Background
Opportunities for children and youth to be physically active have declined in many countries in recent decades due to environmental factors, parental rules, and school policies [
1]. Since the strong link between health and education was recognized worldwide [
2,
3], public health professionals as well as researchers have identified schools as a strategic place to promote physical activity (PA) [
3‐
6]. In the last decade, schools in the USA and in some European countries have reduced the time devoted to Physical Education (PE) in the school curriculum (in Spain, for example, primary and secondary schools devote 2 h/week to PE) [
7]. Results from eight European countries showed that a low percentage of children met the minimum recommended of 60 min of moderate-to vigorous physical activity per day (MVPA) (30.4% in Spain) [
8]. Since PA behaviors are developed early in life and may persist throughout childhood and adolescence [
9,
10], adequate PA level in childhood may also be essential for the prevention of obesity and chronic diseases in later life [
11]. In children, regular PA is associated with reduced rates of obesity [
12], improved academic and cognitive achievement [
13], better sleep health [
14], and improved health-related quality of life [
15‐
17]
. A reasonable way to assist school-age children to increase their PA levels is to help them take every opportunity to be active throughout the day [
18]. Active commuting to school [
19], PE lessons, and active school recess [
20] could provide children with opportunities to engage in PA during school days.
Children who actively commute to/from school had 24 additional minutes of MVPA per day compared to those who did not [
21]. Previous intervention studies in primary school children reported inconsistent results, such as increased rates of cycling and walking to school [
22], increased rates of cycling to school only [
23], and no effect on rates of cycling to school [
24]. Thus, further studies need to examine the effect of an intervention program based on active commuting to/from school. Initiatives such as Safe Routes to School [
25,
26], the Walking School Bus [
27], the Walk to School program [
28], and the School Travel Plan program [
29] have been implemented to increase children’s walking and bicycling to/from school with successful results in some cases. However, a systematic review by Chillón et al. [
30] concluded that more research with higher quality study designs and measures was needed to identify the most successful strategies for increasing the frequency of active commuting to/from school.
PE lessons are an ideal setting to improve children’s fundamental movement skills, increase PA and physical fitness, and improve health [
7,
31,
32]. To achieve these benefits children should be involved in MVPA during at least 50% of the PE lesson time [
33]. The majority of previous interventions designed to increase children’s MVPA in PE fall into one of the two following categories: a) interventions that use teaching strategies (e.g. CATCH, SPARK, M-SPAN, Move it Grove it) [
31,
34‐
36], and b) interventions that focus on fitness [
33]. The interventions based on teaching strategies showed an increase in MVPA during PE lessons. On the other hand, studies addressing fitness focused on increasing the time of PE lessons [
37], which is not possible without a change in the Spanish official curriculum. For example, results from the CATCH intervention increased MVPA during PE lessons by 12% to meet the current recommendation for children’s PA during PE lessons [
38]. Other intervention programs found an increase in PA levels during the school day when introducing active breaks in the ordinary lessons [
39]. In general, school-based PA interventions focusing mainly on changes in PE lessons could increase PA by 5 to 45 min/dayin children and adolescents [
10]. The Government of Spain is currently promoting the participation of key stakeholders (e.g. parents, teachers, and other child educators) to help increase PA levels in children and adolescents [
40]. The Spanish Ministry of Health, Social Services, and Equality and the Ministry of Education, Culture, and Sport have developed the so-called “Active Didactic Units” [
41] aiming at increasing MVPA during PE lessons. This intervention includes two sets of eight active PE lessons specifically developed for third grade primary school children. It is freely available to all primary schools in Spain.
School recesses provide opportunities to practice motor skills [
1], and might contribute to up to 40% of children’s recommended daily PA [
42,
43]. School playgrounds are effective settings for implementing school-based interventions to increase PA during school recess [
10,
44]. However, there are different ways to increase PA during recess. The use of pedometers to report the number of steps in recess may be effective to increase PA in children [
45]. Other ways to increase PA during recess include modifying the schoolyard, using activity cards, using cones to mark activity zones, or increasing the amount of the available playground equipment [
46].
MVPA also correlates with sleep duration in children [
14,
47] and adolescents [
48]. To achieve the recommended9 to 12 h of sleep within a 24 h period [
49], it is reasonable to start modifying factors that disturb sleep, including limiting sedentary time [
50]. Of particular interest is the relationship established between sleep duration at night and PA/sedentary time during the following day, as their combined effect might increase cardio-metabolic risk markers in childhood [
11]. However, there was no increase in sleep duration in a children PA intervention conducted over 1 year [
51]. It still remains to be examined if school-based PA interventions could improve sleep duration in primary school children when sleep is objectively measured.
Different interventions including the promotion of active commuting to/from school, PE lessons, school recess interventions, and sleep behavior interventions can be performed in school-based settings. However, no previous study compared the effectiveness of those interventions on increasing PA levels in school-age children. The interventions included in the PREVIENE Project have been designed following the conceptual framework for a comprehensive school-based PA intervention [
52]. Thus, the PREVIENE Project aims to examine the effectiveness of five 8-weekschool-based interventions (active commuting to/from school, active PE lessons, active school recess, sleep health promotion, and an integrated intervention with all four components) and compare them with the control group. The final aim of the PREVIENE Project is to improve PA, fitness, anthropometry, sleep health, academic achievement, and health-related quality of life in primary school children.
Discussion
The PREVIENE Project aims to determine the effectiveness of four school-based interventions (active commuting to/from school, active PE lessons, active school recess, sleep health promotion) implemented separately as well as simultaneously in primary school children. Outcome variables will include PA, fitness, anthropometry, sleep health, academic achievement, and health-related quality of life.
Although some interventions to promote PA in primary schools have been previously evaluated [
1,
22‐
24,
70], no previous study has examined the simultaneous implementation of the multiple interventions included in the current study. Limited evidence suggests the effectiveness of multicomponent interventions to increase children overall daily PA through active commuting, PE lessons, and leisure time out school in The Netherlands [
71,
72] and through recess time, PE lessons, in-class activities, and theme activities in Denmark [
73]. In addition, only seven studies have examined the effects of school-based interventions to increase PA levels in children in Spain. None of such interventions had multiple components, and six of them focused on developing healthy lifestyle habits and one focused on PE lessons [
74]. These interventions were effective to increase PA and the number of PE lessons during school time [
75‐
77]. Therefore, the PREVIENE Project will advance the knowledge regarding the implementation and effectiveness of each of the five school-based interventions examined in this study. The results of this study will inform the design of future school-based interventions for increasing PA in children.
The present study has several strengths. The study interventions have been designed to minimize work imposed on teachers. They will focus on modifying current instructional strategies and using the existing resources. Therefore, the proposed interventions will be easy to implement at low cost. The teachers’ participation in the design and implementation of each of the interventions will allow them to gain the knowledge and skills required to train other teachers interested in using the methodology proposed by the PREVIENE Project. This will offer the participating teachers the opportunity to provide input on the design of study interventions to make them more feasible for implementation in school settings, and will facilitate development of the network of physical activity promoting schools in the city of Granada [
78].
This study has several limitations, including a relatively small sample size and that teachers will implement all the intervention. The Research team will guide and control the correct application of each intervention program.