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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Prospectively registered

Titles & IDs
Public title
Increasing Hong Kong Chinese students’ physical activity through fitness infusion and creating an autonomy supportive learning environment: Evaluation of the SELF-FIT program using a clustered randomized controlled trial
Scientific title
Increasing Hong Kong Chinese students’ moderate-to-vigorous physical activity through fitness infusion and creating an autonomy supportive learning environment: Evaluation of the SELF-FIT program using a clustered randomized controlled trial
Secondary ID [1] 286718 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
physical inactivity 295081 0
health-related fitness 295082 0
Condition category
Condition code
Public Health 295331 295331 0 0
Health promotion/education

Study type
Description of intervention(s) / exposure
The proposed intervention is named “SELF-FIT”, and is designed to promote Self-initiated, Enjoyable, Lifelong Fitness. The intervention will last for 16 weeks. The intervention has three main components, namely the “fitness dice” activity, teachers’ need support, and other motivational components. These components were designed based on tenets of self-determination theory. Specifically, each component was designed to support students’ basic psychological needs of competence, autonomy, and relatedness.

Regarding the “fitness dice” activity component, students will be given a modified 20-minute fitness activity during each of their weekly PE lessons, for a minimum of 8 consecutive lessons. The goal is to strength students’ training in four aspects of health-related fitness components highlighted by the Hong Kong Education Bureau PE curriculum - flexibility, cardiovascular fitness, muscular strength, and muscular endurance. The activity will take the form of circuit training, with four stations. At each station, students will complete 3 to 4 bouts of 30- to 60-second exercise, with rest in between. The exercise they do will be decided by the throw of a “fitness die”. The 6 sides of the dice will be easily customizable – all sides of the dice will be transparent plastic film, contents can be decided by sliding in a card/paper with the exercise description. There will be one die per station, and they will include exercises related to 1) flexibility, 2) cardiovascular endurance; 3) upper body muscle strength and endurance; and 4) lower body muscle strength and endurance. All students in the same station will do the same activity as shown on the thrown dice. Furthermore, upbeat music will be played during the 20-minute activity sessions.

The second main component of the SELF-FIT program is providing increased teacher need support. Essentially, teachers will be trained to teach in manners in which students’ basic psychological needs are supported. For example, teachers are encouraged to allow students to choose their stations and select an appropriate intensity for each activity; provide positive, information feedback; and taking students’ perspectives and acknowledging negative feelings. According to SDT, when students’ needs are satisfied, they will more likely engage in these activities during their leisure time as well.

Finally, the SELF-FIT program also includes other motivational strategies, such as goal-setting, self-monitoring, and role modeling. Specifically, all participating students will be given a PE report/record card. Based on students’ result in the previous assessment, students will note down on the card which fitness components s/he will have to improve. Students will be encouraged to set goals s/he would like to achieve during the school academic year (with respect to physical fitness). They will be asked to set both short- and long-term goals. A small calendar will be printed on the card for students to tick what type of exercises (flexibility, cardio, or muscular training) they completed on each day. Finally, teachers will be asked to encourage, but not pressure (so the cards will not be collected), students to complete the record cards. Teachers are also encouraged to complete the record themselves and share their progress with students.

In order to train teachers how to implement the SELF-FIT intervention, teachers in the experimental group will be invited to partake in a four-hour workshop on one day. The workshops will consist of four sections. First, the principle investigator (AH) will introduce teachers to the main concepts and ideas of the intervention, and explain to them why and how the intervention can promote leisure time PA. Second, skills training will be provided to teachers in the workshop to teach them 1) the use of the fitness dice; 2) how to set varying intensities and provide choices for students to meet individual differences; and 3) special precautions to take to protect health and safety. This section will be co-led by a fitness instructor and an in-service PE teacher who had helped develop the activity.

The third section of the workshop will focus on training teachers to create an autonomy supportive classroom environment. This section will be led by the PI, and will follow an approach similar to that reported in Cheon et al. (2012). Specifically, teachers will be presented with the theoretical background and explanation of SDT. They will be provided with examples of suggested good and bad practices that are considered to be supportive of basic needs or controlling, respectively. Further, teachers will be given different scenarios, and they would need to practice how to instruct in an autonomy support manner in each of these situations. Within the one-day workshop, teachers will spend around one hours on the second (skill training) and third sections (autonomy supportive teaching methods). Finally, the PI will introduce the fitness record cards to teachers, and explain how the cards should be used.

