CHARLOTTE, N.C. — As millions race to get vaccinated, some say the vaccines aren't only preventing COVID-19, they're also making them feel better.
Several patients who have suffered through 'Long COVID,' a long hauler dealing with symptoms weeks or even months after contracting the virus, are finally feeling like themselves again after receiving COVID-19 vaccines.
Daniel Zaccardelli said he experienced it all himself.
Before the pandemic, he was a healthy cyclist and mountain biker who was always out on a ride.
"I'm pretty in-tune with things going on with my body and was in pretty good shape for the season," he said.
That was until the Zaccardelli, 38, came down with COVID-19 around Christmas.
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"It was a pretty mild case," he said as he remembered having a headache, a fever, and a slight cough.
He thought his battle was over in about seven days but noticed his sense of smell was still gone and rides that were once easy, weren't anymore.
"As soon as I tried to kind of kick it into the extra gear and push myself, that's when I started noticing something was off," Zaccardelli explained.
The data he tracked on an app during rides showed he wasn't performing as usual either.
"Trails I've ridden maybe a hundred times -- I just struggled to get up the hills," he added.
As the weeks and months went on, frustration sank in.
"You know, am I ever going to be able to ride like I used to?" he pondered. "Am I going to have to find another sport?"
However, after receiving his COVID-19 vaccine, Zaccardelli headed down a more promising path.
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"One week after my first dose of the vaccine, I broke one of my personal records that I had since 2016," he said. "To me, that was the sign that I was all the way back."
Dr. Arin Piramzadian with StarMed Healthcare said it's something more and more long haulers are reporting.
"We've seen this in about a third of the people who are getting the vaccines who are considered long haulers," he explained.
Doctors aren't exactly sure why the vaccines are helping some with long COVID, but research is underway.
"If it's fighting the virus, or if it's just making the body reset itself," Piramzadian said. "We don't know why, but if it works, it works."
Another strange development in the fight against a virus that's had so many baffling symptoms and after-effects.
"I would highly recommend getting it," Zaccardelli said. "It helped me out tremendously."
Have a relative or friend in another state and want to know when they can get vaccinated? Visit NBC News' Plan Your Vaccine site to find out about each state's vaccine rollout plan.