Lately I've been reading up on brain health, and I want to share some of the most significant findings with you, especially as it pertains to keeping your brain healthy, strong, and sharp throughout your life.
It's estimated that a human brain consists of about 100 billion neurons. Collectively they give you a tremendous amount of mental processing power, but since these are biological cells, they don't last forever, and their performance depends on many factors. Anyone who's ever had a little too much alcohol can attest to the fact that physical substances can affect how you think.
Fortunately your brain is very resilient, and no single cell is critical to its functioning. But when enough of these cells suffer damage or degradation, temporarily or permanently, you suffer for it physically, mentally, or emotionally. You may have a harder time expressing yourself, solving problems, doing creative work, or remembering information if your brain isn't working optimally.
As you get older, it's common to experience a significant amount of neuron death. Your brain cells eventually begin dying off in larger numbers.
If this cell death occurs in one region of the brain, you may be diagnosed with Parkinson's disease and have problems with tremors and loss of motor control and coordination. If it happens in a different area, you'd be afflicted with Alzheimer's. In another part of the brain, you'll experience some other form of dementia.
As the baby boomer population ages, mental illnesses are expected to increase significantly. It's estimated that Alzheimer's cases will triple within the next 50 years, for instance. If you don't already know someone who's afflicted with such a condition, you probably will sooner or later.
One of your risk factors for brain-wasting diseases is hereditary. You may be genetically predisposed to a higher likelihood of one condition or another in your later years. But regardless of your genes, there's a lot you can do to keep your brain healthy throughout your life — and to reduce the potential damage if you ever do succumb.
Many common brain-wasting diseases are largely preventable. To a great extent, these conditions are the cumulative result of poor choices made earlier in life, choices that led to habits that caused massive neural degradation and neuron death over time.
Even with the onset of such conditions, the good news is that they can often be reversed. The habits that maintain good brain health are the same habits that can help reverse many negative conditions.
Think of your brain like a muscle. If you exercise it regularly, it grows stronger. If you fail to exercise it, it grows weaker. If you fail to exercise some part of it, that part grows weaker, which can cause problems when that weakened part interacts with the rest of the brain.
To maintain a strong and healthy brain, or to strengthen a weakened one, the solution is to exercise it. If you don't exercise it, it will continue to weaken, just as a muscle grows weaker through lack of use. Just as your body has different muscle groups that you can train in different ways, your brain also has different regions that require different training methods to keep them strong.
The Three Horseman of Long-Term Brain Health
The 3 key factors in maintaining a healthy brain throughout your life are:
- Physical exercise (specifically cardio)
- Mental exercise
- Social exercise
Let's address these one at a time.
You may not think of physical exercise as a way to strengthen your brain, but your brain actually gets a serious workout when you move your body a lot. What do you think is taking care of all that hand-eye coordination, maintaining balance, regulating your breathing, etc? When you speed up your body, you speed up your brain too — it's working harder when you're exercising than when you're at rest. When you exercise, your brain lights up with activity. Even though much of this happens subconsciously, you are in fact exercising your brain, and this makes it stronger.
If you exercise with other people and have conversations at the same time — I had long talks with my sister while we did marathon training together — that's great too. Social exercise has been found to be even more beneficial in some cases than solo exercise. It's also easier for people to stick to it since they have others holding them accountable. Exercising socially gives your brain even more work to do; it gets a better workout, so the long-terms gains are better too.
As you exercise regularly for several months in a row, your brain physically changes in some significant ways. First, your individual neurons get stronger. Your brain cells work harder and faster when you exercise. Exercise stresses your neurons more than when you're at rest, and they respond by adapting to this stress; they become more efficient and more resilient. Think of it like training a muscle. Suppose you can only do bicep curls with 20 lbs, and you train up to 30 lbs. Then if you try to lift 20 lbs, it will feel lighter to you. Why? Because your arms have grown stronger. Your brain cells work the same way. When you place higher demands on them temporarily, they grow stronger, and this makes the normal, non-exercising workload seem lighter and less taxing. The net effect is that physical exercise will improve your thinking by improving the strength and efficiency of your billions of brain cells. Your underlying hardware will work better than it did before.
