39-year-old collapsed during event in JuneAmerican won world title in 2011 Former 1500m world champion Jenny Simpson says she will not return to running after she collapsed during a track event in June.Simpson, a three-time Olympian and one of the most accomplished American female runners in history, was pacing a mile group at an event in North Carolina when she went into cardiac arrest. She was given CPR before she was rushed to hospital, where she was placed on life support due to issues with