Exercise reduces tremors, limb rigidity, slowness of movement and balance, scientists have said.
The study of 128 patients found it prevented the devastating symptoms from worsening for at least six months – and the benefit could last longer.
Participants who indulged in short bursts of hard physical activity were 15 per cent better off than those who remained sedentary – enough to make a difference to their quality of life.
Daniel Corcos, professor of physical therapy and human movement sciences at Northwestern University in Chicago, said: “If you have Parkinson’s disease and you want to delay the progression of your symptoms you should exercise three times a week. It’s that simple.”
Parkinson’s is the second commonest neurological condition – behind Alzheimer’s – and blights the lives of 127,000 people in Britain and more than a million in America.
In the study published in JAMA Neurology, the 40 to 80-year-old participants were assigned to three exercise sessions a week, at either “high intensity”, “moderate” or “not at all”.
After six months they were rated on a Parkinson’s disease scale ranging from 0 to 108 – with the higher the figure, the more severe the symptoms.
Participants in the study had a score of about 20 before exercise.
Those in the “high intensity” group remained with a score of 20.
The group doing “moderate exercise” got worse by one and a half points.
The group that did not exercise at all worsened by three points.