The Ironman athlete who recovered from COVID-19 after spending days on a ventilator and heart-lung bypass machine is back in training with plans to complete another extreme triathlon this fall.

Ben O'Donnell, 38, said he wants his recovery to give hope to others and to raise money for COVID-19 relief via the Ironman Foundation's Ironaid program.

"If I can show I can come back and get to this point," he said, "that might do more for COVID fundraising, and just give people more hope."

O'Donnell's COVID-19 case was memorable because he was the first relatively young, healthy Minnesotan to require intensive care for the infectious disease. Most of the COVID-19 hospitalizations and deaths in Minnesota involve people 50 or older, but O'Donnell offered proof that the pandemic presented a risk to younger people as well.

The chemical company executive spent days on a ventilator and on an ECMO heart-lung bypass machine due to the level of damage and fluid buildup in his lungs that prevented him from breathing on his own. According to an Extracorporeal Life Support Organization database of global COVID-19 patients who came off bypass machines, only 55% survived their hospitalizations.

Recovery was slow after his treatment at the University of Minnesota Medical Center from March 9 to April 6. The Anoka County man needed supplemental oxygen just to walk to the mailbox at first but no longer needs that support during training.

O'Donnell can now run a 5K, swim a mile, and bike in one hour about 18 to 20 miles. The former college fullback has been shocked at the slow recovery of strength — only managing three pushups at a time so far — and has lingering symptoms such as numbness in one thigh.

He has signed up for the Ironman in Tempe, Ariz., in November that features a 2.4-mile swim, a 112-mile bicycle ride and a 26.2-mile marathon.

Endurance training is about pushing limits, and O'Donnell said he is trying to expand the length of his runs and bike rides by 20 to 30 minutes each week. However, he said he is paying attention to the heart rate and blood-oxygen levels on his watch.

"I do push it a bit but ... I'll shut it down if I see my oxygen levels are dropping," he said.

Severe COVID-19 can cause scarring and lung damage that can permanently reduce breathing capacity and athletic performance, and O'Donnell said he is braced for the possibility that he won't fully recover. On the other hand, he said he is actually ahead of his training regimen when he was healthy and did his first Ironman in Madison in 2017.

A chest scan in late July should give a better idea of O'Donnell's status.

Logging training hours has become harder with a full-time return to work, he said.

"It's more of a grind but it is my time to get away and just unplug and focus on getting healthy," he said.

O'Donnell said his family — including his wife and 4-year-old daughter — are downsizing to a smaller home with less lawn upkeep. The COVID-19 scare taught him to simplify and focus on things that matter most to his family.

O'Donnell said he is participating in research and donating his blood — which was found to be rich in antibodies following his infection. He cannot donate plasma that can be used to treat others, though, due to the number of blood transfusions he received during his hospitalization.

Given the lack of proof over whether people can be reinfected, O'Donnell said he takes nothing for granted and wears masks on errands.

"We just don't know enough," he said.

O'Donnell has raised just over $2,000 of his $10,000 goal for Ironaid. One project funded through that program repurposes new racing jerseys into non-sterile masks that can be donated to protect people most vulnerable to COVID-19 due to their age or underlying health conditions.