Stem Cell Recruitment in Exercised Skeletal Muscles of Older Women by Phytosteroid Rg1

The goal of this interventional study is to observe the effects of bone marrow stem cell behavior in skeletal muscle of women between 60 to 75 years old after a single moderate resistance exercise session. Plant sterol Rg1, a compound known to enhance stem cell infiltration following exercise in young men will be tested against a placebo in a double blinded crossover design. The main questions to be answered are: * Does Rg1 supplementation alter serum sex hormone levels in recovery from exercise? * Does Rg1 supplementation influence bone marrow stem cell differentiation in skeletal muscles of older women? Participants will: * Pre-test body composition, maximal leg strength, blood and muscle tissue. * One hour after taking the supplement, participants will perform 4 sets of 10 repetitions of 70% of maximal strength (1RM) leg press and have two thigh muscle biopsies (0 and 24 h after exercise). * Repeat the protocol one month later on the alternative supplement. Researchers will understand whether Rg1 improves recovery response to resistance exercise in post-menopausal women.