A proposed exercise trial for long COVID is being criticized by some of the patients the government-funded researchers want to study.
The trial is part of the Researching COVID to Enhance Recovery (RECOVER) initiative, funded by the government for $1.15 billion over four years. It aims to study long COVID and help find treatments for the millions of people experiencing a range of long-lasting symptoms, including extreme fatigue, brain fog and shortness of breath.
The study is under one of five trial platforms that the National Institutes of Health and Duke Clinical Research Institute plan to start in the summer and fall. Each trial platform will study a different cluster of long-COVID symptoms and test a range of interventions.
The exercise study protocol has not been finalized, but it will test physical therapy at different intensity levels, tailored to the patient’s capabilities, and aim to improve endurance, said Adrian Hernandez, executive director of Duke Clinical Research Institute.
He called early research on physical therapy “promising” but declined to cite specific studies. He estimated that exercise-based interventions could help up to half of long-COVID patients.
Some long-COVID advocates, however, say that any exercise trial could be potentially dangerous for long-COVID patients with myalgic encephalomyelitis (ME/CFS), also known as chronic fatigue syndrome.
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Exercise and its impact on people with ME/CFS
Studies show that people with ME/CFS don’t have the same response to physical exertion as healthy individuals, and many ME/CFS patients report a worsening of symptoms after even small amounts of activity. This crash is called post-exertional malaise.
Some ME/CFS patients say that, over time, continuously pushing past their limits has caused them to permanently worsen. It’s unclear exactly how many long-COVID patients have ME/CFS, but some researchers estimate that about half develop ME/CFS.
Advocates now worry that long-COVID patients with ME/CFS could be similarly harmed if they take part in any exercise study.
Long COVID Justice, a patient advocacy group, started a petition at the end of last year calling for the NIH trial to be stopped. #MEAction, a nonprofit advocacy group for people with infection-associated chronic illness, also sent two letters, in February and March, to a RECOVER committee calling for an end to the trial.
If the trial begins, #MEAction asked for any patient with ME/CFS or post-exertional malaise to be excluded, arguing that exercise would not be helpful to this population.
“Worst-case scenario, this would harm a lot of people,” said #MEAction’s U.S. advocacy director, Ben HsuBorger.
Hernandez said researchers plan to educate participants about post-exertional malaise and carefully screen for the condition before proceeding. The study is voluntary, he said, so participants can decline to participate or can drop out. An independent committee has reviewed the study to ensure its safety, and institutional review boards will also check the study to make sure it is safe and ethical, he said.
There are over 200 symptoms associated with long COVID, and some symptoms, such as exercise intolerance, could have different root causes, Hernandez said. With such a wide spectrum of symptoms, it’s difficult to find one intervention that works for everyone, he said.
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ME/CFS’s complicated research history
JD Davids, the co-founder and co-director of Long COVID Justice, said he fears that NIH’s exercise trials for long COVID continue the scientific community’s long history of mishandling ME/CFS research.
Davids, who has long COVID and ME/CFS, said many patients like himself have felt shut out of conversations or ignored by researchers. “I appreciate the involvement of people with ME who understand the stakes here, who are doing everything possible to not let that history repeat itself,” he said.
Historically, some patients say, doctors have trivialized ME/CFS or denied that it is a real condition and dismissed patients as having anxiety.
Research on the condition has also been scarce: A 1999 audit revealed that the Centers for Disease Control and Prevention spent much of its funding for ME/CFS research on other diseases, and one study found that when taking disease burden into account, ME/CFS has been one of the lowest-funded diseases for research by NIH.
One of the largest studies involving ME/CFS has been a subject of controversy. The study published in the Lancet found that cognitive behavioral therapy and graded exercise therapy (which involves a gradual increase in activity over time) could be beneficial for patients with ME/CFS.
But the study has been widely criticized for changing its outcome measures midtrial without a clear rationale and using flawed data collection methods. While the lead author of the Lancet report stands by the results of his study, concerns over the safety of graded exercise therapy prompted the CDC to remove it as a recommended treatment for ME/CFS.
