Optimizing frailty care: an analysis of dual exercise targets and cognitive function among frail older adults

Cognitive decline is a significant concern among frail older adults. Although aerobic and resistance exercise are recommended, their implementation remains challenging due to reduced physical capacity and vitality in this population. Understanding how cardiorespiratory fitness (CRF) and muscle strength (MS) relate to cognitive function may inform targeted exercise prescription. This cross-sectional study examined their independent and combined associations with cognitive impairment in prefrail and frail older adults. We enrolled 4477 prefrail and frail older adults (mean age 72.2 years, 72.5% female). CRF was assessed by 2-min walk test, MS by handgrip strength, and cognitive impairment by Montreal Cognitive Assessment 5-min protocol. Logistic regression analysis examined relationship of CRF and MS with cognitive impairment. Three hundred fifteen (7.0%) participants had cognitive impairment. Higher CRF was independently associated with lower odds of cognitive impairment across quartiles (Q4 vs. Q1: OR = 0.15, 95% CI 0.08-0.29; p for linear trend < 0.001). The association with MS was attenuated after adjusting for CRF, with Q3 (OR = 0.65, 95% CI 0.45-0.94) and Q4 (OR = 0.66, 95% CI 0.45-0.97) statistically significant. Findings were consistent across prefrail and frail subgroups. Joint analysis revealed that high CRF with high MS had lowest odds of cognitive impairment (OR = 0.38, 95% CI 0.26-0.56) compared to low CRF with low MS, and high CRF alone conferred 56% lower odds than high MS alone. CRF and MS were significantly associated with cognitive impairment, with CRF showing stronger independent associations, suggesting CRF as a promising target for future exercise interventions to prevent cognitive decline in prefrail and frail older adults.