Moderate-to-vigorous physical activity (MVPA) is associated with lower rates of chronic health issues, including diabetes and obesity in children and adolescents [
1‐
3]. Despite the health benefits, previous research has shown that MVPA levels of adolescents are low in Hong Kong [
4‐
6] and in other parts of the world [
7,
8]. As physical activity and inactivity patterns during childhood and adolescence may be carried onto the latter stages in one’s lifespan [
9,
10], increasing and sustaining adolescents’ activity levels is important. Apart from general MVPA, researchers have found that vigorous activity, independent from moderate forms, may be strongly associated with young people’s health [
11]. Physical activity of vigorous intensity is difficult to accumulate during most day-to-day activities. Schools and, more specifically, physical education (PE) classes are suitable venues for promoting all forms of MVPA, which should also include vigorous forms of physical activity. This is because school PE is compulsory for school-aged students and, thus, has the potential to reach nearly all adolescents [
5,
12,
13], allowing them to explore and learn activities that will ideally allow them to remain active and fit throughout their lifespans.
To increase students’ activity levels in PE, a number of school-based interventions have been designed and implemented. In a review and meta-analysis, Lonsdale et al. [
14] categorized published school-based interventions into two broad types of strategies, namely teaching strategies and fitness infusion. Specifically, “teaching strategies” are methods used by teachers to maximize students’ MVPA by activity selection, class organization, and instructional practices (e.g., [
15,
16]). Whereas “fitness infusion” are strategies used by teachers to supplement existing lessons with additional vigorous activities (e.g., [
17,
18]). Most existing interventions have employed one of these approaches. However, as vigorous activities may lead to reduced affective responses [
19,
20], fitness infusion strategies may actually negatively impact students’ motivation, and thus future participation. In response, our goal was to create an intervention using fitness infusion that could be delivering in a manner that would have a positive impact on students’ autonomous motivation for physical activity. Essentially, teachers will be trained to teach in a way that supports students’ basic psychological needs (i.e., teaching strategies). We also designed a fitness training protocol using “fitness dice” to increase students’ active participation in fitness exercises (i.e., fitness infusion), and to increase their enjoyment while doing so. The effectiveness of the intervention will be evaluated using a cluster randomized controlled trial.
School physical education: The Hong Kong context
Physical education is a compulsory subject in Hong Kong schools. Schools are recommended to allocate 5% to 8% of total curriculum time for PE [
21]. In practice, this translates to approximately 60 to 90 min of PE time per week in secondary schools. Despite being a key learning area of the Hong Kong general curriculum [
21], and taught by teachers who received professional training in the subject, PE has been marginalized as it does not contribute to “academic achievements” [
22]. As a result, some students are disinterested in PE and physical activity in general. Although “health and fitness” is one of the six strands of the PE key learning area [
12], such aspects only take up small portions of most classes. Typically, a Hong Kong PE lesson will consist of a short warm-up period, occasionally followed by a short fitness session. Through the authors’ observation, fitness activities other than running, push-ups and sit-ups are extremely rare. Afterwards, the majority of time within the class will be spent on teaching sports skills, which focus mainly on track and field or team ball games. Students’ engagement in activities is often low, even during game play as most schools have limited playing space, therefore many students will have to sit out. In view of these issues, we designed an intervention with the aims to increase students’ involvement in fitness activities, thus their activity levels, and to make PE more fun and engaging.
The Self-determined Exercise and Learning For FITness (SELF-FIT) intervention was designed based on tenets of self-determination theory (SDT) [
15,
23‐
25]. It is a multi-component, school-based intervention aimed to enhance teachers’ need supportiveness behaviors, students’ basic need satisfaction, motivation and their physical activity behaviors. According to tenets of SDT, three human basic psychological needs of competence (feeling competent and effective), autonomy (feel being the true origin of engaging in the activity), and relatedness (feel a sense of connection with other people) are important determinants of adaptive forms of motivation, behaviors, and well-being. When these needs are satisfied, individuals are more likely to show higher levels of adaptive motivation towards the corresponding behavior, and in turn increase their engagement in such activities. Moreover, basic need satisfaction may also directly enhance one’s psychological well-being, such as less depressive symptoms or higher quality of life [
24]. Within SDT, motivation can be broadly categorized into two forms, namely autonomous and controlled motivation. Autonomous motivation represents the more adaptive form of motivation, and is represented by engaging in an activity for fun and enjoyment, or the individual feels that the outcomes of engaging in the activity would be personally important. Within the domain of school PE, this type of motivation has been found to be related to students’ MVPA during PE [
26,
27] or in their leisure time [
6,
27], and their psychological well-being [
28,
29]. Therefore, school-based interventions designed to enhance students’ basic need satisfaction and autonomous motivation may induce positive changes in activity behaviors and psychological well-being in students.
Research has shown that students’ autonomous motivation towards PE may be affected by the interpersonal style utilized by the teacher. Students’ need satisfaction and autonomous motivation are related to teachers’ need supportive behaviors [
28,
30,
31]. By definition, need supportive behaviors support individuals’ basic need satisfaction, which include provision of non-contingent positive feedback, providing choices and meaningful rationales to tasks, and taking the perspective of students and acknowledging their negative feelings [
32]. Importantly, autonomy supportive teaching styles can be trained. For example, Cheon and colleagues [
33] demonstrated that when teachers were trained to teach in autonomy supportive ways, students showed higher levels of autonomous motivation, greater engagement in class, and future intentions to exercise. Having higher levels of motivation may also have a carry-on effect to students’ leisure time physical activity [
27]. Therefore, in the current study, we will examine whether the intervention will have an effect on students’ leisure time MVPA. Apart from teacher behaviors, we will also embed game play elements to the fitness activities. Specifically, we have designed a set of four fitness dice with interchangeable faces. Each die includes changeable exercise cards for the following aspects of health-related fitness, namely flexibility, cardiovascular fitness, upper and lower body muscular fitness (detailed descriptions are presented in the method section).
A cluster randomized controlled trial will be used to evaluate the effectiveness of the SELF-FIT intervention. Through the trial, we aim to examine whether the school-based intervention could (1) increase teachers’ need supportiveness during PE (rated by students); (2) enhance students’ basic need satisfaction and autonomous motivation towards PE, (3) increase their MVPA during school PE, and (4) increase their leisure time MVPA. Specifically, Secondary 2 (equivalent to Grade 8) students and their teachers will be recruited to take part in the trial. Participating teachers will be randomly allocated to either an experimental group or a wait-list control group after baseline measures of students are taken. Teachers in the experimental group will then attend two half-day workshops, and employ the designed intervention in their classes. We hypothesize that at follow-up, students in the experimental group, compared to those in the control group, will show higher levels of MVPA during school lessons and in their leisure time, report higher levels of perceived need support, autonomous motivation, intentions to be physically active, and psychological well-being.