Frailty assessment and effect of physical activity interventions in older adults: a scoping review, meta-analysis,...

Population ageing is accelerating worldwide, leading to a rising prevalence of frailty, a potentially reversible condition. Physical activity (PA) is a promising strategy to mitigate frailty, but heterogeneity in its definition and assessment has led to wide variation in measurement tools and intervention approaches. This study aimed to map frailty assessment methods and PA interventions in frail and pre-frail older adults, and to evaluate their effectiveness using meta-analysis and meta-regression.

A scoping review was conducted in April 2025 using PubMed, Embase, and the Cochrane Library, including studies published up to 2024. Eligible studies were intervention trials involving adults aged ≥ 60 years, reported a PA program and a validated frailty assessment. Two reviewers independently screened and selected studies. Meta-analysis and meta-regression were performed on randomized controlled trials reporting Fried frailty scores. Mean differences were pooled using a random-effects model, with additional analyses to explore the influence of intervention characteristics.

A total of 163 studies were included. Frailty was assessed using 47 different tools, most frequently the Fried phenotype. Interventions were predominantly multicomponent, combining resistance, aerobic, balance, and flexibility exercises, typically delivered 2-3 times per week in supervised settings. Eighteen studies were included in the meta-analysis. Overall, PA interventions significantly reduced Fried frailty scores (MD = -0.71; 95% CI [-0.92, -0.49]; p < 0.0001). Baseline frailty level (p = 0.0125), session frequency (p = 0.01), and intervention context (p = 0.0008) significantly influenced outcomes.

Physical activity interventions are associated with reductions in frailty when assessed using the Fried phenotype. However, substantial heterogeneity in frailty assessment and intervention reporting limits comparability and clinical translation. Standardization of frailty measures and improved reporting of intervention characteristics are needed to optimize and implement effective PA strategies in older adults.