'They end up having a lot more muscle damage than a healthy person would have,' says Charlton. The muscle biopsies taken after the exercise test revealed other troubling events.

The story doesn't end with mitochondria, either. 'That's really something future work will have to look at.'īiopsies carry clear signs of muscle damage 'There may be two ends of that spectrum,' he says. Systrom says it's possible both could be happening in long COVID patients. Meanwhile, the Dutch study suggests there could be 'intrinsic dysfunction' of the mitochondria's ability to produce energy, he says. In his own research, Systrom has found evidence of abnormal oxygen uptake by the skeletal muscles during peak exercise in both long COVID and ME/CFS patients, which indicates there's a problem with oxygen delivery to the mitochondria. 'They were able to link symptoms to these organic changes,' he says. David Systrom, a physician at Harvard Medical School and Brigham and Women's Hospital. Taken together, the results support the hypothesis that mitochondrial dysfunction plays a role in long COVID symptoms like fatigue and post-exertional malaise, says Dr. 'The mitochondria are operating at a severely reduced capacity compared to healthy people,' says Charlton. And they started producing lactate, a fuel of 'last resort' for cells, much sooner during exercise than those who were healthy, yet another sign that their cellular energy system had gone awry. Metabolites in the blood related to energy production were also severely reduced in long COVID patients. Using a technique called respirometry, the Dutch researchers oversupplied oxygen to the muscle tissue and found evidence the mitochondria weren't functioning properly Instead, something was making it hard for the muscle to take up the oxygen in the blood. 'Their baseline was already impaired and that dropped even lower with the maximal exercise,' says Charlton.Īs seen in other long COVID studies, the problem wasn't related to how their lungs or heart were functioning. Researchers took multiple blood draws and collected two muscle biopsies from their thighs, a week before they exercised and a day after. Both groups were asked to work out for about 10-15 minutes on a stationary bike, until gradually reaching their maximum aerobic capacity.

The study, based at Vrije and Amsterdam UMC health center, compared 25 people with long COVID to healthy controls who'd fully recovered from COVID-19 and had no persistent symptoms. While symptoms vary, the most common tend to be muscle pain, an increase in fatigue, and cognitive problems, usually referred to as 'brain fog,' that last up to a week after physical exertion. 'For a lot of people, it's completely debilitating for days to weeks.' Most people will get delayed onset muscle soreness after a tough workout, but post-exertional malaise is a different animal altogether. 'We see this at basically every parameter that we measure.'Įxercise tests reveal a cellular energy system gone wrong 'This is a very real disease,' says Charlton. The tissue samples from long COVID patients also revealed severe muscle damage, a disturbed immune response, and a buildup of microclots. 'We saw this immediately and it's very profound,' says Braeden Charlton, one of the study's authors at Vrije University in Amsterdam.

Now research published this month in Nature Communications gives new weightto this assessment.īy taking biopsies from long COVID patients before and after exercising, scientists in the Netherlands constructed a startling picture of widespread abnormalities in muscle tissue that may explain this severe reaction to physical activity.Īmong the most striking findings were clear signs that the cellular power plants, the mitochondria, are compromised and the tissue starved for energy. 'It is very clear that this is not a typical response to exercise.' 'I don't think the messaging has been strong enough,' says David Putrino, the director of rehabilitation innovation for Mount Sinai Health System. The idea that exercise can help patients has proven difficult to shake - despite evidence suggesting this isn't merely a case of deconditioning that patients can overcome by pushing through the pain. These symptoms of exhaustion, or post-exertional malaise as it's called, are a hallmark of long COVID and similar complex illnesses like chronic fatigue syndrome or ME/CFS. That's what many patients with long COVID are told when they talk of the crushing fatigue that envelops them after even a light bout of physical activity.

Discovery go com activate