Accepted for/Published in: Journal of Medical Internet Research
Date Submitted: Jul 10, 2025
Open Peer Review Period: Jul 11, 2025 - Sep 5, 2025
Date Accepted: Mar 2, 2026
(closed for review but you can still tweet)
Effectiveness of a blended intervention to promote physical activity among office employees: a randomised controlled trial
ABSTRACT
Background:
Physical inactivity is a critical risk factor for non-communicable diseases (NCDs), particularly among office employees with predominantly sedentary work environments. Addressing this issue is critical to improving public health and workplace productivity.
Objective:
This study aimed to evaluate the effectiveness of a blended intervention, combining web-based intervention and interactive e-workshops, in promoting moderate-to-vigorous physical activity (MVPA) among physically inactive office employees in Hong Kong.
Methods:
A 24-week randomized controlled trial (RCT) was conducted with 141 participants allocated equally to three groups: blended intervention, web-based intervention, and control. MVPA was objectively measured using accelerometers at baseline, postintervention (12 weeks), and follow-up (24 weeks). Retention, engagement rates, and intervention acceptability were also assessed. Statistical analyses included generalized linear mixed models and paired t-tests.
Results:
At postintervention, the blended group achieved significantly higher MVPA levels compared to the control group (β = 0.252, 95% CI [0.019, 0.485], p = 0.034) and the web-based group (β = 0.290, 95% CI [0.065, 0.515], p = 0.012). These improvements were sustained at follow-up, with the blended group outperforming both the control (β = 0.376, 95% CI [0.141, 0.610], p = 0.002) and web-based groups (β = 0.364, 95% CI [0.134, 0.594], p = 0.002). Retention rate was high across all groups (83% overall), highlighting its feasibility and acceptability.
Conclusions:
The blended intervention effectively increased MVPA levels and demonstrated its potential to address physical inactivity among office employees. These findings highlight the value of integrating digital tools with interactive components for sustainable behavior change in workplace settings. Clinical Trial: The blended intervention effectively increased MVPA levels and demonstrated its potential to address physical inactivity among office employees. These findings highlight the value of integrating digital tools with interactive components for sustainable behavior change in workplace settings.
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Copyright
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