To ensure the that the intervention was implemented as designed at the school by the teachers, research assistants will be present at two or more lessons at each participating class to video-record the class.
Intervention code [1] 291875 0
Intervention code [2] 291876 0
Comparator / control treatment
PE classes run by the school teacher, without the addition of any intervention components.
Control group

Primary outcome [1] 295078 0
Percentage of time spent in moderate-to-vigorous physical activity over 7 days, measured using accelerometers
Timepoint [1] 295078 0
Pre-intervention (4 months) and post-intervention (4 months); 2 measures (1 week duration), start of each separated by at least 1 month
Primary outcome [2] 295079 0
Percentage of time spent in moderate-to-vigorous physical activity during PE lessons, measured using accelerometers
Timepoint [2] 295079 0
Pre-intervention (4 months) and post-intervention (4 months); 2 measures (during one lesson), each separated by at least 1 month
Secondary outcome [1] 314719 0
Basic psychological need satisfaction of competence, autonomy, and relatedness. These will be measured using the Basic Needs Satisfaction in Sport Scale (Ng, Lonsdale, & Hodge, 2011).
Timepoint [1] 314719 0
Pre-intervention (4 months) and post-intervention (4 months); measure to be taken during one school day within these periods
Secondary outcome [2] 314720 0
Perceived autonomy support by teachers, measured using the Learning Climate Questionnaire (Williams
et al., 1994)
Timepoint [2] 314720 0
Pre-intervention (4 months) and post-intervention (4 months); measure to be taken during one school day within these periods
Secondary outcome [3] 314721 0
Autonomous and controlled motivation to physical activity, measured using the Chinese version of the Perceived Locus of
Causality Questionnaire (Lonsdale, Sabiston, Taylor, & Ntoumanis, 2011).
Timepoint [3] 314721 0
Pre-intervention (4 months) and post-intervention (4 months); measure to be taken during one school day within these periods
Secondary outcome [4] 314722 0
Students’ short- and long-term intention to engage in physical activity; be measured using two items (“Do you intend to exercise
regularly (at least three times a week) during your leisure time in the coming week/three months?”).
Timepoint [4] 314722 0
Pre-intervention (4 months) and post-intervention (4 months); measure to be taken during one school day within these periods
Secondary outcome [5] 314723 0
Psychological well-being, measured using the Flourishing Scale by Diener et al. (2010).
Timepoint [5] 314723 0
Pre-intervention (4 months) and post-intervention (4 months); measure to be taken during one school day within these periods

Key inclusion criteria
Secondary 2 (equivalent of grade 8) students attending Hong Kong schools.
Minimum age
12 Years
Maximum age
17 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Students diagnosed with medical situations that are deemed unsuitable to take part in moderate or vigorous physical activity

Study design
Purpose of the study
Educational / counselling / training
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Randomization of schools will be conducted after pre-intervention scores for all schools have been collected. A stratified randomization procedure, based on students 7-day MVPA, will be used to allocate schools into experimental and control groups to ensure the allocated groups have comparable pre-intervention scores.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
After stratification, each school will be assigned a random number (.001 to .999) generated using the "rand()" MS Excel function. Schools will be ranked according to their assigned number. Schools ranked in the top half will be allocated to the intervention group, while the other schools will be allocated in the control group. The names of the schools will be coded, and the randomization procedures will be conducted by a researcher blinded the codes for the schools.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

The people assessing the outcomes
Intervention assignment
Other design features
Not Applicable
Type of endpoint/s
Statistical methods / analysis
Sample size determination
A power calculation was used to estimate the required sample size based on the primary outcome of leisure time PA. Based on Kriemler et al.’s (2011) review on school-based interventions, the effect size on total MVPA is 0.44, with intra-class correlation (ICC) at .08. With an alpha level of .05 and power of .80, and using a more prudent effect size of 0.40, the required sample size is 200. In order to account for the cluster effects, this sample size is then multiplied by a design effect of 1+(m-1)*ICC, where m is the size of each cluster. In a previous study, Ha, Sum, Ng, et al. (2013) found that about 70% of students wore the accelerometers long enough to be considered as valid. Therefore, assuming an average class size of 25, we expected that data from 25*0.7 = 17 students can be recorded for each school, therefore m = 17. Hence the total required sample size for analysis is 456 (after excluding invalid cases), meaning at least 27 schools will need to be recruited. To ensure we have equal number of schools allocated in the experimental and control groups, a minimum of 28 schools will be recruited. Therefore, the total number of participants to be recruited (including potential invalid cases) will be 28*25 = 700.

Invitations will be sent to no less than 30 schools, which will be randomly drawn from the list of schools in Hong Kong. The PI will contact school principals of these schools to invite them to participate in the project. Agreement to take part in the project will be sought from principals and PE panel heads of these schools. The recruitment will end when at least 28 schools have agreed to take part in the study. An extra school on top of the required 27 required will be recruited to ensure we will have the equal number of schools in both the experimental and control groups.

Data analysis
To account for the clustering of data, multilevel analyses will be used. Specifically, a three-level model will be evaluated, with the time point at level 1, the student at level 2,and the class/school at level 3. For all outcomes (primary and secondary), the effectiveness of the intervention will be examined through the multilevel regression equation:
Outcome = Gender*B1 + Age*B2 + Group*B3 + Time*B4 + Group*Time*B5

Specifically, the intervention will be considered to be effectiveness in promoting the outcomes if the coefficient of B5 is positive and significant at p < .05 (we hypothesize that academic achievement will not deteriorate over time, and hence the coefficient for that equation should not be significant).

