Do sex or race differences influence strength training effects on muscle or fat?
OBJECTIVE
To examine the influence of sex and race on the effects of strength training (ST) on thigh muscle volume (MV), midthigh subcutaneous fat (SCF), and intermuscular fat (IMF).


METHODS
One hundred eighty-one previously inactive healthy Caucasian (N = 117) and African American (N = 54) men (N = 82) and women (N = 99), aged 50-85 yr, underwent about 10 wk of unilateral knee extension ST. Ten subjects were neither Caucasian nor African American and were, therefore, not included in the race analysis. Quadriceps MV and midthigh SCF and IMF cross-sectional area were measured with computed tomography before and after ST. Sex and race comparisons were made with a 2 x 2 (sex by race) analysis of covariance.


RESULTS
Training-induced increases in absolute MV were significantly greater (P < 0.001) in men than in women, though both sex groups increased MV significantly with ST (P < 0.001), and the relative (%) increases were similar. There were significant increases in MV within race groups (P < 0.001), but no significant differences between races. There were no significant changes in SCF or 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.


CONCLUSIONS
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 than do women, the difference is small. Race does not influence this response.
Walts
Cory T
CT
Department of Public and Community Health, University of Maryland, College Park, MD 20742-2611, USA.
Hanson
Erik D
ED
Delmonico
Matthew J
MJ
Yao
Lili
L
Wang
Min Qi
MQ
Hurley
Ben F
BF
D050154:Adiposity / Q000502:physiology*; D001741:Black or African American; D000368:Aged; D000369:Aged, 80 and over; D001823:Body Composition; D005080:Exercise Test; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D010865:Pilot Projects; D012737:Sex Factors; D050151:Subcutaneous Fat / Q000502:physiology; D014481:United States; D014891:Weight Lifting / Q000502:physiology*; D044465:White People