At first, the nurse, who was vaccinated, did not think much about her shortness of breath. By November, she was slowly alternating a couple of good running days with ones “where I felt like I was coming apart,” she said, and was using a long-acting albuterol inhaler prescribed by her primary care doctor, which gave some relief.
Her heart was also beating faster, she said, something she hadn’t been concerned with early in her bout with covid-19, thinking that it was because of her illness. “My heart rate was so high, even at rest. It was getting high just from my getting up from the couch,” McDonnell said. “And I just wasn’t listening to myself.”
McDonnell’s doctor suggested she visit the Center for Post-Covid Care and Recovery, which was established in spring 2021 at National Jewish Health in Denver. In January, researchers there found through exercise testing that covid-19 alters how cells function in some people. Their study concluded that mitochondria — often known as the powerhouse of cells responsible for generating energy — did not function properly in patients with post-covid syndrome, more generally known as long covid — a term for symptoms that linger for weeks and months after a coronavirus infection.
The study suggested that many of those tested had fatigue out of proportion to work rate or the intensity of the exercise, said one of its co-authors, J. Tod Olin, a pulmonologist and director of the National Jewish Health Exercise & Performance Breathing Center. “So it feels like ‘I’m more tired than I should be,’ ” Olin said, despite the distance, speed or duration of exercise. For these patients, he said, “it looked like this part of the cell, the mitochondria — which is central to how muscles function — it appears that they were just less efficient at using the fuel.”
Another study conducted by researchers at the Yale School of Medicine found that there was a reason some patients who had covid and had no previous cardiopulmonary conditions were left feeling excessively tired after exercise, even as they recovered.
“These covid patients [with exercise intolerance] often have had mild disease,” said Phillip Joseph, associate director of the Yale Pulmonary Vascular Disease Program. They stay at home for a few days and then go back to work or their normal life, Joseph said, “but they have persistent exertional symptoms, and they often come through the post-covid clinic or referring provider with a whole slew of tests that are normal. Their pulmonary function tests are normal. An echocardiogram that’s normal.”
By inserting a small catheter in the wrist artery during exercise, Joseph and a team of researchers assessed how much oxygen the body absorbs throughout exercise. Many of the patients had been athletes in the past and were absorbing less oxygen post-covid, Joseph said. “There is some kind of abnormal flow across the muscle bed where oxygen is just not being delivered appropriately or absorbed appropriately,” he said. The mitochondria “don’t absorb oxygen.”
Joseph said this “post-exertional malaise” that previously active covid patients experience after running or other exercise is similar to the way patients with myalgic encephalomyelitis (also known as chronic fatigue syndrome or ME/CFS) feel after exercise. “There’s an inflammatory cascade that happens after they exercise called post-exertional malaise,” he said. “They have to lay on their couch for hours to recover.”
Many runners are suffering from long covid, which researchers are studying to find effective treatments and a cure.
They include Stephen Haskins, a marathoner and an anesthesiologist at Hospital for Special Surgery, 40, who contracted the coronavirus during the peak surge in New York City in March 2020. Haskins, who had two weeks of covid and a bout of pneumonia “that hit me a lot harder than I thought it would,” is slowly recovering. He credits deciding to get back into shape and train for marathons in 2017 for helping him battle the illness more effectively.
“When I finally got back onto the wards and in the ICU and I saw 30-some-year-old patients who were intubated and some of them were dying, it really kind of changed my perspective,” he said. “From a certain perspective, I felt like running might have saved my life.”
Longtime ultrarunner James Tenney, 57, of Las Vegas had a mild case of covid from the omicron variant in December. “It was all above my neck,” he says, “nothing respiratory.” Two months later, Tenney, who has been a runner for 35 years and who was vaccinated and had a booster shot, ran the Jackpot Ultra, a 100-miler in Las Vegas.
“I don’t think I was as crisp this year as previous” 100-milers, he said. “It was more of an 80 percent effort rather than 100 percent, because for me, anything beyond 70 miles is all mental. I had it in my head. ‘Oh, I hope, I hope covid doesn’t affect me,’ which is doomsday right there.’ ”
Physicians who treat patients with covid say the experience of the illness differs for each person. But for those looking to return to exercise, the advice is the same: Take it slow.
Theodore Strange, chair of medicine at Staten Island University Hospital, said the January guidelines published by the American College of Cardiology recommend a gradual return to exercise for recreational athletes. “As long as patients who had covid are asymptomatic of symptoms like chest pain and shortness of breath, returning to exercise is not an issue, but one should take their time getting back up to a regular training schedule,” he said. “If any symptoms do occur, then one must cut back and restart running at a slower pace.”
He recommends the 50/30/30/10 rule in guiding a return to running, absent of symptoms. Normal mileage should be reduced by 50 percent the first week, then by 30 percent the following week and so on. By the fifth week, runners should be able to resume normal training, he said. But “if clear cardiac symptoms develop when returning to running, such as chest pain, excessive shortness of breath, lightheadedness or faintness,” people should get evaluated, Strange said.
Joseph said he tells patients “to try to know what your limit is in terms of when you are going to develop those post-exertional symptoms, and exercise to just below that limit.” They could then gradually increase that over the course of weeks to months “instead of pushing yourself to the limit, to breathlessness,” he said. “That might actually be harmful because it tends to set you two steps back.”
McDonnell is working with Olin to open up her vocal cords to improve her breathing and strengthen her reduced lung capacity. “We’ve been on the stationary bike, the treadmill, walking and running,” she said, adding that some days she can walk or hike progressively longer distances, but on other days even household tasks are tiring. “My heart is 100 percent okay,” McDonnell said. “My lungs will recover. The decreased capacity is something that they’ve seen dissipate for pretty much everybody.”
McDonnell, who was later diagnosed with asthma, said she does not know whether it will be a temporary or permanent illness. “But it’s also a manageable and treatable condition that many people have,” she said.
She had two blood clots and scarring on her lungs as a result of covid, she said, but blood thinners are “significantly helping” her feel better and hike longer distances. “It does feel like there’s a light at the end of the tunnel,” McDonnell said, “and I can see longer hikes this summer and maybe even some running here and there.”
Haskins got back into running about six weeks after covid and completed a half-marathon, though there were lingering effects. “It’s a very unique disease,” he said.
“Everyone has their own set of symptoms. Like I never lost smell and taste, but I had a bad headache and I had brain fog for like six months and really severe body aches,” Haskins said. “That got better. But I definitely took a big hit to the lungs.”
Triathlete Marilyn Stebbins, 60, a pharmacologist at the University of California at San Francisco, had the first documented case of the coronavirus in Yolo County, Calif., in March 2020. Her illness was so severe that her husband “really thought I might die,” she said. She went from slowly walking circles in her backyard to running, with plans for her first post-covid marathon in August.
“I think the beauty of trail running is that I’m not out there to win it. I’m out there for the adventure,” she said. “And I feel like if I have to walk up a hill, I walk up.”