(From Betterhumans). Increasing weakness and muscle decline are well known consequences of aging. Scientists are now delving into the biochemistry behind this degenerative process with an eye to preventing it. "There is a tight relation to how much muscle and strength a person has and (his or her) independence. There are many people who stand to benefit from this research. ... older women, aged 60 to 75, have difficulty building muscle mass despite weight training because they are unable to effectively reduce expression of the protein, myostatin. Myostatin is a protein made by muscle cells to block muscle growth. Scientists believe it plays a role in our early life, regulating muscle growth and ensuring normal development."
Link: http://www.betterhumans.com/News/news.aspx?articleID=2005-01-26-4