Second, exercise rebalances your body's production of hormones and neurotransmitters for better overall performance. Without regular exercise, these substances naturally become unbalanced relative to each other. Your body will produce too much of one and not enough of another, and this affects how you think, feel, and behave. Exercise has the effect of reducing overproduction and ramping up underproduction. The net result is that your brain functions better, especially when it comes to your experience of emotions, clarity, and alertness. If you often feel that your emotional or mental state is out of whack or that your motivation is weak, get into exercising daily to correct these imbalances. Not exercising is akin to using a toilet and never flushing it.
Third, when you exercise, different parts of your brain will actually grow or shrink in size, and these changes are mentally and emotionally beneficial. The brain areas responsible for generating negative emotions like fear, worry, and depression tend to shrink, while other regions, such as those that create positive emotions, will tend to increase in size. Essentially this means that you're going to spend less time feeling bad and more time feeling good.
I could go on for pages and pages about other positive effects of exercise, but the simplest way to put it is that if you don't exercise, you're making a really dumb decision — a decision that will literally cause you to grow dumber and more emotionally messed up as you age.
Our brains and bodies were designed to move. Lifeforms that don't move don't have brains. Plants don't need brains. Brains and movement are intricately linked. Your brain evolved in a lifeform that moves. In fact, it's best to think of your brain as being dependent on lots of body movement for its proper functioning. If you aren't moving a lot, your brain is NOT working as it should.
This need to move is so strong that if even affects us while we're still in the womb. Did you know that mothers who exercised while pregnant had kids with measurably higher IQs than mothers who didn't exercise — as measured when their kids were 5 years old? One possible explanation for this is that the extra jostling of the baby from the mother's movement gives the baby a lot more stimulation while its brain is developing, thereby helping the baby to build a stronger brain early on.
So what's the best type of exercise you can do for optimal brain health and mental performance? The answer is straightforward: cardio.
Research-wise it's well-established that cardio exercise kicks ass when it comes to brain health. Other forms of exercise like weight-training and yoga produce measurable benefits too, but not nearly as much as cardio. Partly this is because cardio has been consistently outperforming other types of exercise in human studies. But it's also because of the limitations of non-human studies that cardio has been racking up accolades the fastest.
Much health-related research begins with experiments on mice. It's easy to get mice to do cardio since mice apparently love running on mouse wheels, and they'll also run on mouse-sized treadmills. After many of these experiments, the mice are killed, and their brains are dissected to see how exercise physically affected their brains. This gives researchers the ability to directly study what's going on in the physical brain. Armed with that information, they can design different tests for humans that don't require dissecting someone's brain after a workout.
Apparently researchers haven't yet figured out how to ask mice to do weight training, yoga, tai chi, etc. Rats have been equally uncooperative. So the animal research on those other forms is much more limited, and this also limits the researchers' ability to figure out how these exercises may be affecting the human brain. The physical effects of exercise on the brain are so complex that it's really tough to guess at what's happening without cracking open the skull and poking around inside.
Despite the limitations of animal research when it comes to anything other than cardio, the research on humans still appears to be strong enough to declare cardio exercise the clear winner. Yoga will give you more flexibility. Weight training will give you stronger muscles. I can't tell you the optimal formula for fat loss since I haven't studied it enough. But if you want the strongest and smartest brain you can have, expect to make cardio the foundation of your workout regimen.
The good news is that any amount of exercise is better than none. Even 90 minutes of walking per week has been found to have measurable benefits. But again, cardio exercise is what's been measurably shown to produce the greatest benefits for brain health. It's smart to weight train. It's smart to walk. It's smart to do yoga. But it's smarter to run, to bike, to swim, etc. How much smarter? That's really hard to say because the changes are complex and systemic. But given what I've read, it's say that cardio is somewhere in the range of 2-3x as beneficial for the brain than other forms of exercise. Still... it's a bit of a stretch to say such a thing because every exercise affects the brain differently, so sometimes it's like comparing apples to oranges. I just want to help you understand that cardio isn't just a little better — it's a lot better.
