Findings from a large study suggest that lower activity levels do not cause Parkinson’s but are an early sign of the disease, raising the possibility of detecting it and intervening years earlier. The study was published in npj Parkinson’s Disease.
Parkinson’s disease is a progressive neurodegenerative disorder that disrupts how the brain coordinates movement, causing tremors, stiffness and balance problems. Rates have more than doubled worldwide since 2000, causing serious disability for millions, according to the World Health Organization.
Since the early 1990s, scientists have been aware of a relationship between physical activity and Parkinson’s. The possibility that exercise could prevent a devastating disease has drawn strong interest from public health officials.
It has always been a ‘chicken and egg situation,’ says Aiden Doherty, Professor of Biomedical Informatics and Wellcome Senior Research Fellow at Oxford Population Health. Does exercise reduce the risk of developing Parkinson’s, or does underlying Parkinson’s reduce activity levels years before diagnosis?
Doherty leads a research group at the Big Data Institute that analyses data from wearable devices to better understand the causes and consequences of disease. To tease apart the relationship between exercise and Parkinson’s, between 2013 and 2015, he and his team gave wearable accelerometers to 100,000 UK Biobank participants aged between 40 and 70 to measure their typical activity levels over seven days.
Exercise not a panacea
More than a decade later, lead author of the study Aidan Acquah, a postdoctoral researcher who works with Doherty at the Big Data Institute, compared the activity profiles of the 407 people in the study who developed Parkinson’s with those of the nearly 95,000 participants who did not.
At first, the data seemed to indicate that exercise protects against Parkinson’s. People who logged more than 10,000 steps per day were about half as likely to be diagnosed with Parkinson’s within the next eight years compared with people who walked fewer than 5,000 steps a day.
Even small boosts in activity seemed to move the needle with each additional 1,000 steps a day corresponding to an 8% lower risk.
But that difference fell apart when the researchers accounted for how far participants were from their eventual diagnosis. Very low step counts were ‘driven by people who are imminently about to be diagnosed with Parkinson’s within a couple years of wearing the step counter,’ Doherty says.
Activity level, then, is a marker of disease already underway rather than a factor shaping risk.
Opportunity for early intervention
This was not the outcome the researchers had hoped for from a public health perspective.
‘Our data do not suggest that exercise will prevent Parkinson’s disease,’ Doherty says. ‘But it does not mean people should stop being physically active. Exercise has many benefits, from cardiovascular to mental health.’
What stands out is that these lower step counts appeared years before diagnosis, during the crucial period when the disease is developing in the brain but clear symptoms have not yet appeared.
This could enable healthcare providers to intervene earlier, when emerging treatments may have a greater chance of slowing progression.
‘They are now trialling various drugs and treatments to look at potential approaches to slow down the progression of the disease,’ Aidan Acquah says.
The rapid uptake of wearable fitness trackers means that similar analyses can now be carried out across much larger and more diverse populations.
The All of Us study, a US programme that aims to enrol 1 million participants, enables volunteers to upload data from their Apple Watches and Fitbits.
‘In five or 10 years, we will be able to do similar analyses in a United States population with a broader range of ethnicities, ages and income levels,’ says Acquah.
A longer version of this article appeared on ScienceNews.dk on 19 April 2026.