Forgot where you put the car keys? Can’t remember what you ate for lunch? Try taking a brisk walk.
A new study adds to a growing consensus that getting too little aerobic exercise negatively affects a person’s long-term memory — that’s anything remembered more than about 30 seconds ago.
The new study, published online in the journal Cognitive, Affective, & Behavioral Neuroscience, is among the first to investigate the memory level in young, healthy adults.
The findings speak to the increasingly sedentary lifestyles found in the United States and other Western cultures, said Kimberly Fenn, study co-author and Michigan State University assistant professor of psychology.
Researchers tested 75 college students during a two-day period and found that those who were less fit had a harder time retaining information.
“The findings show that lower-fit individuals lose more memory across time,” said Fenn.
“A surprising number of the college students in the study were significantly out of shape and did much worse at retaining information than those who were extremely fit.”
Converging evidence across human and animal studies suggests that high-level cognitive systems, such as memory, may be sensitive to levels of aerobic fitness and physical activity, according to the study.
Previous research on fitness and memory has focused largely on children, whose brains are still developing, and the elderly, whose memories are in decline. In each case, the poorer the aerobic fitness level, the lower the memory performance.
A six-month Canadian study looking at women with early memory problems found that aerobic activity increased the size of the hippocampus, an area of the brain involved in learning and memory. The women in this study were between 70 and 80 years old, living independently at home and at risk of dementia.
The hippocampus shrinks as part of normal aging. Previous research found this shrinkage speeds up as we grow older, foreshadowing memory problems and dementias like Alzheimer's disease.