The study shows that simple changes to physical activities - such as walking, taking the stairs or even frolicking on the beach - can result in better memory for older adults.
The study, which is published in the Journal of the International Neuropsychological Society, could have implications for the fight against memory decline brought on by aging and neurodegenerative dementias, such as Alzheimer's disease.
Scott Hayes, PhD, from Boston University School of Medicine, MA, and associate director of the Neuroimaging Research for Veterans Center, led the study.
He and his colleagues note that until now, few studies have objectively examined physical activity in both young and older adults, and investigated whether physical activity is associated with cognition in aging.
To conduct their study, the researchers had 29 young adults between the ages of 18-31 and 31 older adults between the ages of 55-82 wear an ActiGraph - a small device that records information on how many steps are taken, how vigorous the steps are and how much time is involved.
Rather than using self-reported questionnaires - which previous studies have utilized and can be impacted by memory failures or biases - the current study used this objective measure of physical activity, which the researchers say is a key component.
'Lack of physical activity may negatively impact memory abilities'
The participants also underwent neuropsychological testing so the researchers could assess their memory, planning and problem-solving skills. After these tests, the participants took part in a laboratory task that involved learning face-name associations.
Overall, the older adults who took more steps each day performed better on the memory tests than their more sedentary counterparts, the researchers observed.
Furthermore, the link between number of steps taken and memory was strongest with a task that involved matching a person's face with their name, which is the same type of information that older adults typically have a problem recalling.
The researchers say these types of tasks are likely more difficult for older individuals because they make strong demands on the hippocampus.
Interestingly, the team says that the association between number of steps and memory performance was not observed in young adults.
Commenting on their findings, Hayes says:
"Our findings that physical activity is positively associated with memory is appealing for a variety of reasons. Everyone knows that physical activity is a critical component to ward off obesity and cardiovascular-related disease. Knowing that a lack of physical activity may negatively impact one's memory abilities will be an additional piece of information to motivate folks to stay more active."
Given that aging is linked with reductions in executive and episodic memory, these findings show promise for those who hope to maintain memory performance as they age.
In the US, 1 in 3 seniors die with Alzheimer's or another dementia, and Alzheimer's is the sixth leading cause of death in the country. Staying physically active to preserve memory function can take on a variety of forms, say the researchers.
From formal exercise programs to simply walking or taking the stairs, Hayes notes that even simple changes can make a difference.
He adds that more research is needed "to explore the specific mechanisms of how physical activity may positively impact brain structure and function." The researchers would like also to clarify how specific exercise programs impact on cognitive function.
Medical News Today recently reported on a study that showed how daytime naps and rewards help to cement memory.