The International Association of Athletics Federations (IAAF) has come under intense fire since releasing its new “Eligibility Regulations for the Female Classification&rdquo. The rules have been called sexist, racist, unethical, and based on bad science, although the governing body is sticking to its guns. Under the new regulations, from November 1 some female runners with naturally high testosterone levels will be banned from competing over distances from 400 metres to the mile at international meets. The measures are based on a study it commissioned last year which concluded that “female athletes with high free testosterone (fT) levels have a significant competitive advantage over those with low fT in 400m, 400m hurdles, 800m, hammer throw, and pole vault”.