In contrast, another study found that most ME/CFS patients had worse symptoms after graded exercise therapy.
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Exercise and long COVID
Some long-COVID patients have been told that they have ME/CFS and should avoid exercising past their limits.
A large number of long-COVID patients, however, have also developed an autonomic nervous system disorder called POTS, or postural orthostatic tachycardia syndrome. Physical therapy is routinely recommended as a standard intervention that can help manage POTS and is now being recommended to some long-COVID patients with POTS.
David Systrom, an assistant professor of medicine at Harvard Medical School, believes that there is a big overlap between POTS, ME/CFS and long COVID. Systrom is co-chair of a RECOVER task force looking at commonalities between long COVID and other post-viral syndromes. It’s unclear how many long-COVID patients have ME/CFS, POTS or both conditions, he said.
In independent research, he and other researchers found that people with POTS, ME/CFS and long COVID all experience blood flow abnormalities. He believes issues with the autonomic nervous system, which regulates involuntary functions such as heart rate, blood pressure and digestion, contribute to all three conditions.
Exercise training, he said, could help retrain blood vessels to behave more normally. But he cautioned that some preliminary research shows that inflammation in patients with ME/CFS can get worse as a result of exercise.
Systrom typically treats his long-COVID patients with medications to improve their autonomic nervous system function or reduce inflammation before suggesting any type of exercise.
“If we get patients properly medicated and feeling better, we have found that they are able to gradually and carefully advance their exercise programs without precipitating crashing,” he said. “That distinction is hugely important.”
Another study, in the Journal of Applied Physiology, found that individualized exercise training under the supervision of a medical professional helped reduce long-COVID symptoms and improve overall health for most patients. The researchers cautioned, however, that the benefits could not be generalized and that other factors such as vaccines and nutrition could have affected the findings.
Matt Durstenfeld, a cardiologist and assistant professor at the University of California San Francisco School of Medicine, has done research showing that people with long COVID cannot properly increase their heart rates during exercise.
“We don’t know what the role of exercise is,” Durstenfeld said. “That’s why, scientifically, it’s really important that we study it in a rigorous fashion, especially when there are competing viewpoints in the community, where some people think exercise is extremely harmful and other people think exercise is the key to recovery.”
Exercise, though, is unlikely to cure long COVID, and it’s debatable how much funding should be directed toward studying exercise vs. studying a cure, said Durstenfeld, who collects data for RECOVER and whose salary is partly funded by NIH funds paid to UCSF.
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Prioritizing exercise over other potential treatments
Some of the criticism about NIH’s exercise trial is about priorities, says Charlie McCone, 33, of San Francisco, who is a patient representative for RECOVER.
McCone said he developed POTS and post-exertional malaise following a coronavirus infection in March 2020, which worsened after a second infection in September 2021. Physical therapy is one of the few treatments being offered to long-COVID patients, and while it is widely available, it isn’t helpful for many, he said.
Last fall, a single day of strength training exercise at a long-COVID clinic caused him to crash to the point of not being able to get out of bed for four weeks, McCone said. He is now desperately waiting for better treatment options and believes that the NIH exercise trial will not significantly change the landscape of available treatments.
McCone argued that because there is limited funding to study long COVID and NIH plans to run only five trial platforms, researchers should prioritize studying potential cures or promising pharmaceutical interventions.
“How much longer are we going to be sick and have to watch this agonizing process unfold?” he asked. “When we’re prioritizing these kinds of trials and then we’re being told that help is on the way, it just doesn’t really feel like it.”
Hernandez, the executive director in charge of the trials, said medical professionals shouldn’t be prescribing exercise just because it is convenient and argued that there needs to be more evidence for this practice.
If exercise ends up being helpful, having evidence from a large scientific trial such as this one will help ensure that the intervention is widely available and covered by insurance, he said. And, if exercise ends up not being helpful, he believes patients have a right to know.
He said he understands that people are impatient for a cure, but he cautioned that scientific research is usually a slow process and that studies don’t always result in a breakthrough.
“Given what long COVID is and science is hard, we all have to be prepared that it’s going to take time to get the best answers,” he said.