A cluster randomized controlled trial of a positive physical activity intervention

Area of Science:

• Public Health
• Behavioral Science
• Exercise Science

Background:

• Global urbanization and technological advancements have led to reduced energy expenditure, a significant public health concern.
• The Positive Physical Activity (PPA) intervention was developed to address declining physical activity levels in families.
• PPA uses positive affective attitudes to promote enjoyable physical activity, overcoming common barriers to behavior change.

Purpose of the Study:

• To evaluate the effectiveness of the PPA intervention in promoting physical activity and fitness among Hong Kong families.
• To assess the impact of Zero-Time Exercise (ZTEx) as a 'foot-in-the-door' approach within the PPA framework.
• To explore participants' motivational, interpersonal, and affective experiences with the intervention.

Main Methods:

• A citywide, cluster randomized controlled crossover trial was implemented using a community-based collaborative approach.
• 1,983 participants from 1,467 families across all 18 districts of Hong Kong were recruited.
• Data were collected via structured questionnaires and physical fitness assessments at baseline, 1-month, and 3-month follow-ups.

Main Results:

• The PPA intervention significantly increased Zero-Time Exercise (ZTEx) and family-based ZTEx at 1-month and 3-month follow-ups.
• Improvements in balance and endurance were observed at the 3-month follow-up.
• Qualitative data from focus groups corroborated intervention effectiveness and provided insights into participant experiences.

Conclusions:

• The PPA intervention is effective in enhancing physical activity and fitness levels in families.
• The community-based collaborative approach proved successful in engaging stakeholders and building capacity for program development.
• The findings highlight the potential of positive affective strategies in promoting sustained health behavior change.