Under new regulations imposed by the International Association of Athletics Foundation or ‘IAAF’, from 1 November 2018 women with naturally high testosterone levels will be required to forced to either stop competing, or to take medication to reduce their testosterone level for six months, before being eligible to run in certain international athletics events. Ryan Storr, Lecturer in Sport Development at Western Sydney University, joined us to explain these controversial new rules, and the complex debate raging around them.