Scientists Just Discovered That Exercising for 12 Weeks Can Improve Your Brain Function

Reviewed by Dietitian Katey Davidson, M.Sc.FN, RD, CPT

Key Points

• Regular exercise has been linked to a healthier brain.
• Exercise influences BDNF production, a brain protein essential for healthy cognition.
• Exercise-induced BDNF may help your frontal cortex perform better.

You probably already know that exercise strengthens your heart and muscles, but did you know it also strengthens your brain? And the benefits are not limited to just one type of exercise. Whether you prefer hitting the weights, going for more meditative workouts like yoga and tai chi or getting in a quick bout of cardio, your brain is thanking you by improving your mood, whisking away the brain fog and lowering your risk of dementia.

But because scientists also care about the how and why behind the what (results), researchers from the United Kingdom decided to take a closer look at a special protein called brain-derived neurotrophic factor (BDNF). BDNF acts like fertilizer for the brain and plays a role in neuroplasticity, the ability of the brain to form new neural connections. They already knew that exercise had been shown to increase levels of BDNF (a good thing!) and that exercise also improved certain aspects of brain health, like memory and focus.

But they weren’t sure whether exercise-induced BDNF production directly supports specific areas of the brain during cognitive function and memory tests. They also didn’t know if BDNF samples provide different insights into this relationship.

Unlike many studies that examine BDNF from one angle, these researchers examined the presence of BDNF using two different laboratory preparations: plasma BDNF (pBDNF) and serum BDNF (sBDNF). The results of this study were published in Brain Research. Let’s break down what they found.

How Was This Study Conducted?

The 23 participants, seven of them female, were between the ages of 18 and 55 and were classified as being sedentary, meaning they had engaged in less than 30 minutes of moderate-intensity exercise for fewer than three days per week for the past three months. They were screened using the Physical Activity Readiness Questionnaire (PAR-Q) and excluded if any contraindications to exercise came up.

Participants were randomly assigned to one of two groups: an intervention group and a control group. The intervention group completed a 12-week cycling exercise program of varying intensities that were predetermined for them.

All participants attended three laboratory visits during weeks zero (baseline), six and 12, at which time they had bloodwork and body composition measurements taken. At each lab visit, participants also completed a VO2max test, which tests maximal exercise performance.

They also completed a battery of executive function and episodic memory tasks before and after each VO2max test. Executive function is an umbrella term used to describe the mental skills and cognitive processes managed by the prefrontal cortex (the front part of the brain). In addition, all participants were instructed to refrain from starting a new diet during the study period.

What Did This Study Find?

While all the results did not align with some of the scientists’ hypotheses regarding resting-state BDNF concentrations and cognitive performance, they did find enhanced production of sBDNF in response to acute maximal exercise at 12 weeks, after improvements in cardiopulmonary fitness.

This increase in exercise-induced sBDNF, as well as circulating pBDNF levels, was associated with changes in prefrontal cortex activity during executive function tasks. According to these researchers, these results suggest a potential role for BDNF in modulating brain function in response to improvements in physical fitness—the “why” behind the link between physical activity, BDNF production and brain function.

This study was very small as far as studies go, which means that the results must be interpreted with caution. The more participants a study uses, the more likely the results are to be accurate. Researchers also point out that hormonal differences between male and female participants may influence BDNF levels, and this aspect was not measured or considered in this study. Lastly, researchers point out that while most studies draw blood immediately after exercise, there was a latent period of about 30 minutes to allow time for cooldown, brain imaging setup and cognitive testing. And while previous research suggests that BDNF stays in the blood for about 30 minutes following exercise, they feel the latent time should be considered a possible limitation of this study.

How Does This Apply to Real Life?

Your brain is your body’s control tower. From it come thoughts, and from thoughts, emotions and behaviors. Depression and anxiety live in the brain, and Alzheimer’s disease and other neurological diseases begin in the brain. Many of the changes in the brain that lead to brain diseases begin years, sometimes decades, before symptoms show up. So now is the time to start taking care of your brain.

We know that a sedentary lifestyle can accelerate brain aging and increase your risk of brain-related diseases, like dementia. So an easy solution would be to move your body—and brain—more often. Besides increasing BDNF, movement also improves blood flow to the brain. More blood flow means more nutrients and oxygen are being delivered, two things essential to brain health. This also means that you may be able to slow the speed at which your brain is aging and clear out the cobwebs that can accumulate and lead to symptoms like brain fog.

If you’re not currently a regular exerciser, a great way to increase your physical activity is by simply getting up more often throughout the day to move your body. Take movement breaks every 30 to 60 minutes to stand up, walk around, do a set of stairs or perform push-ups against a wall or your desk. If you stay well-hydrated, it’ll be a good reason to get up to use the bathroom—do some walking lunges on your way there. And avoid using the excuse that taking breaks will disrupt your productivity. There is evidence that taking breaks actually increases productivity and reduces fatigue.

If you’re already in the exercise groove, the take-a-break principle applies to you, too. Also, consider the types and intensities of exercise you’re engaging in. Are you doing only cardio? Add some strength training and stretching. You can integrate cardio into a strength training workout by doing a circuit and reducing the time between sets. Plus, many people will benefit from mind-body workouts like yoga. Hatha yoga, which is a type of yoga that takes you through a series of asanas or poses, is a great strengthening type of yoga that can also get your heart rate up. It, too, has been shown to increase BDNF for a healthier brain.

No matter where you are on the exercise spectrum, start where you’re at and gradually work up from there until you reach a level you’re comfortable with and can sustain over the long haul. And remember, any amount of movement is better than no movement at all.

Other brain-healthy habits include eating a varied, balanced diet, lowering your stress levels and getting plenty of healthy sleep. If figuring out what to eat is confusing for you, following a meal plan for brain health can help make things clearer. Check out our 30-Day MIND Diet Meal Plan for Cognitive Health. It combines the principles of the Mediterranean and DASH diets with lower-sodium, minimally processed foods that are packed with vitamins, minerals, lean proteins, fiber, healthy fats and antioxidants—everything your brain loves.

Our Expert Take

This study suggests that bouts of maximal-intensity exercise combined with improved cardiovascular fitness can trigger greater brain-derived neurotrophic factor (BDNF) production in the brain. Researchers observed that the increased level of BDNF resulted in better cognitive performance after exercise. But you don’t have to work out to exhaustion to see brain-healthy results.

Other studies have shown benefits to brain health by moving more often and engaging in various forms of exercise—including cardio, strength training and mind-body exercise. Make an intentional decision to move more often throughout your day. And if you’re already a regular mover and shaker, mix your workouts up so that you’re getting more well-rounded results—for your brain, heart, muscles and bones.

Read the original article on EatingWell