Exercise training and Parkinson's disease: placebo or essential treatment?

Exercise training is often recommended for patients who have Parkinson's disease. Until the debate about the pathophysiologic cause of impaired movement in parkinsonism is settled, it is difficult to develop a specific exercise treatment for symptoms that include hypokinesia, tremor, and muscular rigidity. Most of the published studies show a benefit of exercise training, and we provide an overview of the most essential studies and present conclusions for a practical approach to exercise training in parkinsonism.