaily Mile encompasses a 15-minute walking, jogging or running each day, without additional material resources or clothing, within their class time.

Although the Daily Mile program has grown in popularity among schools in the United Kingdom, the United States, Italy, and the Netherlands, among others, there is no evidence of research carried out on schoolchildren implementing this program in Colombia or in overweight/obese children. There is an urgent need for results from well-designed experimental studies that enable a better understanding of the impact of exercise in school environments on various health outcomes.

Methodology: The intervention will start in the middle of the first academic term. The Daily Mile intervention will be consisted of walking, jogging or running for ~ 15 min (~ one mile) of exercise at a pace self-selected by each individual child, outside the school buildings during recess time, three times a week. Children were instructed to maintain active for the full 15 min and, if necessary, to stop for resting only occasionally. The program will be guided and supervised by physical education professionals previously trained. All the sessions will take place at the outside School buildings.

Inclusion Criteria:

• Be enrolled at the school.
• Be aged between 11 and 17 years, healthy (physically, psychologically and cognitively).
• Present a BMI greater than or equal to the 85th percentile for their gender and age, according to WHO (World Health Organization).
• Be free of any medication that could interact with the protocol (e.g., cardiac abnormalities, hypertension, diabetes, orthopaedic, neuromuscular, or neurological disorders).
• Present no contraindication to physical activity

Exclusion Criteria:

- Perform any scheduled physical activity outside the curricula.