Parkinson’s disease has no cure, but multiple studies have shown that exercise can alleviate symptoms and slow progression.

A recent review published in Cochrane Library — led by Dr. Elke Kalbe, professor of medical psychology at the University of Cologne, Germany — analyzed data for nearly 8,000 people around the world with Parkinson’s. 

Researchers found that those who participated in any type of physical activity showed "mild to large improvements" in motor skills and quality of life compared to those who didn’t exercise.

IS PARKINSON’S DISEASE, 'WORLD’S FASTEST GROWING BRAIN DISEASE,’ MOSTLY PREVENTABLE? STUDY OFFERS CLUES

For Scott Hanley, a 57-year-old native of Belfast, Ireland, the benefits have been life-changing. After two years of what he described as "stumbling in the dark with Parkinson’s," he started a new workout routine. He credits it with completely stopping his symptoms.

When Hanley was first diagnosed, his Parkinson’s was still in the early stages — level 2, with level 5 being the most advanced. But over time, he started to notice more symptoms.

"I had something called dystonia, where multiple parts of my body would go rigid, leaving me incapacitated," he said in an interview with Fox News Digital. 

"I would be walking along, and suddenly my right foot would just lock out or stick to the ground and I would fall over."

Hanley’s doctors put him on medication with plans to review his symptoms every six months. 

"They said I could expect a progression of the disease and that there was precious little we could do about it," he said. "And I found that hugely frustrating."

After a couple of years of struggling with worsening symptoms, Hanley said his mindset shifted. 

"My tolerance for putting up with Parkinson’s had run out," he said. "I decided to try something else."

At the time of his diagnosis, his physical health wasn’t the greatest, Hanley admits.

"I was overweight, I wasn’t active and my diet wasn’t good," he said.

After reading a few success stories, he decided to try CrossFit classes, which incorporate strength and conditioning exercises at a high intensity. 

The workouts focus on building cardiovascular/respiratory endurance, stamina, strength, flexibility, power, coordination, agility, balance and accuracy, according to the CrossFit website. Typical movements include burpees, deadlifts, rowing, squats, medicine ball throws, pull-ups and barbell presses.

For Hanley, the key was that the exercises all had a cognitive element. He had to really think about each movement.

"When we work different parts of the body, they get stronger. So I figured, why not try to make the brain stronger?" Hanley said. "I didn't want to just go for a run or ride a bike — I wanted to challenge my brain pathways with physically intense exercise."

PARKINSON'S DISEASE AFFLICTS THOUSANDS MORE AMERICANS THAN PREVIOUS ESTIMATES: NEW STUDY

Within six months, Hanley said his symptoms had disappeared — even without any medications.

During one period last year, Hanley injured his shoulder and couldn’t work out for four weeks. By the end of that month, he started getting tremors in his hand and his foot began to "stick" again while walking.

After he returned to the gym, the symptoms went away again.

"That’s what really validated the benefits for me," Hanley said.

Blake Bookstaff, an entrepreneur in Knoxville, Tennessee, was diagnosed with Parkinson’s when he was just 47, he told Fox News Digital in an interview.

Some of his early symptoms included a change in gait, involuntary hand movements and "frozen shoulder," which is when the tissues around the shoulder joint become inflamed and make it difficult to lift the arm.

Medications helped lessen the symptoms somewhat, but Bookstaff decided to try ramping up his exercise for greater benefits.

"I saw something on the news about Rock Steady Boxing, which is a franchise that offers workouts for people with Parkinson’s," he said. 

He contacted the owner and scheduled a personal training session — which he now does twice a week.

In the sessions, the trainer focuses on functional movements to help Bookstaff in regular day-to-day activities, such as standing up from a chair or getting in and out of a car. 

"The compound exercises that combine multiple movements have been the most effective for me," he said. "For example, when I’m boxing and I have to think about throwing different types of punches and hitting moving targets, I can actually feel my brain opening up, as if the cobwebs have been lifted."

MICHAEL J. FOX SAYS HE DOESN'T FEEL SORRY FOR HIMSELF BECAUSE OF PARKINSON'S DISEASE: 'NO REGRETS'

During weeks when he doesn’t work out, Bookstaff notices that his body becomes stiffer and harder to move.

Robert D'Egidio, a physical therapist at Atlantic Rehabilitation in Gillette, New Jersey, has seen firsthand how exercise can slow and modify symptoms of Parkinson’s disease. 

"It directly improves ease of movement for activities of daily living, reduces symptoms such as tremor and rigidity, and improves gait features for more normalized stepping and balance," he told Fox News Digital.

Julie Pilitsis, M.D., a neurosurgeon at Marcus Neuroscience Institute in Boca Raton, Florida, agreed with that assessment.

"Exercise is the best thing that people with Parkinson’s can do to take care of themselves," said Pilitsis, who specializes in functional neurosurgery and Parkinson’s disease, in an interview with Fox News Digital. 

"It has some of the most dramatic effects on limiting disease progression. It helps with stiffness, mind-body connection and fitness, just to name a few."

"A good mantra for all of us, but particularly for those with Parkinson’s, is ‘use it or lose it,’" she added.

The Cochrane review found that any type of physical activity — from strength training and endurance to swimming, dance and yoga — can help improve motor skills and quality of life for people with Parkinson’s.

"We observed clinically meaningful improvements in the severity of motor symptoms for most types of exercise," said Dr. Moritz Ernst, first author of the review and a member of Cochrane Haematology, in a press release on the Cochrane website. 

"These included dancing, training to improve gait, balance and movement, multi-exercise training and mind-body training."

Physical therapist D’Egidio recommends doing any aerobic exercise with moderate intensity that will elevate the heart rate 20 to 30 beats above the resting rate for 30 to 40 minutes, three times per week. 

EARLY ALZHEIMER’S DISEASE COULD BE DIAGNOSED THROUGH EYE EXAMS, NEW STUDY SUGGESTS

"We have observed consistently in our clinic that more intensified exercise has a direct impact on disease symptoms," he said. "Exercises should include a variety of functional movements, multidirectional movements and some resistance [strength] training."

For best results, he suggests mixing up the workouts throughout the year.

People with Parkinson’s, however, should pay close attention to any adverse effects and reduce intensity as needed, D'Egidio added.

"Exercise should be discontinued if disproportional pain results from an activity, such as sharp pain in the back, neck, knees and shoulders, or if the person has chest pain or breathing difficulties not consistent with the level of exertion being used," he said.

Neurosurgeon Pilitsis noted that above all, good judgment should come into play. If there are balance issues, for example, high-impact activities may not make sense.

"Sometimes medications or difficulty swallowing can make the patient a bit dehydrated," she said. "If you aren’t feeling well, are going through a period where you are recovering from illness or surgery, are dehydrated, or it is very hot outside, it is better to take it slow and adjust your routine."

Experts agree that it’s always best to get a doctor’s clearance before starting any new exercise program.

While individual exercise may help keep symptoms at bay, having a comprehensive health care team is the optimal way to manage Parkinson's disease over time, E'Egidio believes. 

CLICK HERE TO SIGN UP FOR OUR HEALTH NEWSLETTER

"This includes a movement disorder specialist, primary care provider, neurologist (to assist or support), physical therapist and/or occupational therapist with neurological background, speech therapist (as needed), support groups, community services directed at Parkinson's disease and access to exercise facilities or equipment," he said.

Nearly one million people in the U.S. are living with Parkinson's disease, according to the Parkinson’s Foundation. 

By 2030, it is expected to affect 1.2 million people. Parkinson’s is the second-most common neurodegenerative disease, after Alzheimer's.