AGE AND GENDER RESPONSES TO STRENGTH TRAINING

Abstract

1527 Previous reports have concluded that muscle hypertrophic response to strength training (ST) is attenuated with age, but unaffected by gender. However, these comparisons have not been adequately addressed. To determine age and gender responses to ST, we studied the effects of a 9 wk unilateral, knee extensor ST program on both the trained and untrained quadriceps muscle group in 44 young (20-30 yr) and older (65-75yr) men and women. Muscular strength, thigh fat free mass (FFM), and total volume of the quadriceps muscle group (MV) were measured by 1 RM, DEXA, and MRI, respectively, in the trained and untrained legs of 11 young men, 11 young women, 11 older men, and 11 older women. Four sets of heavy resistance exercise was performed 3 times/wk on a Keiser K-300 leg extension machine. A 2x2 factorial ANOVA was used to determine age and gender effects using the difference between the changes in the trained and untrained legs. The ST program increased 1 RM strength, thigh FFM, and MV significantly more in the trained leg than in the untrained leg(all P < 0.05) for all age and gender groups. There was also a greater increase in both thigh FFM and MV in the young men compared to the young women(P < 0.05), and a greater increase in thigh FFM in the older men compared to the older women (P < 0.05). There were no significant differences in the increases of either thigh FFM or MV between the older and younger groups. Thus, in contrast to previous reports, these results show that the hypertrophic response to ST is greater in men than in women, but is not attenuated by age.