Editor’s note: Ask your doctor for advice before starting an exercise program.
What if you could look at all the things you do every day—walking from room to room, preparing a presentation at your desk, running up and down the stairs to fetch a load of laundry, or running around the block—and know which ones will best help or hurt your brain?
A new study attempted to answer that question by attaching activity monitors to the thighs of nearly 4,500 people in the UK and tracking their movements 24 hours a day for seven days. The researchers then examined how the participants’ behavior affected their short-term memory, problem-solving and processing skills.
Here’s the good news: People who spent “even small amounts of time in vigorous activity — as little as 6 to 9 minutes — compared to sitting, sleeping, or gentle activity had better cognitive outcomes,” said study author John Mitchell, Medical Research Student PhD from the Institute of Sport, Exercise and Health at University College London, in an email.
Moderate physical activity is usually defined as brisk walking or cycling or running up and down stairs. Vigorous movement, such as aerobics, running, jogging, swimming and uphill cycling, will get your heart rate and breathing up.
Study, published Monday in the Journal of Epidemiology & Community Healthfound that just under 10 minutes of moderate-to-vigorous exercise each day improved study participants’ working memory, but had the greatest impact on executive processes such as planning and organization.
The cognitive improvement was modest, but as more time was spent on more vigorous exercise, the benefits grew, Mitchell said.
“Because we don’t track participants’ cognition over many years, this may simply be that those individuals who move more tend to have higher cognition on average,” he said. “However, yes, it can also mean that even minimal changes in our daily lives can have downstream consequences for our cognition.”
Steven Malin, an associate professor in the Department of Kinesiology and Health at Rutgers University in New Jersey, told CNN that the study provides new insight into the interaction of activity with sedentary behavior as well as sleep.
“Understanding the interaction between sleep and various physical activities is often not examined,” said Malin, who was not involved in the new study.
Although the study had some limitations, including a lack of knowledge about the participants’ health, the results show that “accumulating movement patterns over a day, week, or month is just as important, if not more, than just getting outside for a single exercise session,” he said.
There was also some bad news: spending more time sleeping, sitting, or engaging in only mild movement has been linked to a negative impact on the brain. The study found that cognition decreased by 1% to 2% after replacing an equivalent portion of moderate-to-vigorous physical activity with eight minutes of sedentary behavior, six minutes of light intensity, or seven minutes of sleep.
“In most cases, we showed that just 7 to 10 minutes less MVPA (moderate to vigorous physical activity) was harmful,” Mitchell said.
That change is only an association, not cause and effect, because of the study’s observational methods, Mitchell emphasized.
In addition, the sleep study findings cannot be taken for granted, he said. Quality sleep is essential for the brain to function at its peak.
“The evidence for the importance of sleep for cognitive performance is strong,” Mitchell said, “however there are two main caveats. First, excessive sleep may be associated with poorer cognitive performance.
“Secondly, the quality of sleep may be even more important than the duration. Our accelerometers can estimate how long people slept, but they can’t tell us how well they slept.”
Additional studies are needed to confirm these findings and understand the role of each type of activity. However, Mitchell said, the study “highlights how even very modest differences in people’s daily movement — less than 10 minutes — are associated with quite real changes in our cognitive health.”