Abstract: Objective: To explore the influencing factors of exercise behavior of frail elderly live in a care institution. Methods: In-depth interview using phenomenological method was conducted with 12 frail elderly people in a care institution in Beijing from April to May, 2021, and Colaizzi's 7-step analysis method was used for data analysis based on the COM-B model. Results: Facilitators of exercise behavior included perceived exercise benefits, emotional support from major social relationships, variety of access to exercise knowledge, interpersonal interaction promoting. Barriers of exercise behavior included insufficient awareness of exercise, limited physical activity, poor state of illness, negative psychology of life status, environment constraints. Conclusion: The exercise behavior of the frail elderly is affected by a variety of factors, and the medical staff should take targeted measures to increase the participation of the elderly in exercise behavior to improve the weakness, and promote healthy aging.

Key words: care institution; elderly; frailty; exercise; influencing factor; qualitative research