Ruth Chepngetich has responded to accusations of doping after smashing the world record for the fastest marathon ever recorded by a woman. The 30-year-old clocked a time of two hours, nine minutes and 57 seconds to storm to victory in Sunday’s Chicago Marathon and surpass Ethiopia’s Tigst Assefa’s previous record by almost two minutes.

As the Kenyan becomes the first woman to break 2:10, the running world is left wondering if the performance was down to her undoubted talent, hi-tech super shoes, modern energy drinks or something els