Effect of the Active Aging-in-Place–Rehabilitation Nursing Program: A Randomized Controlled Trial

(1) Background: It is of great importance to promote functional capacity and positive lifestyles, since they contribute to preventing the progression of frailty among the older adults. The aim of this study was to evaluate the effect of active aging-in-place–rehabilitation nursing program (AAP-RNP) on the functional capacity and lifestyles of frail older adults. (2) Methods: This was a single-blinded, two-group, randomized, controlled trial of 30 frail older people enrolled at a Health-care unit in Portugal between 2021 and 2022. The duration of the program was 12 weeks, and the sessions took place at the participants’ homes. We used as instruments the Tilburg Frailty Indicator; Fried frailty phenotype; Senior Fitness Test battery; Barthel Index; Lawton Index; handgrip strength measurement; Tinetti Index; Individual lifestyle profile; and Borg’s perception of effort. (3) Results: Post-program, there was an improvement in multidimensional and physical frailty, functional capacity, balance, and perceived exertion (p < 0.05) in the experimental group. Among the older adults’ lifestyles, we observed significant improvements in physical activity habits, relational behavior, and stress management. (4) Conclusions: Rehabilitation nurses have a relevant role, and the AAP-RNP seems to be effective in improving functional capacity and lifestyles in frail older adults.