Exercising for at least 150 minutes every week may improve mobility and quality of life in people with Parkinson's disease, a new study claims.

Parkinson's disease (PD) is a progressive condition that often results in mobility impairments and can lead to decreased health-related quality of life (HRQL) and death.

There is evidence that physical activity can delay decline in PD patients.

Researchers determined that that people who exercised regularly had significantly slower declines in HRQL and mobility over a two-year period.

"We found that people with Parkinson's disease who maintained exercise 150 minutes per week had a smaller decline in quality of life and mobility over two years compared to people who did not exercise or exercised less," said lead investigator Miriam R Rafferty, from Northwestern University in the US.

"The smaller decline was significant for people who started the study as regular exercisers, as well as for people who started to exercise 150 minutes per week after their first study-related visit," said Rafferty.

In the study, more than 3,400 participants provided data over two years, with information collected during at least three clinic visits.

Although this study did not determine which type of exercise is best, it suggests that any type of exercise done with a "dose" of at least 150 minutes per week is better than not exercising.

"People with PD should feel empowered to find the type of exercise they enjoy, even those with more advanced symptoms," said Rafferty.

The study was published in the Journal of Parkinson's Disease.