For the study, 167 people average age 80 wore movement monitors on their wrists for 11 days to measure exercise and non-exercise activity. Tests of movement abilities were also taken each day, and MRI scans were used to determine the volume of white matter hyperintensities in the brain.
- Those in the top 10 percent had activity equal to walking at 2.5 mph for an additional 1.5 hours each day, compared to those at the 50th percent in activity level measured using the movement monitors
- For the people in the top 10 percent, having greater amounts of brain damage did not change their scores on the movement tests, but for those at the 50th percent activity level, having greater amounts of brain damage was associated with significantly lower scores on the movement tests.
- For all the participants, the average score on the movement tests was 1.04.
- For people at the 50th percent activity level, scores ranged from 1.16 for those with the lowest amount of brain damage to 0.9 for those with the highest amount of brain damage. The detrimental effect was even stronger for those with the lowest levels of physical activity.
The study does not determine whether physical activity causes people to preserve their movement abilities but only shows the association. These results underscore the importance of efforts to encourage a more active lifestyle in older people to prevent movement problems, which is a major public health challenge, says study author Debra A. Fleischman, PhD of Chicagos Rush University Medical Center. Physical activity may create a reserve that protects motor abilities against the effects of age-related brain damage.