Today he stands upright and has ditched the back brace and walker. “My doctors have run strength, balance and gait tests, and everything has improved,” he says. “They decided not to up my medicine. I’m convinced exercise is the reason.”
This would not surprise Parkinson’s experts who point to see you soon and growing body of evidence that supports the positive impact of exercise on the disease. In a new surge of research, scientists are now studying which exercises at what level of intensity provide the greatest gains. The goal is to design an exercise prescription — one that will probably include a mix of high-intensity aerobics and balance, strengthening and stretching exercises — that delay the disease’s onset or, ideally, prevent it altogether. They also want to better understand what exercise does to the brain of a person with Parkinson’s, as well as its effects on nonmotor functions such as mood and cognition. To be sure, exercise can’t cure Parkinson’s — there is no cure — but most researchers believe it can make a positive difference for most patients.
“We have long known exercise is good for Parkinson’s patients,” says Giselle Petzinger, associate professor of neurology at the University of Southern California’s Keck School of Medicine and an early proponent of exercise for Parkinson’s. “What we are trying to do now is further refine what we already know into practical applications for patients.”
Caroline Tanner, a neurology professor at the Weill Institute for Neurosciences at the University of California at San Francisco, predicted in a recent study that new Parkinson’s cases could drop by nearly half by 2030 if all undiagnosed adults regularly pushed themselves to 80 percent of their physical activity capacity. “This could have amazing public health consequences,” Tanner says.
Parkinson’s results from the death of key neurons in the substantia nigra region of the brain that produce the chemical messenger dopamine. Over time, the loss of these nerve cells disrupts movement and diminishes cognition; it can also cause slurred speech and depression. Outward signs can include tremors, muscle rigidity, slowed motion, poor posture and balance, and the inability to perform unconscious actions, for example, blinking, smiling or arm-swinging while walking.
Scientists regard it as a disease of aging, as most patients are older than 60 when diagnosed, although a small percentage occurs among those younger than 50. Nearly 1 million Americans are living with Parkinson’s, and about 60,000 new cases are diagnosed annually, according to the Parkinson’s Foundation. Certain medications and other treatments can ease the symptoms.
Experts, who now regard exercise as chief among those treatments, say it can help at any stage of the disease.
“Typically, when a person starts a new exercise program, the goal is to improve,” says Maria Bellumori, associate professor of kinesiology at California State University at Monterey Bay and clinical director of Power Over Parkinson’s, or POP, the program Sevene attends. “Our goal is also improvement but, at the very least, maintenance. Because Parkinson’s is progressive, if you can maintain physical and cognitive function, that actually is an improvement.”
Ryan Cotton, acting president and CEO of Rock Steady Boxingan international boxing program for people with Parkinson’s, says he has seen the value of intense workouts and quotes several studies in recent years that show the positive impact of boxing. The curriculum is designed specifically for Parkinson’s.
“A boxer who is trying to be defensive would be hunched over, but Parkinson’s itself puts you in that position,” Cotton says. “We want you chin up and tall. Parkinson’s is a lonely disease, and many people don’t go out socially. But when you put on those gloves and start hitting the bag, that apprehension goes away and an ‘I’m kind of a badass’ swagger takes its place.”
He describes the impact on a retired military officer who began boxing six years ago. Dependent on a walker, the man would show up early for classes so he had time to hide the walker before anyone could see it. “He took out all his frustrations on the bag,” Cotton recalls. “Six months later, he was walking independently and later ran a half-marathon. Today someone seeing him on the street wouldn’t even notice he had Parkinson’s.”
Laughing and fighting back
S. Elizabeth Zauber, associate professor of clinical neurology at the Indiana University school of medicine, says the boxing sessions also contribute to a sense of community by creating “a support group that isn’t really a support group.” Zauber, who serves on Rock Steady’s board of directors and its medical advisory committee, says “It’s ‘Hey, let’s laugh at Parkinson’s and fight back.’ … It’s empowering when you see your symptoms improve, and that leads to more confidence.”
Daniel M. Corcos, professor of physical therapy and human movement sciences at Northwestern University Feinberg School of Medicine, is leading a multisite clinical study among those with early Parkinson’s, that is, people diagnosed less than three years ago and who are not yet taking medications, comparing two levels of exercise.
The trial, which is recruiting participants, will study two groups. Members of one group will walk on a treadmill at a speed equal to 60 to 65 percent of their peak heart rate, while the second will work at 80 to 85 percent capacity. Maximal heart rate — the peak rate at which an individual’s heart beats — varies from person to person and is age-dependent. Young people typically have a higher capacity.
Researchers will determine each participant’s peak rate through tests, then calculate that individual’s walking speed for their assigned capacity — either 60 to 65 percent or 80 to 85 percent. The participants will wear heart rate monitors and walk for 30 minutes, four times a week, for two years.
Earlier studies confirmed the safety and feasibility of both routines and suggested anecdotally that the higher-intensity walks produce more benefits.
Jay Alberts, a neuroscientist and vice chair of innovations of the Cleveland Clinic’s Neurological Institute, has been studying the effects of cycling on Parkinson’s for nearly 20 years. His interest began in 2003 during a multiday group bicycle ride across Iowa. After pedaling a tandem bike with a Parkinson’s patient for several days, he noticed a dramatic improvement in her handwriting when she signed a greeting card.
“It was a real ‘aha’ moment,” Alberts says. “It got me thinking that maybe something was changing in the brain.”
Scientists still don’t know exactly what that is but have a few ideas suggesting that there probably are multiple mechanisms at work.
Alberts believes exercise increases neurotrophic factors, small molecules, usually proteins, that promote the growth and survival of brain cells. “They don’t produce dopamine, but they may reduce the effects of whatever is causing the loss of dopamine,” he says.
The higher the exercise intensity, the greater the levels of neurotrophic factors, Alberts adds. However, “while high intensity may be optimal, whatever intensity someone can achieve is better than zero intensity,” he says.
A recent study in mice also found that irisin, a hormone secreted into the blood during endurance exercise, reduces the levels of alpha-synuclein, a protein abundant in the brain that has been linked to the development of Parkinson’s.
Tanner thinks exercise also might help tamp down chronic inflammationwhich occurs when the immune system activates an inflammatory response that never shuts off, often a hallmark of neurologic disorders, she says.
And a recent study Alberts co-authored with Parkinson’s patients, for example, found that high-intensity aerobic exercise improved their information-processing ability.
In the study, 50 Parkinson’s patients engaged in high-intensity cycling on stationary bicycles three times a week for eight weeks. The researchers measured their ability to react to a timed task before starting the exercise program, and then again after it ended. Collectively, the participants showed faster reaction times compared with their earlier performances, indicating that “exercise enhances cognitive function,” Alberts says. Such improvement “could aid in the performance of activities of daily living,” he adds.
POP, the Monterey, Calif., program, includes mental exercises alongside physical ones to keep participants sharp. “While members are hitting the bags, we challenge them cognitively with spelling words, answering questions or doing math problems,” Bellumori says.
Exercise also eases other physical and emotional symptoms that afflict Parkinson’s patients, such as sleep disruption, mood changes and depression, apathy, low energy and constipation, experts say.
The Parkinson’s Foundation already recommend a combination of workouts, and experts say patients shouldn’t wait until scientists come up with research-based specifics to start exercising. “There already is enough excellent evidence to suggest this is a very good thing to do if you are a person with Parkinson’s,” Tanner says.