For noticeable brain-boosting benefits, a good minimum to think about for cardio is 30 minutes per day at 70-80% of your maximum heart rate. A quick formula to get your max heart rate is to subtract your age from 220.
Here's an example to walk you through it: Since I'm 40 years old, my max heart rate would be 220 - 40 = 180 beats per minute. 70% of that is 126, and 80% of that is 144. So I'd want to exercise between 126 and 144 beats per minute. In other words I want to get my heart beating about twice as fast as it would be if I was sitting down resting. In practice I normally exercise in the range of 140-155, and if I do interval training, I spike it higher.
I'm currently doing 45-60 minutes x 6 days per week, plus a longer session of 90 minutes or more on Sundays, so it's an everyday activity. I also blend in interval training during some of those sessions. Normally I do this first thing in the morning.
Does having sex count as cardio? I can't say. I suppose it depends on how strenuous it is. Wear a heart monitor and find out. It could be a fun area to research. :)
It's been shown that the brain works better right after exercise. In fact, if you're a student who has to study for a test, or if you need to learn some new material, a great time to do that is right after cardio exercise. If I recall correctly, people were able to memorize items about 20% faster after exercise. That's a modest gain, but if it's convenient for you, why not give yourself every advantage?
I used to aim for 25-30 minutes minimum, but I recently cranked it up to 45 minutes minimum after reading a lot more about the brain-exercise connection. It's been shown that 30 minutes a day is measurably beneficial, but 60 minutes a day produces even stronger benefits. I'm not sure at what point you get diminishing returns, but I think 60 minutes per day is probably still on the low end and that 75 minutes might be even more beneficial, but at that point we might ask if it's worth the extra time investment for the added benefits. I also wonder about the potential downside for excessive wear and tear on the body in general, especially since I've had some occasional issues with overtraining, including a case of runner's anemia (an easily fixable problem that comes from crushing too many red blood cells as they pass through the soles of the feet when doing lots and lots of running, thereby causing major fatigue).
I'll likely continue to experiment with the duration since I'm rather curious about it. I've definitely noticed a positive difference in how I think and feel after I went from 25-30 minutes to 45-60 — it took about 3-4 days to know that something was up. This morning I remember feeling incredible as I bounced up the stairs. I've only been doing this new level for about a week, but the difference is already strong enough that I think the added time is worth it. I'll stick with it for a while and see how it goes before I consider ramping it up further.
How often? If you want to strengthen your heart, do cardio 3-4 times per week. If you want to strengthen your brain too, make it 7 days a week.
This may sound like a lot of exercise if you compare it to governmental guidelines for physical exercise, but the truth is that the government standards suck — they provide watered down advice for a society that might whine too much if they were told the truth. If low standards are your thing, go ahead and listen to the government. Otherwise you can elect me President, and I'll raise those standards to where they need to be for health, not for politics.
A heart rate monitor is a good investment to monitor your heart rate as you exercise. I have one that works great, but I rarely need it since I normally exercise on an elliptical machine with a built-in monitor that displays my heart rate on the screen continuously. The handlebars have metal grips that monitor my pulse through my hands. I can even set the machine to automatically adjust the intensity to keep my heart rate within a tight range. I've been doing cardio regularly for about 20 years now, so I have a really good pulse on my pulse... meaning that I can guess my heart rate fairly accurately just by how I feel when I'm exercising.
I can see a clear connection between how mentally sharp I feel and how regularly I exercise. During times when I slack off on exercise, I need more sleep (like an extra hour per night — that alone covers the time to exercise), I feel more mentally sluggish, it's harder to concentrate, creative writing feels a little more difficult, and I'm more likely to experience negative emotions like worry or anxiety. I also miss the very positive feelings I experience during and after exercise.
