The Effects of Strength Training on Regional Body Composition in Older Adults: Sex and Race Comparisons

Abstract

Purpose: To examine the influence of sex and race on the effects of strength training (ST) on thigh muscle volume (MV), mid-thigh subcutaneous fat (SCF) and intermuscular fat (IMF). Methods: One hundred and eighty-one previously inactive healthy Caucasian (N=117), African-American (N=54), and other (N=10) men (N=82) and women (N=99), aged 50-85 yrs, underwent ~10 weeks of unilateral knee extension ST. Results: Training-induced increases in absolute MV were significantly greater (P < 0.01) in men than in women. There were significant increases in MV within each race (P < 0.001); but no significant differences between races. There were no significant changes in SCF and IMF whether sex and racial groups were separated or combined. In addition, there was no sex by race interaction for changes in MV, SCF, or IMF with ST. Conclusion: Ten weeks of unilateral strength training does not alter subcutaneous or intermuscular fat regardless of sex or racial differences. Although men exhibit a greater muscle hypertrophic response to strength training compared to women, the difference is small. Race does not influence this response.