Jenny Simpson will not return to running after cardiac arrest

Jenny Simpson, the 39-year-old American and former 1500m world champion, said she will not return to running after suffering cardiac arrest while pacing a mile group at a pop-up event in North Carolina in June. She announced the decision in an Instagram post on Thursday.

Simpson represented the USA at three successive Olympics from 2008 and won a bronze medal at the 2016 Olympic Games in Rio. She claimed 1500m gold at the 2011 World Championships and took silver in the same event at the 2013 and 2017 World Championships.

Simpson collapsed during the North Carolina event and required CPR and the use of an automated external defibrillator before being taken to UNC Rex Hospital in Raleigh. At the hospital she went into cardiac arrest again and received further emergency treatment.

She said in her post: "My heart was severely injured and stunned. My lungs struggled too," and added: "I was diagnosed with a rare inherited heart condition called arrhythmogenic right ventricular cardiomyopathy (ARVC)."

The article’s explanation of ARVC notes it is a genetic condition in which the proteins that normally hold heart muscle cells together do not work properly. That process can cause heart muscle cells to die and be replaced by fatty tissue and scar tissue, leaving the walls of the heart chambers thin and stretched so the heart cannot pump blood around the body properly.

Simpson wrote: "My future is an incredible gift. It's hopeful, and it will continue to have great purpose." She also said: "But my diagnosis also means it would be dangerous for me to return to running. That chapter has ended. Thankfully, my story hasn't." Reflecting on her career she added: "I'm profoundly grateful that I got to have the career I did" and "I experienced everything - from the trenches of training to standing on the top of the podium while our national anthem filled the stadium."

Simpson retired from competitive racing at the end of the 2024 season.