Disputing long-held beliefs that some female athletes' irregular menstrual cycles are caused by intense training regimes, a new Swedish study is reporting that many hyper-athletes with "menstrual disorders" may also suffer from polycystic ovary syndrome, which, incidentally, can make them better athletes. The syndrome, which is quite common, increases production of male hormones, making it easier for women to increase muscle mass and absorb oxygen. While 1 in 5 women in the general population has the syndrome, some 37% of women training for the Olympics and surveyed in the Swedish study had polycystic ovaries. [BBC]