Smartphone Parent-child Partner Exercises Application Study

All the recruited parent-child pairs will be randomized after baseline assessment by an independent statistician using computer randomization tool to either the FAMILY MOVE app intervention group or the HK FitNuts app control group with a 1:1 allocation ratio. Although both groups receive a stand-alone app, the apps have distinct design features: use of competition and point elements (FAMILY MOVE app) or use of traditional demonstration elements (HK FitNuts app). After both groups have completed the 8-week intervention study and follow up measurements at 1 month, 6 months and 12 months after intervention, the control group will receive the same FAMILY MOVE app. Outcome assessments will be conducted by a trained interviewer blinded to the subject group allocation.

"The parent-child pairs in the control group will be given a link to download the HK FitNuts app which was developed by Hong Kong Association of Sports Medicine and Sports Science, Department of Orthopaedics \& Traumatology of the Chinese University of Hong Kong and Hong Kong Dietitians Association to promote healthy lifestyle in Hong Kong. The app includes short video clips demonstrating basic individual exercise moves and provides other textual information related to PA. However, it does not have push notification function. In order to ensure that the intervention and control group will receive equal attention from our research team, we shall send a text about HK FitNuts and general exercise information to participants in the control group three times per week. Same as participants in the intervention group, the control group will also be asked to provide their weekly app usage and PA pattern by completing an online log at the end of each intervention week."