A causal model based on the tenets of SDT will also be tested using structural equation modeling. Specifically, we hypothesize that the intervention will lead to higher perceived autonomy support from teachers, which in turn predicts needs satisfaction, and in turn autonomous motivation. Autonomous motivation would in turn predict 7-day MVPA, self-reported intentions to engage in PA, and psychological wellbeing.

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment outside Australia
Country [1] 6881 0
Hong Kong
State/province [1] 6881 0

Funding & Sponsors
Funding source category [1] 291281 0
Government body
Name [1] 291281 0
Research Grants Committee - General Research Fund
Country [1] 291281 0
Hong Kong
Primary sponsor type
Amy S Ha
Department of Sports Science and Physical Education
Kwok Sports Building
The Chinese University of Hong Kong
Shatin, Hong Kong
Hong Kong
Secondary sponsor category [1] 289956 0
Name [1] 289956 0
Address [1] 289956 0
Country [1] 289956 0
Other collaborator category [1] 278467 0
Name [1] 278467 0
Chris Lonsdale
Address [1] 278467 0
Institute for Positive Psychology and Education
25A Barker Road, Strathfield NSW 2135
Australian Catholic University
Country [1] 278467 0
Other collaborator category [2] 278468 0
Name [2] 278468 0
David Lubans
Address [2] 278468 0
ATC Rm301C
Health and Physical Education Building
University Drive
Callaghan NSW 2308
Country [2] 278468 0

Ethics approval
Ethics application status
Ethics committee name [1] 292847 0
Joint Chinese University of Hong Kong-New Territories East Cluster Clinical Research Ethics Committee
Ethics committee address [1] 292847 0
8/F, Lui Che Woo Clinical Sciences Building, Prince of Wales Hospital, Shatin
Ethics committee country [1] 292847 0
Hong Kong
Date submitted for ethics approval [1] 292847 0
Approval date [1] 292847 0
Ethics approval number [1] 292847 0

Brief summary
The aim of the proposed project is to develop and evaluate a state-of-the-art school-based intervention, designed specifically for the Hong Kong context, to increase students’ physical activity (PA) levels in and out of school. In-service physical education (PE) teachers will be trained to implement the interventions during PE classes at their schools.

In line with global PE development trends, the Hong Kong Education Bureau initiated a series of PE curriculum reforms to indicate the importance of promoting fitness for schoolchildren aged 6 to 18 (Curriculum Development Council, 2002; Education Bureau, 2013). Schools are important institutions for promoting PA and fitness in young people (Centers for Disease Control & Prevention, 2011) and the initiatives suggest that PE curricula should focus on students’ individual differences and learning interests. However, Hong Kong students often find traditional fitness activities tedious and boring (Ha, Sum, Chan, & Ng, 2013). Therefore, a student-centered approach, focusing on moderate-to-vigorous physical activity (MVPA) should be planned and incorporated in school PE.

According to self-determination theory (SDT; Ryan & Deci, 2002), students are more likely to engage, and persist, in activities that 1) are fun and enjoyable, and/or 2) provide outcomes that are valued by the individual. Therefore, the intervention proposed in this study aims to introduce atypical activities, such as rope skipping, which students consider to be fun (Ha et al., 2013), that are suitable for the unique environments of Hong Kong, and are of moderate-to-high intensity. Based on SDT, teachers will be trained to create classroom environments which support students’ psychological needs, thereby supporting more PA engagement through lifestyle changes.

In-service teachers will be trained to implement the interventions at their schools. Teachers will be invited to attend workshops to learn how to teach the activities. Using a protocol adapted from Cheon, Reeve, and Moon (2012), teachers will also be trained to teach in more supportive ways (e.g., providing choice and meaningful rationales for the activities). The intervention will be evaluated based on students’ objectively measured physical activity levels during PE classes and in their leisure time. As PA levels in childhood and adolescence are related to that in adulthood, the intervention may support and maintain physically active lifestyles of students throughout their lifespans. This could have important implication for public health, such as reducing health-related issues including obesity and diabetes.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 57298 0
Prof Amy Ha
Address 57298 0
Department of Sports Science and Physical Education
Kwok Sports Building
The Chinese University of Hong Kong
Country 57298 0
Hong Kong
Phone 57298 0
+852 39436083
Fax 57298 0
Email 57298 0
Contact person for public queries
Name 57299 0
Johan Ng
Address 57299 0
Department of Sports Science and Physical Education
Kwok Sports Building
The Chinese University of Hong Kong
Country 57299 0
Hong Kong
Phone 57299 0
+852 39436098
Fax 57299 0
Email 57299 0
Contact person for scientific queries
Name 57300 0
Johan Ng
Address 57300 0
Department of Sports Science and Physical Education
Kwok Sports Building
The Chinese University of Hong Kong
Country 57300 0
Hong Kong
Phone 57300 0
+852 39436098
Fax 57300 0
Email 57300 0

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No Supporting Document Provided

Results publications and other study-related documents

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