Author ORCID Identifier:

https://orcid.org/0009-0000-0940-3875

Date of Graduation

7-2026

Document Type

Dissertation

Degree Name

Doctor of Philosophy in Health, Sport and Exercise Science (PhD)

Degree Level

Graduate

Department

Health, Human Performance and Recreation

Advisor/Mentor

Gray, Michelle

Committee Member

Hammig, Bart

Second Committee Member

Butts, Cory

Third Committee Member

Howie-Hickey, Erin

Fourth Committee Member

Zhang, Jihong

Keywords

Alzheimer's; Cognition; Dementia; Muscle Mass; Physical Function; Strength

Abstract

Age-related declines in skeletal muscle health (SMH) and cognitive function are major contributors to disability, loss of independence, and reduced quality of life among older adults. Emerging evidence suggests that skeletal muscle and cognitive health may be interconnected through shared physiological mechanisms; however, the relationships between specific aspects of SMH and cognitive performance remain unclear. Therefore, the purpose of this study was to examine the relationships between SMH and cognitive performance among older adults and to determine whether SMH differs between cognitively healthy and cognitively impaired individuals after accounting for age and physical activity. A cross-sectional analysis was conducted using data collected from community-dwelling older adults aged 65 years and older. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA). SMH outcomes included measures of body composition (lean mass and fat mass), muscle strength (handgrip strength and quadriceps strength), and physical function (chair stand performance, peak power, peak force, gait speed, and six-minute walk distance). Pearson correlations and multiple regression analyses were used to examine associations between SMH variables and cognitive performance. Analyses of covariance (ANCOVAs) were conducted to compare SMH outcomes between cognitively healthy and cognitively impaired participants while controlling for age and physical activity. Weak-to-moderate relationships were observed between cognitive performance and several measures of physical function. In the overall sample, six-minute walk distance demonstrated the strongest positive association with MoCA score (r = .31), followed by physical activity (r = .28). Multiple regression analyses indicated that SMH variables collectively explained little variance in cognitive performance in the overall sample. However, among women, lean mass emerged as a significant positive predictor of cognitive performance, accounting for a meaningful proportion of variance in MoCA scores. Comparisons between cognitive groups revealed significant differences in chair stand performance (p = .041), peak power (p = .009), and six-minute walk distance (p = .005) after controlling for age and physical activity. Cognitively healthy participants demonstrated faster chair stand performance, greater lower-extremity power, and greater walking endurance than cognitively impaired participants. No significant group differences were observed for lean mass, fat mass, handgrip strength, or quadriceps strength. These findings suggest that physical function, particularly lower-extremity power and walking endurance, may be more strongly associated with cognitive status than measures of muscle mass or strength alone. Furthermore, lean mass may have a unique relationship with cognitive performance among older women. Collectively, these results support the potential value of SMH assessments as non-invasive indicators of cognitive health and highlight the importance of preserving physical function in aging populations.

Download

Share

COinS