Strength and fitness are associated with large artery hemodynamics in older adults

Introduction: Aging is associated with impairments in vascular health and subsequent increases in cardio- and cerebrovascular disease risk. Healthy lifestyle behaviors such as regular exercise, can improve muscular strength and aerobic fitness, both of which are independently linked to reduced disease risk with aging. The exact mechanisms by which muscular strength and aerobic fitness maintain vascular health are unclear but may stem from improved large artery hemodynamics. The purpose of this study was to examine the association between muscular strength and aerobic fitness on vascular hemodynamics in older adults. We hypothesized higher levels of muscular strength and aerobic fitness would be associated with greater carotid wave reflection, and lower carotid characteristic impedance and pulsatility in older adults. Methods: 208 Older adults (74±5 yrs, 56% female) underwent vascular assessments and completed handgrip dynamometry and a timed 400-meter walk test to characterize muscular strength and aerobic fitness, respectively. Vascular measures included carotid artery characteristic impedance, blood velocity pulsatility, and wave reflection index via tonometry, Doppler ultrasound, and integrated pressure-flow analyses. Multiple linear regression was utilized to assess associations between grip strength, aerobic fitness, and large artery hemodynamics, with age, sex, body mass index, and hypertension, cholesterol, and smoking status as covariates. Results: Carotid wave reflection index was positively associated with aerobic fitness (β=0.20, p=0.02), while grip strength was inversely associated with carotid characteristic impedance (β=-0.20, p=0.03). No significant associations were detected between strength or fitness with carotid pulsatility (β=0.11-0.16, p=0.19-0.25). Conclusion: These data indicate that higher (i) aerobic fitness is associated with greater carotid wave reflection, a key hemodynamic mechanism that may help attenuate transmission of pulsatile hemodynamics into the brain that can damage the sensitive cerebrovasculature, and (ii) grip strength was associated with lower carotid characteristic impedance, which may help preserve cerebral blood flow and reduce transmission of pulsatile hemodynamics into the brain. Taken together, fitness and strength may attenuate different aspects of vascular aging (wave reflection versus characteristic impedance) in older adults, ultimately benefiting cardiovascular risk and brain health. This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.