In the study, 29 young adults (ages 18-31) and 31 older adults (ages 55-82) wore a small device called an ActiGraph, which recorded information including how many steps each took, how vigorous the steps were and how much time it involved. Participants also completed neuropsychological testing to assess their memory, planning and problem-solving abilities.

Researchers at Boston University Medical Centre found that older adults who took more steps per day had better memory performance. The researchers said that these findings demonstrated that the effects of physical activity extend to long-term memory--the same type of memory that is negatively impacted by aging and neurodegenerative dementias such as Alzheimer's disease.

Author Scott Hayes of the Boston University Medical Centre said that their findings that physical activity was positively associated with memory was appealing for a variety of reasons, adding that everyone knew that physical activity was a critical component to ward off obesity and cardiovascular-related disease. Hayes said that knowing that a lack of physical activity might negatively impact one's memory abilities would be an additional piece of information to motivate folks to stay more active. The authors point out that staying physically active can take a variety of forms from formal exercise programmes to small changes, such as walking or taking the stairs.

The study is published in the Journal of the International Neuropsychological Society.