Intervention to Reduce Sedentary Behavior During School Recess Among Adolescents

South China Normal University

Status: Active, not recruiting

Conditions: Sedentary Behaviour; Adolescents; Physical Activity; School-based Intervention

Treatments: Behavioral: Sedentary Interruption Intervention

Study type: Interventional

Funder types: Other

Identifiers

NCT07451535

SCNU-SPT-2025-041

Details and patient eligibility

About

This cluster randomized controlled trial evaluated the effectiveness of an 8-week, school-based behavioural intervention grounded in the Multi-Process Action Control (M-PAC) framework in promoting interruption of sedentary behaviour during school breaks among adolescents. Twelve primary and secondary schools in China, were recruited and randomly allocated (at the school level) to either an intervention group or a control group to minimise contamination and support pragmatic delivery within the school setting. Schools assigned to the intervention group implemented a multi-component programme comprising educational materials, teacher-delivered guidance, peer reminders, and health lectures, whereas control schools continued their usual routines without receiving intervention materials. The primary outcome was interruption of sedentary behaviour during school breaks assessed using self-reported measures. Secondary outcomes included physical activity levels, emotional and behavioural problems, executive function, and psychological factors related to behaviour regulation, such as motivation, planning, and habit. Findings from this trial are intended to inform the development and implementation of feasible, theory-informed school strategies to reduce sedentary behaviour during school breaks.

Full description

This study was a cluster randomized controlled trial designed to evaluate the effectiveness of a school-based intervention grounded in the Multi-Process Action Control (M-PAC) framework to promote interruption of sedentary behaviour during school breaks among adolescents. A cluster randomization design was adopted, with schools as the unit of randomization, to minimise contamination between participants and to enhance the feasibility of intervention delivery within the school setting.

Twelve primary and secondary schools in China were recruited using convenience sampling and randomly allocated to either an intervention group or a control group. Schools were recruited through existing school partnerships and administrative feasibility considerations. The majority of participating schools were located in Guangdong Province (n=9), reflecting the location of the coordinating research team and the primary recruitment network. To enhance the diversity of school contexts and improve the external validity of findings, additional schools were recruited from Hainan (n=1) and Shanxi (n=2) using the same eligibility criteria and standardized implementation procedures across sites. The intervention was implemented over an 8-week period. Schools assigned to the intervention group received a multi-component programme informed by the M-PAC framework, designed to target key behaviour regulation processes relevant to sedentary behaviour interruption, including reflective, regulatory, and reflexive mechanisms. Intervention components included weekly educational leaflets, guidance delivered by physical education teachers, peer reminders during school breaks, and health lectures. Schools assigned to the control group continued their usual school routines and did not receive intervention materials during the study period.

The primary outcome was interruption of sedentary behaviour during school breaks, assessed using self-reported measures. Secondary outcomes encompassed physical activity levels, emotional and behavioural problems, executive function, and social-cognitive variables derived from the M-PAC framework (e.g., attitudes, intention, and habit). In addition, process evaluation indicators (e.g., intervention fidelity) and relevant covariates (e.g., demographic characteristics, academic stress, and the school physical activity environment) were assessed to support interpretation of intervention effects.The study involved a non-clinical population and did not include biomedical or medical health outcomes. The study protocol was approved by the institutional ethics committee, and written informed consent was obtained from all participants prior to participation.

Enrollment: 1,000 estimated patients

Sex: All

Ages: 10 to 17 years old

Volunteers: Accepts Healthy Volunteers

Inclusion and exclusion criteria

Inclusion Criteria

1. Students aged 10-17 years
2. Enrolled in participating primary or secondary schools
3. Able to participate in regular school physical activities and daily routines
4. Able to understand and complete study questionnaires
5. Willing to comply with study procedures
6. Written informed consent obtained from parents or legal guardians

Exclusion Criteria

1. Diagnosed medical conditions that contraindicate participation in physical activity
2. Physical disabilities, injuries, or health conditions that limit normal participation in school-based activities
3. Participation in other structured physical activity or sedentary behavior intervention programs during the study period
4. Cognitive or language difficulties that preclude understanding of study procedures or completion of questionnaires
5. Inability or unwillingness to comply with study procedures

Trial design

Primary purpose: Other

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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1,000 participants in 2 patient groups

Usual Pratice Control

No Intervention group

Description:

Schools allocated to the control group continued their usual school routines during the 8-week study period and did not receive any intervention materials or behaviour-change components related to sedentary behaviour interruption. No additional guidance, reminders, or educational materials were provided. Data collection procedures were conducted in the same manner as in the intervention group.

Sedentary Interruption Intervention

Experimental group

Description:

The intervention was grounded in the Multi-Process Action Control (M-PAC) framework and targeted behaviour regulation processes relevant to sedentary interruption. Intervention components included: 1) Weekly educational leaflets providing information on the health risks of prolonged sedentary behaviour and practical strategies to interrupt sitting during school breaks. 2) Guidance delivered by physical education teachers, reinforcing key messages and encouraging active break behaviours. 3) Peer reminders were delivered during school breaks by class-appointed student PE representatives-one student per class nominated by the PE teacher (typically a high-performing student in PE) to support the organization and promotion of physical activity. 4) Health lectures delivered by members of the research team to enhance awareness and motivation related to sedentary behaviour interruption.

Treatment:

Behavioral: Sedentary Interruption Intervention