Age-related declines in knee extensor strength and physical performance in healthy Hispanic and Caucasian women.
Hispanic women may undergo greater age-related reductions in physical functional capacity compared with Caucasian women. If so, a greater rate of decline in muscle strength with age could contribute. We tested this hypothesis in 82 healthy sedentary Caucasian (n = 37) and Hispanic (n = 45) adult women aged 21-78 years of similar socioeconomic status. Absolute one-repetition maximum (1-RM) strength of the knee extensors (KE) declined with advancing age in the Caucasian (r = -.55, p < .01) and Hispanic (r = -.45, p < .01) women; the rates of decline were similar in the two groups (-7% to 8% x decade(-1), p = .60). KE strength normalized for thigh fat-free mass (FFM) also declined with age in the Caucasian (r = .52, p < .01) and Hispanic (r = -.41, p < .01) women, the rates of decline being similar (-6% to 7% x decade(-1), p = .66). For all functional performance tasks (10-m walk, stair ascent, stair descent, and chair stand), performance time increased with advancing age (mean of four tasks vs age: Caucasian, r = .64, p < .01; Hispanic, r = .56, p < .01). Absolute and normalized KE 1-RM were inversely related to the mean time for the four performance tasks (r = -.34 to -.58, all p < .01). Normalized KE 1-RM was the best independent predictor of the age-related decline in task performance in both groups. These cross-sectional findings do not support the hypothesis that Hispanic ethnicity per se is associated with a greater decline in KE strength and performance tasks associated with KE strength in healthy women.
Schiller
B C
BC
Department of Kinesiology and Applied Physiology, University of Colorado, Boulder, USA.
Casas
Y G
YG
Tracy
B L
BL
DeSouza
C A
CA
Seals
D R
DR
D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D006630:Hispanic or Latino; D006801:Humans; D007717:Knee / Q000502:physiology*; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology*; D010809:Physical Fitness; D012016:Reference Values; D013848:Thigh; D013851:Thinness; D044465:White People