Exploring Intrapersonal Determinants of Older Adults' Group Exercise Engagement in Taiwan: A Theory of Triadic...

As global population ageing accelerates, sustaining engagement in health-related activities has become a key strategy to promote healthy ageing and maintain quality of life in Taiwan. To address this issue, the present study draws on an established theoretical framework to offer a culturally sensitive and practice-oriented interpretation of regular health-promoting behaviours, thereby informing actionable strategies for health practitioners. This qualitative case study, grounded in the Theory of Triadic Influence, examined perspectives on the determinants that shape older adults' long-term engagement in group-based exercise. We conducted individual interviews with five participants who had consistently attended group exercise programme for over five years. By focusing on six personal determinants: personality, sense of self, locus of control, self-determination, general skills, and self-efficacy, we explored the commonalities that caused or explained those older adults' sustained participation. The findings revealed several shared factors, including self-directed motivation, internalised agency, and awareness of physical decline, which collectively supported sustained engagement in health-promoting behaviours. In contrast, personality traits, self-concept, and perceived control exhibited considerable diversity among participants. The study further offered culturally grounded interpretations of these divergent perspectives, highlighting how individual values and motivations were shaped by sociocultural contexts. This study highlights the need for practitioners to consider diverse personality traits and emotional sensitivities, rather than assuming all participants are extroverted. Supporting individual progress through clear guidance can enhance self-efficacy and foster continued participation. Emphasising small personal achievements over immediate performance may help reduce self-doubt and prevent disengagement.