When I was taking a triple course load in college, as I wrote about on the CSW page, I made it a point to start every day by running 3 miles. Even if I had 10 or more hours of classes that day, I still ran first thing every morning. I did this because it was foolish not to. If I didn't exercise, I'd need more sleep, I couldn't perform as well mentally, and I wouldn't get as much done each day. Those 25 minutes of daily exercise kept me sharp. On top of this I frequently spent about 2-3 hours out of each day walking. Many people mistakenly think of time management as throwing hours at a task, but not all hours are equal. You may get certain tasks done 2-5x faster when you're at you're mental peak vs. when you're feeling sluggish.
Another type of exercise that's measurably beneficial for your brain (although not as much as cardio) is that which involves complex movements and coordination, such as tennis, golf, dancing, etc. Think of this as exercising different circuitry. I enjoy playing disc golf, and it's nice to know that it may have been strengthening my brain all these years.
Now these exercise suggestions are based on strengthening your brain first and foremost. If you want to compete in certain sports, to pack on tons of muscle, or to stretch your foot behind your ear, you may want to favor other types of training. But for brain health and mental performance, cardio dominates.
Weight training improves your brain. Yoga improves your brain. Golf improves your brain. Cardio improves it more.
You can also strengthen your brain by engaging in mentally challenging tasks. When you work your mind harder, it grows stronger. Just as weight training strengthens your muscle cells, mental training stimulates your neurons. Your existing neurons not only become stronger and more resilient, but you also grow more of them. The existence of neurogenesis (the growth of new neurons) is a fairly recent scientific discovery, largely coming about during the previous decade. So if you still believe that your brain doesn't grow any more neurons after you reach a certain age, your info is apparently out of date.
This assumes you're doing the extra mental work voluntarily. Being forced to perform mental labor is stressful and can actually degrade mental performance in the long run, both for humans and mice. So choosing to do it is important.
I recall that when I started learning computer programming when I was 10 years old (by choice, not by being forced), my grades in school improved. I was a decent student before then, but after I got into programming, I did much better, especially in math and science. School seemed to get easier with each passing year even as I began taking as many honors classes as I could. I ended up getting straights As through high school, and I noticed that problems that other students found very challenging were a breeze for me. One time my physics teacher had me show him how to solve a problem he couldn't figure out; to me it was no big deal. I'm sure I benefitted from all those years of rigorous mental training that were required to learn computer programming — a tough discipline. While other kids my age were playing video games, I was figuring out to write them, which is a lot more mentally challenging than playing them.
Don't shy away from difficult mental work. If you want to get smarter, then push your mind with bursts of challenging effort. Take on new hobbies that put your brain into learning mode. Your mental capacity is not fixed. Your intelligence can shrink or expand in accordance with the demands you place on it, just as your muscles can grow or shrink depending on how hard you work them. So demand a lot.
Even if you tackle problems you can't solve, it's the struggle that matters. I spent many long hours in high school trying to prove Fermat's Last Theorem. I couldn't figure it out, but it doesn't matter. I still lifted a lot of mental weight trying to figure it out, just as a bodybuilder might train to reach a certain level and fail to make it. Even when you fall short, you still get stronger. The worst thing you can do is nothing.
It's nice to know that writing 1000+ articles has been a worthwhile activity from a mental training standpoint. It helps keep my brain healthy and fit. I'm sure that public speaking has similar benefits since it really pushes me to think on my feet and takes a lot of focus. After my first 1-day workshop, my brain was dead tired, and I could barely think at all. I had the same experience after my first 3-day workshop. Now after doing 7 of them, it's getting easier, and I don't feel as tired afterwards. My brain is gradually adapting to the workload. It seems easier because my brain has become stronger at lifting these kinds of weights.
