The goal of the study is to evaluate the effectiveness of a family-focused, interactive, and theory-based intervention to reduce the sedentary behavior and increase physical activity, family communication and well-being of the participants.

The intervention is to use Zero-time Exercise, the positive psychology theme "Appreciation and Gratitude" [23, 24], and role modelling approach to get sedentary people to start exercising, increase levels of physical activity, family communication and well-being of the participants and their family members.

The intervention aims to encourage positive and sustainable health actions among participants and their family members.

Lack of physical activity is a behavioural risk for non-communicable diseases. The World Health Organization (WHO) reported that physical inactivity and unhealthy diets are two of the four main behavioural risk factors that contribute to non-communicable diseases. Globally, people who are overweight and obese, particularly if these people are physically inactive. They are at risk for morbidity and mortality.

Hong Kong-specific data demonstrates that many people cannot meet World Health Organization targets for physical activity. The Hong Kong Behavioural Risk Factor Survey reported that, for the seven days prior to the survey, about half (52.0%) of adults aged 18-64 had not done any moderate physical activity. Overall, only 37.5% of the respondents met the WHO's recommended physical activity level of at least 150 minutes of moderate or 75 minutes of vigorous physical activity a week for adults.

There is emerging evidence of effective behavioral interventions to decrease sedentary behavior. Some studies focused on reducing screen time or active workstations that encourage standing at the computer. Others focus on increased use of stairs instead of lifts. These interventions used behaviour change techniques such as goal-setting and behavioural self-monitoring. As previous approaches have not shown promising results, new approaches are needed to reduce sedentary behaviour and increase exercise or physical activity.

The goal of the study is to evaluate the effectiveness of a family-focused, interactive, and theory-based intervention to reduce the sedentary behavior and increase physical activity of the participants.

The intervention is to use Zero-time Exercise, the positive psychology theme "Appreciation and Gratitude", and role modelling approach to get sedentary people to start exercising, increase levels of physical activity, family communication and well-being of the participants and their family members. The intervention aims to encourage positive and sustainable health actions among participants and their family members.

Needs assessment and focus group interview will be conducted before program design and after conducting the training, respectively. Process evaluation will be performed to evaluate the process of each component of the program. Qualitative and quantitative assessments will be used to evaluate the effectiveness of this Zero-time Exercise intervention.

Inclusion Criteria:

1. Parents with at least on child between 3 and 18;
2. Parents with at least primary school educational level:
3. Parents who can read and write Chinese.

Exclusion Criteria:

1. People with a serious health condition that might prevent them from participating in physical activity;
2. Parents who do not have a child between 3 and 18.