Becky James, the two-time Olympic silver medallist and former world champion, has announced her retirement from cycling aged 25. James won two gold medals and two bronze medals at the 2013 Track Cycling World Championships in Minsk, Belarus, aged 21. James responded to claim silver medals in the sprint
Fredericks, a multiple Olympic sprint silver medallist and a rising star among international sports administrators until this year, was temporarily banned in July. Fredericks has repeatedly denied any wrongdoing.