You know that great feeling you get after a brisk walk or bike ride? It turns out that your brain is reaping the rewards as well. You see, your heart-pumping workout is sending extra blood throughout your body and bathing your cells—including your brain cells—in oxygen and glucose, which they need to function.
So it’s no surprise that scientists have recently collected plenty of evidence linking exercise to memory improvement. Even more exciting, exercise sharpens the memory not only in those who are cognitively healthy, but also in those who are already suffering from memory loss.
Scientists at the University of Texas Southwestern Medical Center took a deep dive into how exercise affects brain health. Specifically, they were investigating what happens during exercise to trigger any benefits to memory.
In one study, the UT Southwestern team found evidence that aerobic exercise improved cardio-respiratory fitness and increased blood flow to the brain, as well as memory function, in people with mild cognitive impairment (MCI), a precursor to Alzheimer’s disease.
Boost Blood Flow and Boost Memory
While previous studies have documented the benefits of exercise for cognitively normal adults, these researchers looked at folks who were at high risk of developing Alzheimer’s disease.
Last year researchers began this investigation into changes in cerebral blood flow and memory health in 30 participants, aged 60 years or older, who were already suffering from memory problems. Half of the group was assigned to 12 months of aerobic exercise. The rest only performed stretching exercises.1
Scientists discovered that the aerobic exercise group showed a significant 47 percent improvement in memory scores by the end of the study. As for the group who performed stretching exercises? They experienced minimal change in memory function.
What’s more, scientists conducted brain-imaging tests at the beginning and again at the end of the study, which revealed further insights. The imaging tests showed that the exercise group experienced increased blood flow in the anterior cingulate cortex and the hippocampus– two regions of the brain which play critical roles in memory function.
“Cerebral blood flow is a part of the puzzle, and we need to continue piecing it together,” says Dr. Binu Thomas, Ph.D., a UT Southwestern senior research scientist. “But we’ve seen enough data to know that starting a fitness program can have lifelong benefits for our brains as well as our hearts.”
He adds that the study is critical because it shows that even as memory starts to fade, you can make a difference by adding aerobic exercise to your health regimen.
Dr. Thomas’s study was first published in the Journal of Alzheimer’s Disease.
Huffing and Puffing Your Way to Cognitive Health
Another study, also from UT Southwestern, was published in the Journal of Applied Physiology this year.2 Similar to the 2020 study, researchers observed 37 people with mild cognitive impairment, ages 55 to 80, for 12 months.
During the first ten weeks, participants performed three exercise sessions each week that included brisk walking for 25 to 30 minutes. But by week 11, researchers increased their exercise sessions to four times a week, requesting that participants walk briskly uphill for 30 to 35 minutes per session. By week 26, they were exercising up to four or five times a week for 30 to 40 minutes each session.
Scientists found that vigorous exercise was linked to a host of benefits for folks with mild cognitive impairment. These exercisers not only improved their cerebral blood flow regulation and cardiorespiratory fitness, but also their memory and executive function.
Dr. Tsubasa Tomoto, Ph.D., the paper’s lead author, says the team is focused on mild cognitive dysfunction for a good reason.
“There is some research that suggests that if you do intervention, you could have some hope in reducing Alzheimer’s,” Dr. Tomoto explains. “If you could exercise, it could improve vascular function and may lead to cognitive improvement.”
Dr. Santosh Kesari, Ph.D., a director of neuro-oncology at Providence Saint John’s Health Center in California, weighed in on the study.3
In his view, “It validates the fact that exercise can improve cardiovascular and brain function in a fairly short period of time.”
Your Brain Needs Fuel
There’s an important reason why researchers keep looking at the link between exercise and Alzheimer’s disease. According to Benjamin Bikman, Ph.D., an associate professor at Brigham Young University, the hungry brain needs an enormous amount of fuel (glucose).
“In order for the brain to get all the energy it needs, the hormone insulin must be able to do its job,” Dr. Bikman says. “Insulin, among many roles, opens glucose doors into parts of the brain involved in memory and learning, helping those brain cells get all the glucose they need to function.”
I am a strong advocate of exercise—especially walking— because of its benefits to your memory and overall physical and emotional health. Best of all, you don’t need a gym membership to walk, you can do it just about anywhere, free of charge.
However, I believe that exercise is just another arrow in your quiver and should be included as part of a healthy lifestyle. For example, diet and supplementation, regular sleep, managing physical and emotional stress, socializing with others as well as engaging your brain in cognitive activities such as crossword puzzles, studying a new language, or taking up a new hobby are also vitally important to sharpening your memory.
In the end, it’s wise to take a multi-pronged approach to brain health if you want to lower your risk of developing dementia and Alzheimer’s disease.