Intervention study of Active Video Games on sedentary children's aerobic fitness, physical activity level and exercise-related self-efficacy

Background: 22% of Chinese primary children are catgorized as overweight/obese and currently, they are doing very little exercise [1]. Sedentary behaviors such as children's screen time (TV viewing, non-active video games) are thought to be a major origin of this outcome. Information communication technology provides a platform to activate more physical interaction betwwen the children and the screen. This AVG may be able to replace the traditional non-active video games [2]. However AVG studies are still providing mixing results on this research question and need more scientific evidence.

Aims: To determine the effect of a prescribed AVG intervention on children’s aerobic fitness compared to usual PA. Primary outcome: Exercise capacity (maximal oxygen uptake; VO2max) assessed with a 20-meter shuttle run field test at 12 weeks. Secondary outcomes: VO2max at 24 weeks, change in objective measured PA assessed at 12- and 24 weeks and self-reported exercise-related self-efficacy, screen time consumption, competence to be active and enjoyment.

Design: A standard two-arm parallel, single-blinded, randomized control trial

Participants: Chinese primary students will be recruited from schools in Hong Kong. Inclusion criteria: 1) Aged 10-12 years old; 2) Play video games ≥ 2 hours/week; 3) have no contraindications to perform PA.

Intervention: Children randomized to the intervention will participate in an AVG intervention three times per week for 12 weeks, in addition to their usual activity levels. Each exercise session will last 60 minutes and the research team will prescribe updated active video games consistent with moderate-vigorous intensity.

Control: The control group will continue with usual PA alone and will not receive the AVG intervention. Sample size: 80 participants will provide 90% power at 5% level of significance to detect a group difference of 3 ml/kg/min in change of peak VO2max from baseline to the end of intervention period, assuming a standard deviation of 4 ml/kg/min.

Analysis: All analyses will be conducted using SAS version 9.2 and R version 2.14.0, following the principle of Intention to Treat, with all randomized participants. Repeated measures mixed model will be used to investigate the intervention effect on primary and secondary outcomes, adjusting for baseline characteristics and correlation between repeated observations.

Significance: This will be the first study to provide definitive evidence for the impact of a prescribed AVG intervention on physical fitness and PA levels. If effective, this research will provide much needed evidence to inform health professionals how to incorporate technological approaches to enhance health-promoting behaviors.