Greater muscle mass can generally produce greater muscle strength. However, whether higher muscle mass is associated with higher muscle quality (muscle strength relative to muscle mass) remains unknown. Furthermore, the nature of this relationship, and how their interaction determines the presence of functional impairments are unknown. This article aims to address these issues.Secondary data analysis including 1219 women aged 75 years and older of the Toulouse ÉPIDemiologie de l'OSteoporose cohort study. Body composition (dual energy X-ray absorptiometry), handgrip, and knee extension strength were assessed. Physical function was measured using the chair stand test as well as the usual and fast gait speed tests. Participants were also asked if they experienced any difficulty in performing functional tasks.Upper- and lower-body muscle quality (r = -0.42, P 1.27).This inverse relationship between muscle mass and quality implies that sarcopenic individuals have better muscle quality than nonsarcopenic individuals. Results also suggest that high muscle quality may compensate for low ASMI with respect to functional impairments. Physical activity may potentially be involved in this relationship.