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.

Inclusion Criteria:

• sedentary, able to cease medications and supplements for 48 h before and 24 h after exercise session, medically sound for lower body moderate resistance exercise

Exclusion Criteria:

• use of insulin, sex hormone and immune-modulating medications, smoking and regular alcohol consumption

The National Research Institutes of Health (Taiwan) will conduct gene analysis on remaining muscle samples for aiding understanding of sarcopenia