Jenny Simpson will never run again after cardiac arrest and ARVC diagnosis

'My body was dying, but my spirit wouldn't give up'

The 39-year-old shared the news on Instagram on Thursday, explaining that she collapsed in June while pacing a mile group at a running event in North Carolina.

Bystanders performed CPR and used a defibrillator before emergency services arrived and took her to hospital in Raleigh. She then suffered a second cardiac arrest in hospital and was placed on life support before being transferred to Duke Hospital for further treatment.

Simpson was subsequently diagnosed with arrhythmogenic right ventricular cardiomyopathy (ARVC), a genetic condition that affects the heart muscle and its electrical system.

The disease can cause heart muscle cells to be replaced by fatty and scar tissue, weakening the heart and increasing the risk of dangerous abnormal heart rhythms

What Jenny Simpson said about her diagnosis

"My heart was severely injured and stunned. My lungs struggled too," Simpson said. "My future is an incredible gift. It's hopeful, and it will continue to have great purpose. But my diagnosis also means it would be dangerous for me to return to running. That chapter has ended. Thankfully, my story hasn't."

Simpson leaves behind a career that saw her become world champion in the 1500m in 2011, before adding silver medals at the 2013 and 2017 World Championships. She also made history at the Rio 2016 Olympics, where she won bronze in the event, and competed at three consecutive Games from 2008 onwards.

She eventually called time on her competitive career after the 2024 season, bringing an end to one of the most successful running careers in US middle-distance athletics.

"I'm profoundly grateful that I got to have the career I did," she added. "I experienced everything — from the trenches of training to standing on the top of the podium while our national anthem filled the stadium."