Age and gender comparisons of muscle strength in 654women and men aged 20-93 yr

Lindle, R. S., E. J. Metter, N. A. Lynch, J. L. Fleg, J. L. Fozard, J. Tobin, T. A. Roy, and B. F. Hurley. Age and gendercomparisons of muscle strength in 654 women and men aged 20-93 yr.J. Appl. Physiol. 83(5): 1581-1587, 1997.To assess ageand gender differences in muscle strength, isometric, concentric (Con),and eccentric (Ecc) peak torque was measured in the knee extensors at aslow (0.52 rad/s) and fast (3.14 rad/s) velocity in 654 subjects (346 men and 308 women, aged 20-93 yr) from the Baltimore LongitudinalStudy of Aging. Regression analysis revealed significant(P < 0.001) age-related reductions in Con and Ecc peaktorque for men and women at both velocities, but no differences wereobserved between the gender groups or velocities. Age explained lossesin Con better than Ecc peak torque, accounting for 30% (Con) vs. 19%(Ecc) of the variance in men and 28% (Con) vs. 11% (Ecc) in women. Toassess age and gender differences in the ability to store and utilizeelastic energy, the stretch-shortening cycle was determined in a subsetof subjects (n = 47). The older women (mean age = 70 yr)showed a significantly greater enhancement in the stretch-shorteningcycle, compared with men of similar age (P < 0.01) andcompared with younger men and women (each P < 0.05). Bothmen and women showed significant declines in muscle quality for Conpeak torque (P < 0.01), but no gender differences were observed. Only the men showed a significant decline in muscle quality(P < 0.001) for Ecc peak torque. Thus both men and women experience age-related losses in isometric, Con, and Ecc knee extensorpeak torque; however, age accounted for less of the variance in Eccpeak torque in women, and women tend to better preserve muscle qualitywith age for Ecc peak torque. In addition, older women have an enhancedcapacity to store and utilize elastic energy compared with similarlyaged men as well as with younger women and men.