Just an hour of exercise a day could help slow the progression of life-wrecking Parkinson's symptoms, a study has found.
Playing tennis, jogging and even gardening all delayed the worsening of the condition by up to five years.
More than 160,000 people in the UK are living with the neurodegenerative disease, where nerve cells in the brain stop producing dopamine, causing tremors and stiffness.
Over time patients can lose the ability to move, speak and swallow, and are likely to suffer cognitive decline.
Researchers from the University of Cincinnati followed 294 Parkinson's patients, with an average age of 66, for up to seven years, tracking changes in both movement and cognitive function.
They found those who spent eight or more hours a week being physically active experienced the slowest decline.
Eight hours of exercise a week could help stave off physical and cognitive decline in Parkinson's patients
Activities ranged from vigorous exercise, such as jogging and tennis, to more moderate pursuits including household chores such as vacuuming and gardening.
Overall, the findings suggested that the total amount of activity people did each week was more important than its intensity.
Experts believe exercise may help protect the brain by improving blood flow, strengthening connections between nerve cells and reducing inflammation, all of which could help preserve both physical and mental function.
'Previous research has shown associations between physical activity and movement symptoms,' Dr Dong-Woo Ryu, the study's lead author said.
'Our study found physical activity may have dual benefits, with associations with slower declines in movement and cognition.'
Cognitive function was measured using a standard 30-point test.
Those who were least physically active – exercising for up to just four hours a week – saw their scores fall by around 0.48 points per year.
In comparison, those completing four to eight hours of exercise a week saw declines of 0.009 points a year, while there was virtually no decline among those getting more than eight hours of movement a week.
While the differences may appear modest, Dr Ryu said they could have a meaningful impact on daily life, helping patients live independently for longer.
The study – published in the journal Neurology – found a similar pattern for motor symptoms.
Researchers tracked changes in walking, posture, stiffness and overall mobility using a standard Parkinson's assessment.
Again, those who were the most active experienced the slowest worsening of symptoms.
'The possible benefits of physical activity for people with Parkinson's disease may depend on how long they stay active and whether they continue exercising over time,' Dr Ryu added.
Commenting on the findings, Dr Daniel Truong, a neurologist from the University of California who was not involved in the current study, said exercise remains one of the most important strategies for managing Parkinson's.
He said: 'It has both symptom-relieving and potential disease-modifying effects, especially when started early and performed consistently.'
He advises patients to start small, even ten minutes of movement can be beneficial.
Most patients should start to notice improvements in balance, energy and mood within weeks, he added.
However, the researchers stressed that the study cannot prove cause and effect because it was observational.
It is possible that patients with milder disease and better-preserved cognitive function were simply more able to remain active than those whose symptoms had already progressed.
The researchers are now looking to further studies to confirm whether exercise can genuinely slow disease progression.
The new findings add to a large body of evidence showing that exercise is beneficial for Parkinson's patients.
A 2025 study found that dancing could help stave off cognitive decline, with those who attended a weekly dance class over six years experiencing significantly fewer thinking symptoms.
It comes as a new daily pill for Parkinson's has demonstrated huge benefits in a late-stage trial, raising hopes patients could see the first major new class of treatment in decades.
Current treatments - including medication, physical therapy and surgery - can help manage symptoms, but none has been shown to change the underlying course of the disease.
The new drug, called solengepras, significantly reduced the amount of time patients spent struggling with stiffness, slowness and tremors. It also improved alertness and quality of life, potentially making it easier for patients to stay active.