Michael Johnson says athletics 'in danger of losing credibility'

Eight-time world champion Michael Johnson says the sport of athletics is "in danger of losing credibility" in light of the recent doping allegations.

Johnson admits the sport is transitioning through a "difficult time", but believes the issues need to be addressed before the sport falls further behind.

He stresses the importance of being vigilant and staying one-step ahead, to eradicate cheating in athletics.