A 2-year weight-lifting program improved physical symptoms of Parkinson’s disease – including tremor – and seemed to slow their progression.

The progressive resistance routine, which alternated between increasing strength and speed in weight-lifting, was significantly more effective than was an often-recommended program of strengthening, flexibility, and balance, according to Daniel Corcos, Ph.D., lead author of the comparative study. By the end of the study period, patients who were lifting weights maintained a significant level of improvement, but scores of the other group had fallen back to their baseline levels.

Photo courtesy kali9/iStockphoto.com
While weight lifting obviously benefits a patient by muscular strengthening, there seems to be a neuronal component as well, Dr. Daniel Corcos.

While weight lifting obviously benefits a patient by muscular strengthening, there seems to be a neuronal component as well, Dr. Corcos said in an interview.

“There is no question that part of the changes are related to what goes on in the brain. Every time you make a muscle contract, you involve the motor cortex and basal ganglia,” he said. This repetitive experience appears to alter cortical excitability, improving the connection between brain and muscles, which deteriorates in Parkinson’s, said Dr. Corcos, a kinesiologist and professor of neurologic sciences at the University of Illinois, Chicago.

The investigation randomized 48 people with Parkinson’s disease to the progressive resistance program or to Fitness Counts, a program created by the National Parkinson’s Disease Foundation. Fitness Counts is performed without weights and includes 12 stretching exercises, 7 strengthening exercises, and a set of balancing exercises.

Patients in the weight-training program exercised upper and lower body muscle groups with ever-increasing weight. The initial step determined the heaviest weight a patient could tolerate. Resistance was set at 30%-40% of that maximum weight for the upper body exercises and 50%-60-% of the maximum for the lower body exercises. Weight was increased by at least 5% as soon as the exercise became easier. Every 8 weeks, the program alternated between strength training alone and the combination of strength and speed training, with emphasis on how quickly each repetition could be performed with good form.

The researchers expected each patient to complete 208 sessions by 24 months – usually 2 sessions each week. If they missed a two sessions in a row, the exercise study coordinator contacted the patient. The primary outcome was change on the Unified Parkinson’s Disease Rating Scale III (UPDRS-III) score off medication from baseline to the end of the study.

The patients’ mean age at study entry was 59 years. Most (38) completed the entire 2-year program.

Both the strength training and overall fitness programs had significantly reduced the UPDRS-III score at 6 months (by 6.42 and 5.38 points, respectively). But by the end of 2 years, the weight training group had maintained its improvement (7.3 points), while the fitness group’s score had dropped back to its baseline levels.

The study shows that patients with Parkinson’s can adhere to a sustained exercise regimen and reap valuable benefits from it, Dr. Corcos said. The average Parkinson’s patient experiences about a 30% decrease in normal activity, which provokes muscle deterioration even apart from disease progression. “Think about it. If you, a healthy person, stopped doing anything and laid up in bed for a year, you would still end up in a sorry state,” Dr. Corcos said.

Depression probably contributes to reduced activity along with muscular problems. “Depression is part of Parkinson’s and although not every patient has it, it can be quite disabling. As it becomes harder and harder to move, people lose the motivation [to exercise].”

Patients also tend to put exercise at the bottom of their personal “to do” list, just as many healthy people do.

“As the medications lose effectiveness, patients have fewer periods during which they can get things done,” Dr. Corcos said. “When it’s working well, they have so many things to do that they just don’t find the time for exercise. I hope this objective evidence may motivate patients to realize that exercise should be a top priority.”

His is not the only study expanding the knowledge base in this area.

Fuzhong Li, Ph.D., of the Oregon Research Institute, Eugene, and his colleagues recently published the results of a randomized trial that explored the effect of a modified tai chi program on physical function in Parkinson’s patients. The study randomized 195 patients to tai chi, resistance training, or stretching for 24 weeks. The tai chi group experienced a significantly greater improvement in the UPDRS-III score than did the stretching group (but not the resistance training group), as well as significantly fewer falls than either of the other groups. They retained these benefits at 3 months after the intervention (N. Engl. J. Med. 2012;366:511-9).

Dr. Corcos is scheduled to present the full results of his study in late April at the annual meeting of the America Academy of Neurology.

The National Institutes of Health funded the study. Dr. Corcos had no financial disclosures.