After six months, the researchers found, there was no clear benefit for the study group as a whole. The picture looked different, however, when they focused on the 122 patients with milder Parkinson's symptoms.
Among those patients, 52 percent of exercisers had a fall over six months. That compared with 76 percent of those who did not exercise.
"This large effect was achieved with only 13 percent of exercise sessions supervised by a physical therapist," Canning said. "The results of our study suggest that early intervention for people with Parkinson's disease should be extended to include minimally supervised balance and strengthening exercises as a falls-prevention strategy."
"Early" is the key word, according to Canning. "We should not be waiting until the person has already fallen," she said.
Only an association was found between exercise and risk of falling among Parkinson's patients; the study did not prove cause and effect.