According to the Health Belief Model (HBM), one's intention to engage in physical activity (PA) is strongly and favourably related to their actual PA behaviour (Etheridge, Sinyard, & Brindle, 2023; Kagee & Freeman, 2017). According to a meta-analysis that looked at the connection between PA intention and conduct, 54% of those who had the intention to be active did so, and just 2% of people who initially had no intention of engaging in PA later modified their behaviour (Rhodes & de Bruijn, 2013). Therefore, having PA intention is a crucial and helpful step to participate in PA(Webb & Sheeran, 2006).

Digital games include TV or console games, PC games, portable games, and others. Such games have recently been employed as teaching, learning, and training aids in a variety of contexts, including medical education (Rosenberg et al., 2010). Previous research has shown that motion sensor video games have positive effects on promoting healthy lifestyles including engagement in physical activity and disseminating health-related knowledge (DeSmet et al., 2014; Foley & Maddison, 2010; Lenhart, Kahne, Middaugh, Evans, & Vitek, 2008). Meanwhile, video games (at least once/day for 1 week) had positive effects on individuals' well-being and family relationships. (Foley & Maddison, 2010; Halbrook, O'Donnell, & Msetfi, 2019). Drawing on the HBM, playing digital game could be the cue to action which increases people's intention to engage in physical activities.

Our study aims to fill the gap by examining the effectiveness of motion-sensoring game-based intervention in increasing the intention of performing PA, as well as personal and family well-being.

Health promotion refers to the process through which individuals are empowered to enhance their control over their health and work towards its improvement (Smith, Tang, & Nutbeam, 2006). The primary obstacles encountered in prior health promotion initiatives predominantly involve participant engagement and the allocation of adequate resources for execution (Korda, 2013). Owing to the rapid digital transformation in recent decades, digital games are becoming increasingly popular approaches for health promotion that could cover the above challenges.

Regular physical activity is proven to help prevent and manage noncommunicable diseases (NCDs) such as heart disease, stroke, diabetes and several cancers. It also helps prevent hypertension, maintain healthy body weight and can improve mental health, quality of life and well-being. Intention is such a strong psychological predictor of behaviour including PA, as a result, PA intention has been an important and useful precursor to PA participation.

Therefore, our study aims to explore the effectiveness of motion-sensoring game-based intervention in increasing intention to perform physical activity. The intervention is a kind of motion-sensoring game based on Nintendo Switch that can accommodate 1-4 individuals, engaging their entire bodies in the physical motions involved and will last 1-2 minutes each session. It is notable that our project apps, a kind of mobile game, will be a placebo that was developed to promote family well-being in Hong Kong, has been applied in previous community events and received high satisfaction and positive feedback from both community participants and NGO social workers. We hypothesize that the motion-sensoring would promote the intention on participating in PA, as well as self-perceived personal and family well-being.

The primary objective is to promote the intention to perform physical activity. The secondary objectives are to enhance the knowledge of PA and to enhance their personal and family well-being.

Inclusion Criteria:

• Chinese speaking
• Able to complete the questionnaire
• Aged 18 or above

Exclusion Criteria:

• People with serious health conditions that might prevent them from participating in sensor-motion video game and mobile game