Exercise and our Brain Scientists Continue to Learn More

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This article was edited and updated on December 12, 2021.

We must use our memory to keep it

Just like muscular strength, your ability to remember increases when you exercise your memory and nurture it with a good diet and other healthy habits. Memory, like muscular strength, is a “use it or lose it” proposition. The more you work your brain, the better you’ll be able to process and remember information.

With short-term memory, your mind stores information only for a few seconds or minutes: the time it takes you to dial a phone number you just looked up. Such memory is fragile, and it’s meant to be; as well, your brain only holds an average of seven items at a time.

Long-term memory involves:

Some long-term memory requires a conscious effort to recall it:

There is also a procedural memory which involves skills and routines you perform so often that they don’t require conscious recall.

Exercising your Brain and your Memory

Brain exercise (called neurobic exercise) involves novelty and sensory stimulation. It forces you to use your faculties in unusual ways, and it’s the most effective way to keep your synapses firing. Some examples:

Treating your body well can enhance your ability to process and recall information. The key to exercising your brain is choosing to do something new and different — to challenge your brain.

Staying Healthy Helps your Brain

Here are four ways to stay healthy:

Several factors cause aging brains to experience changes in the ability to retain and retrieve memories. However, in healthy older adults, these changes represent more of a slowing in the ability to absorb, store, and retrieve new information, not a loss. The factual information you’ve accumulated over the years remains largely intact, as does procedural memory. You can make and recall new long-term memories; the process just takes a little longer.2

CBC's Quirks and Quarks Talks about Exercise and the Aging Brain

In 2011, the CBC radio program, “Quirks and Quarks,” did a twenty-minute segment on their hour-long weekly program titled “Exercise and the Aging Brain.”3

The program began by telling us that “evidence has been accumulating for a decade now that the best way to forestall or even reverse age-related mental decline is with a regular program of exercise.” Most of us know (though we don’t like to admit) that a certain amount of mental decline is a normal part of the aging process, along with losing muscle tissue, joint flexibility, and bone density. But, the scientists tell us something else we may not have known: we also lose brain volume as we age!

The good news here is that “studies have shown consistently that people who exercise regularly can resist this decline.” Yes, that is indeed very good news, especially on this website which is all about the benefits of exercise.

Who's talking and what are they saying?

Neuroscientists are Learning Amazing Things about our Brains

“Neuroscience is beginning to touch on questions that were once only in the domain of philosophers and psychologists, questions about how people make decisions and the degree to which those decisions are truly ‘free.’ These are not idle questions. Ultimately, they will shape the future of legal theory and create a more biologically informed jurisprudence.”4

Neuroscientists are more certain, with each day of research completed, that much of our behaviour is connected to our brains. Do you remember the young man, Charles Whitman, who in early August 1966, rode the elevator to the top floor of the University of Texas Tower in Austin, Texas, and then began shooting at people? In the end, he killed 13 people and wounded 32 more. He was killed by police as they stormed the tower.

The obvious question we all ask when things like this happen is: Why?

Before Charles Whitman did that terrible act, he wrote a note which said, in part: “I don’t really understand myself these days. I am supposed to be an average reasonable and intelligent young man. However, lately (I can’t recall when it started) I have been a victim of many unusual and irrational thoughts.”

Whitman asked that his brain be studied after his death. He said that he had sought medical advice prior to his rampage at the top of the Texas Tower because he “tried to convey...[his] fears that [he] felt [overcome by] overwhelming violent impulses.” The doctor, he said in his note, didn’t help him at all.

Curious scientists did as he asked and looked at his brain after his death. “[They] discovered that [his] brain harboured a tumour the diameter of a nickel. This tumour, called a glioblastoma, had blossomed from beneath a structure called the thalamus, impinged on the hypothalamus, and compressed a third region called the amygdala.”

We have known for some time that the amygdala regulates fear and aggression. “By the late 1800s, researchers...discovered that damage to the amygdala cause[s] emotional and social disturbances.” As well, we know from studies done in the 1930’s that damage to the amygdala can cause a lack of fear, the blunting of emotion, and a general overreaction to all stimuli.

