SAN DIEGO -- A gym in North Park is helping people with Parkinson's battle the disease ... literally.
Boxfit in North Park hosts two, 90-minute boxing classes fighting something you can't see in a ring.
"The only thing that slows the progression of Parkinson's is forced, intense exercise," Mike Reed, the gym's founder, explained. "And that's what we do here."
Parkinson's is a progressive degenerative neurological disease.
"You've seen it from the extreme to the mild. You know what's coming ... so you prepare for the fight," Sara Principato, aka "Lightning," told FOX 5. "That's what I'm doing. That's how I feel when I come. I'm preparing for the fight."
Principato has been battling Parkinson's for six years. At Boxfit she's not alone in the "Rock Steady Program."
"One of the biggest benefits for me is the camaraderie. It's nice being around other people with Parkinson's," Dr. Gerald Spector, aka "Dr. Steel Hammer," said. "It's just a very very pleasant group of people. We are all in the same boat together."
It's estimated that between 1 and 1.5 million people in the US have Parkinson's disease, including 60,000 in San Diego county. Boxing helps slow down the progression of the disease -- and these fighters have absolutely no plans of slowing down.
"Any time someone comes into the gym, I tell them, 'You're not just a person with Parkinson's. You're a Parkinson's fighter.' So as a result, they need to have a boxing name. If they can't think of one, I'll bestow one upon them by the end of their first class," Reeder explained.
When people think of Parkinson's and boxing, they often remember that Muhammad Ali fought the disease. It's a common misconception that boxing led to his development of Parkinson's, when in fact it helped him slow its progression.
"It gives you strength and it allows you to carry that into all the aspects of your life. You just feel stronger. And you feel like you can take on the world. There's nothing that you can't do," Principato said.
The Rock Steady Program costs $100 each month for unlimited classes.
"Lightning" encourages anyone looking to get active to come by: "Do it. Just do it. You can't be a couch potato. Life is too short and too precious. You have to fight."