Some answers are coming in on long Covid disease

As seen in other long COVID studies, the problem wasn't related to how their lungs or heart were functioning. Instead, something was making it hard for the muscle to take up the oxygen in the blood.

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"As opposed to what's been sold to patients over the last few decades, that symptoms such as extreme fatigue and exertional malaise are psychological or physical conditioning issues," he says. "Physical exertion does harm to the bodies of people with these illnesses."

His general guidance is to avoid exercise if you have post-exertional malaise and instead practice "energy conservation."

At his clinic, Putrino prescribes what's called "autonomic rehabilitation" for these patients.

  NPR