David Eagleman concludes: “Whitman’s intuition about himself—that something in his brain was changing his behaviour—was spot-on.”

How often are we behaving in a certain way because of what is happening in our brain?

More often than you think.

He points out that “changes in the balance of brain chemistry, even small ones, can also cause large and unexpected changes in behaviour.”

Eagleman uses the victims of Parkinson’s disease as an example of this: “In 2001, families and caretakers of Parkinson’s patients began to notice something strange. When patients were given a drug called pramipexole, some of them turned into gamblers. And not just casual gamblers, but pathological gamblers. These were people who had never gambled much before, and now they were flying off to Vegas. One 68-year-old man amassed losses of more than $200,000 in six months at a series of casinos. Some patients became consumed with Internet poker, racking up unpayable credit-card bills. For several, the new addiction reached beyond gambling, to compulsive eating, excessive alcohol consumption, and hypersexuality.”

“What was going on?” Eagleman asks. “Parkinson’s involves the loss of brain cells that produce a neurotransmitter known as dopamine. Pramipexole works by impersonating dopamine. But it turns out that dopamine is a chemical doing double duty in the brain. Along with its role in motor commands, it also mediates the reward systems, guiding a person toward food, drink, mates, and other things useful for survival. Because of dopamine’s role in weighing the costs and benefits of decisions, imbalances in its levels can trigger gambling, overeating, and drug addiction—behaviours that result from a reward system gone awry. Physicians now watch for these behavioural changes as a possible side effect of drugs like pramipexole. Luckily, the negative effects of the drug are reversible—the physician simply lowers the dosage, and the compulsive gambling goes away.”

What has this to do with fitness and exercise?

Perhaps not a lot, and perhaps more than we even know yet. Human behaviour is complex and also fascinating to study.

Eagleman concludes the obvious for us:

“The lesson from...these stories is the same: human behaviour cannot be separated from human biology. If we like to believe that people make free choices about their behaviour (as in, “I don’t gamble, because I’m strong-willed”), cases like [Charles Whitman and]... the gambling Parkinson’s patients may encourage us to examine our views more carefully. Perhaps not everyone is equally ‘free’ to make socially appropriate choices.”

If much of our behaviour is controlled by the brain, then maybe we will some day know why some people exercise and others don’t...or why some people gain weight and others don’t. It may not be the answer to ALL our questions, but it certainly will assist in helping us to understand human behaviour.

Eagleman says this: “Many of us like to believe that all adults possess the same capacity to make sound choices. It’s a charitable idea, but demonstrably wrong. People’s brains are vastly different.” So, as simple an idea as it is, perhaps this is why some people smoke, drink to excess, and engage in reckless behaviour, while others go to fitness class, try to take care of their health, and (maybe) live longer.

Recommended reading: The Believing Brain: How we Construct Beliefs and Reinforce them as Truths by Michael Shermer.

This article is part of a series about various health conditions and the benefits of exercise. The other articles are:

I am a BCRPA-certified fitness instructor in Vancouver, BC. I teach four classes at the West End Community Centre in Vancouver, BC, mostly designed for the older adult. The Inevitable Disclaimer: Everything published here expresses only my opinion, based on my training and research. What you do with the information is entirely your own responsibility. I am not liable for any injury you suffer that seems to be related to anything you read here. Always consult your doctor before beginning an exercise program. For other articles, return to the table of contents.

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  1. These three dots behave exactly like a footnote. Click on them and you will get more information about the topic. ↩︎

  2. For more good ideas about keeping your memory, check this article written by Ellen Jaffe–Gill, M.A., Amara Rose, Gina Kemp, M.A., and Suzanne Barston. ↩︎

  3. The program was broadcast on April 2, 2011, and used to be available on a podcast at the CBC Quirks and Quarks website as well as in iTunes. If it's still there, you will find it titled “Exercise and the Aging Brain”. ↩︎

  4. These are the last words of David Eagleman in his article, “The Brain on Trial” in the July/August 2011 edition of The Atlantic↩︎