You may remember those old anti-drug TV ads, that showed a guy cracking an egg into a hot frying pan.  The voiceover simply stated, “This is your brain on drugs.” 

Now we live in an era when drugstores are keeping so-called brain supplements under lock and key because they are wildly popular and equally expensive.  Everyday hundreds of thousands of us download apps promising to “train our brains” and play puzzle games to keep ourselves sharp.  We do all this despite the fact that there is no real evidence that any of those things will help us remember better, think faster, or stave off age-related cognitive decline. 

We’ve known for years about exercise’s positive effects on mood and body.  But it was only recently that scientists have learned that physical exercise is one of the two best ways to strengthen your brain and to significantly combat the cognitive decline that comes with age (the other is getting enough sleep!).  Our brains “on exercise” are faster, more flexible and, in most cases, they’re actually bigger – just like our muscles.  And thanks to new research, we now have a better understanding about why this happens.   

It turns out many of the same mechanisms that allow exercise to improve our moods, also have a powerful effect on our cognition and memory consolidation.   Several new studies show that immediately after a session of physical activity, people perform better on tests of working memory and other executive functions.   

When we get our hearts pumping, it stimulates the release of neurotransmitters like dopamine and serotonin, which account for the mood boosting benefits of exercise.  Exercise also fuels the release of epinephrine and norepinephrine.  Those neurotransmitters make us more alert and motivated, two things essential to absorbing, processing and consolidating information in the short-term. This means that the same system that contributes to that euphoric “runner’s high” feeling also helps us absorb and remember what we’ve learned in the short-term. 

Brain-Boosting BDNF 

BDNF stands for Brain-Derived Neurotrophic Factor. It’s a type of protein in the brain that helps with the growth and maintenance of brain cells. Think of it like a fertilizer for the brain, helping neurons (the cells in your brain) grow, stay healthy, and communicate with each other. When BDNF levels are good, it helps keep the brain functioning well, making it easier to learn new things and remember them.  Exercise increases levels of BDNF, which actually promotes the growth of new neurons in the hippocampus, the part of the brain responsible for memory and learning.   

It starts with the muscles. When we work out, they release molecules that travel through the blood up to the brain and increase our blood flow. Good blood flow is essential to obtain the benefits of physical activity. And conveniently, exercise improves circulation and stimulates the growth of new blood vessels in the brain. 

Neuroplasticity Keeps Our Brains Young 

You may have heard the term “brain plasticity.” It is what makes our brains so extraordinary.  Brain plasticity, also known as neuroplasticity, is the brain’s ability to change and adapt throughout life. It’s like how clay can be shaped and reshaped into different forms. In the brain, this means forming new connections between cells or strengthening existing ones, which can happen as we learn new things, have different experiences, or recover from injuries. 

For example, when you learn to play a new instrument or speak a new language, your brain changes and creates new pathways to store and use that information. Even after an injury, like a stroke, the brain can reorganize itself and form new connections to help regain lost function.  

When we exercise, and produce BDNF, the protein acts like a booster for your brain, helping it to grow new cells and make stronger connections between them. This process is a big part of brain plasticity, which helps your brain to adapt and improve. 

Another substance released into our brains when we exercise is a hormone called irisin (known as “the exercise hormone”).  Irisin has shown such neuroprotective promise that some pharmaceutical companies are working to harness irisin’s effects into drugs to help improve memory and cognitive function, protect against neurodegenerative diseases, or aid in the recovery from brain injuries.  

Can Exercise Really Make Our Brains Bigger? 

Recent research indicates that it can! A greater number of blood vessels and connections between neurons can actually increase the size of different brain areas, including the hippocampus. This effect is especially profound in older adults because it can offset the loss of brain volume that happens with age.  

Our brains (like our height, our muscles and the proteins supporting our skin) shrink with age.  The hippocampus is particularly affected by loss of mass, and that is one reason our memory suffers as we grow older. Recent studies show that exercise can slow, and even prevent, this decline.  

More Established Brain Benefits of Exercise 

In addition to the recent neuroscientific research outlined above, there are other brain boosting benefits of exercise we’ve known about for awhile. 

• Exercise reduces inflammation and inflammation causes the brain and the body to age faster.  This reduction in inflammation can protect brain cells and support cognitive function. 

• Exercise is an antioxidant which helps the brain defend itself against aging and disease. This is important for protecting the brain from damage caused by free radicals, which are unstable molecules that can cause cell damage and contribute to aging and disease. 

• Exercise can help you fall asleep faster and sleep more deeply.  Better sleep can have a positive impact on brain function, as sleep is a critical time for the brain to consolidate memories and repair neuronal damage. 

How Much Exercise Do We Need to Reap All These Brain Benefits? 

The easy answer is that any increase in exercise will help you protect, and even enhance, your brain function.  Cardiovascular exercise is particularly effective.  That means anything that gets your heart pumping, because higher-intensity workouts do appear to confer a bigger benefit for the brain.  Experts suggest that striving for the generally recommended 150 minutes of moderate exercise a week will go a long way towards anti-aging our brains. 

Start Small, Develop a Habit and Save your Brain! 

The most important takeaway is that consistency is key. Studies show that long-term exercise is much more beneficial than a long exercise session.  If you can start by finding a way to add a short burst of activity to every day, you will develop a habit that can preserve your brain function as you age.  It’s pretty terrific that in the meantime, you’ll look better and feel better as well.