Woman the Hunter.

The estrogen receptor - the protein that estrogen binds to in order to do its work - is deeply ancient. Tellingly, in a separate study Mazen J. Hamadeh of York University and his colleagues found that males supplemented with estrogen suffered less muscle breakdown during cycling than those who didn't receive estrogen supplements. Given the fitness world's persistent touting of the hormone testosterone for athletic success, you'd be forgiven for not knowing that estrogen, which females typically produce more of than males, plays an incredibly important role in athletic performance. But the hormone estrogen, which females typically produce more of than males, actually plays a critical role in athletic performance. [Extracted from the article]