Intervention to Improve 24-Hour Movement Behaviors in University Students

Effectiveness of a Personalized Online Intervention for Optimizing Time Allocation Across 24-hour Movement Behaviours in College Students: a Randomized Controlled Trial

This study examined whether a personalized, WeChat-based behavioural intervention could help improve how university students allocate their time across daily movement behaviours, including physical activity, sedentary behaviour, and sleep.

University students were randomly assigned to either an intervention group or a control group. Participants in the intervention group received individualized guidance, feedback, and behaviour-change support delivered through WeChat. The intervention was designed to help participants develop more balanced daily movement behaviour patterns within a 24-hour day. Participants in the control group continued their usual routines without receiving intervention materials.

The primary outcome of the study was the time-use composition of 24-hour movement behaviours, reflecting how daily time was distributed across physical activity, sedentary behaviour, and sleep. Psychological factors related to behaviour regulation, such as motivation, planning, and habit, were also assessed.

The results of this study aim to inform the development of theory-informed, personalized digital interventions that support healthier daily movement behaviour patterns among university students.

This randomized controlled behavioural study was conducted to evaluate the effectiveness of a personalized, online intervention based on the Multi-Process Action Control (M-PAC) framework in optimizing the time-use composition of 24-hour movement behaviours among university students.

Participants were randomly assigned to either an intervention group or a control group. The intervention group received a personalized behavioural program delivered via WeChat. The program was designed to support more optimal allocation of daily time across physical activity, sedentary behaviour, and sleep by targeting key behavioural processes, including reflective, regulatory, and reflexive mechanisms. Intervention content included individualized feedback and behaviour-change support tailored to each participant's movement behaviour profile. The control group did not receive intervention materials and continued their usual daily routines.

The primary outcome was the time-use composition of 24-hour movement behaviours, defined as the relative distribution of time allocated to physical activity, sedentary behaviour, and sleep within a finite 24-hour period. Secondary outcomes comprised psychological constructs related to behaviour regulation, derived from the Multi-Process Action Control (M-PAC) framework. These constructs included affective attitude, instrumental attitude, perceived capability, perceived opportunity, intention, planning, self-monitoring, identity, and habit, and were assessed using validated Chinese-language self-report questionnaires with established psychometric properties. In the present study, healthy time allocation of 24-hour movement behaviours was operationally defined in accordance with the Canadian 24-Hour Movement Guidelines for Adults, which recommend regular engagement in moderate-to-vigorous physical activity, participation in light-intensity physical activity across the day, limited recreational screen time, adequate sleep duration, and regular muscle-strengthening activities.

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.

Inclusion Criteria

1. aged 18-25 years;
2. no severe physical or psychological conditions, no contraindications to exercise, and no major surgery in the past six months;
3. willingness to wear an accelerometer and participate in the online intervention;
4. failure to meet at least one recommendation of the Canadian 24-Hour Movement Guidelines for Adults (18-64 years) for PA, sedentary behaviour, or sleep -

Exclusion Criteria:

1. Presence of severe physical or psychological conditions that could limit safe participation in physical activity.

2. Medical contraindications to exercise or a history of major surgery within the past six months.

3. Inability or unwillingness to wear an accelerometer or to engage in the online intervention.

4. Meeting all recommendations of the Canadian 24-Hour Movement Guidelines for Adults (18-64 years) at baseline.

   -