“All of a sudden, the body’s getting less energy for itself, even though it’s producing the same amount, or even a little more,” he says. And there is a consequence to this extra stress on the cells. “Creating energy isn’t free. You’re producing more waste products, which puts your body in a state of oxidative stress,” Putrino says. Oxidative stress damages cells as molecules interact with oxygen in harmful ways.
“The other big mechanism is autonomic dysfunction,” Putrino says. It’s marked by breathing problems, heart palpitations, and other glitches in areas most healthy people never have to think about. About 70% of long COVID patients at Mount Sinai’s clinic have some degree of autonomic dysfunction, he says.
For a person with autonomic dysfunction, something as basic as changing posture can trigger a storm of cytokines, a chemical messenger that tells the immune system where and how to respond to challenges like an injury or infection.
“Suddenly, you have this on-off switch,” Putrino says. “You go straight to ‘fight or flight,’” with a surge of adrenaline and a spiking heart rate, “then plunge back to ‘rest or digest.’ You go from fired up to so sleepy, you can’t keep your eyes open.”
A patient with viral persistence and one with autonomic dysfunction may have the same negative reaction to exercise, even though the triggers are completely different.
So How Can Doctors Help Long COVID Patients?
The first step, Putrino says, is to understand the difference between long COVID and a long recovery from COVID-19 infection.
Many of the patients in the latter group still have symptoms 4 weeks after their first infection. “At 4 weeks, yeah, they’re still feeling symptoms, but that’s not long COVID,” he says. “That’s just taking a while to get over a viral infection.”
Fitness advice is simple for those people: Take it easy at first, and gradually increase the amount and intensity of aerobic exercise and strength training.
But that advice would be disastrous for someone who meets Putrino’s stricter definition of long COVID: “Three to 4 months out from initial infection, they’re experiencing severe fatigue, exertional symptoms, cognitive symptoms, heart palpitations, shortness of breath,” he says.