A high level of regular physical activity may help delay the onset of motor symptoms associated with Parkinson’s disease, say Swedish researchers.

Long-distance skiers were almost 30% less likely to develop Parkinson’s than non-skiers in the first years of a 21-year study, investigators found. But this payoff doesn’t last forever. By year 15, the odds were similar for both groups, reported Tomas Deierborg, Ph.D., and colleagues from Lund University.

Even so, this “motor reserve” appears to ensure more years of function for highly physically active older adults, the researchers wrote. The effect may be similar to that of cognitive reserve, they theorized. In this well-documented phenomenon, highly educated adults with varied life experiences have no outward signs of dementia – despite the presence of brain atrophy on a scan.

People who have motor reserve would likewise experience a delay in developing measurable symptoms such as tremor and rigidity, despite having brain changes associated with Parkinson’s.

“[The results] highlight the importance of staying physically active throughout life in order to have a reserve to better cope when the frailties and diseases of old age inevitably arrive,” concluded Deierborg.

Full findings were published in the Journal of Parkinson’s Disease.