Any mental activity can fire up your neurons, even sleeping, but think about what kinds of mental gains you'd like to produce. If you want to get better at watching TV, then watch a lot of TV. If you want to get better at online social networking, spend more time doing that. But if you'd like to get better at communicating with people face to face, don't expect TV viewing and Facebooking to help much.
There is a genetic component to intelligence, and there are many ways to assess intelligence. But within your genetic makeup and natural talents, you can still build your capacity and become a lot stronger.
Your mental skills will expand or contract based on how you much you work them. Creative writing remains incredibly easy for me because I do it so often. Programming has actually grown more difficult for me since I don't do it as often. If I want to do some programming these days, I'm a lot slower at it than I was in my 20s.
Fortunately once you've trained up to a certain level once, you can retrain yourself to that level much faster than it took you to get there the first time. It's easier to reactivate old neural circuits than it is to build new ones. So while it may have taken me a decade to reach a certain level of programming skill the first time, I could probably be back up to that level with a few months of regular practice if I really wanted to. I also notice that if I haven't done any public speaking for a while, it takes me a little while to get back into the swing of it, but not nearly as much as it did to get up to speed initially.
Think about mental exercise as a form of training that will build skills that can benefit you throughout your life. What skills would you like to add to your repertoire? Would you like to improve your social skills? Would you like to learn to pilot airplanes? Would you like to play a musical instrument? Would you like to learn how to run an Internet business?
If you want to get better at anything, do that specific activity — a lot. Don't just read about it or talk about it. Do it. Use the same method you used to learn to drive a car. Get behind the wheel and drive. At first your performance will stink, but you'll eventually get good at it. Soon it will become second nature. Even if you don't practice your skill for a while, it's easy to pick it up again just by practicing some more.
Do you know how researchers raise the stress levels of mice? They take a mouse and put it alone in a cage by itself. Mice and humans function best when they're socially active. Our brains don't perform nearly as well when we deprive ourselves of socialization, especially early in life.
Being socially active works different regions of the brain than other forms of mental exercise, which is very important for your long-term mental health.
Spending too much time alone actually hastens mental decline. This is a common problem with people who retire and become less socially active.
Some voluntary solitude is okay now and then. If you want to enjoy some alone time, go for it. But even you feel okay spending a lot of time alone, it can actually make you less socially intelligent in the long run.
I remember being at a Toastmasters meeting several years ago where one club member commented that when he didn't go to Toastmasters for a few weeks, he felt like he was becoming more socially timid and fearful. Then when he got back into Toastmasters for a few weeks, he started feeling more socially confident once again. He felt it was important to keep going to the meetings to maintain a high degree of social confidence. This is like continuing to weight train to keep your muscles strong, a sensible approach if you want to avoid losing the strength you've already gained.
How much social confidence you enjoy depends on how strong your social skills are, and this will fluctuate based on how much you exercise those skills. If you spend a lot of time being very social for several days in a row, you'll tend to feel pretty confident after a while. But if you spend a lot of time alone and then enter into a social situation, you're more likely to feel a bit timid.
It's normal to feel like withdrawing and being alone sometimes. But it's not good for your mental health to overdo it. Humans are social creatures and require a lot of social interaction to exercise certain neural circuitry. If that circuitry doesn't get regular exercise, it's starts to degrade, and eventually the cells begin to die.
If you tend to feel shy, it may simply be due to a lack of sufficient training. Try being super social for several weeks, such as by going to a new meetup.com event every day or two, and notice how shy you feel after 30 days.
Being social every once in a while isn't going to do much for you. That would be like lifting weights every once in a while. You may gain a tiny amount of strength, but you'll just atrophy back down to the previous level, and there won't be any real long-term improvement. How long would it have taken you to learn to drive a car if you only practiced driving once a month? To create and lock in long-term gains, you need to engage in a certain activity frequently. Every day is good.
What if you spend a lot of time communicating online? You'll be exercising some of your social circuity, but certainly not all of it. Despite all this cool technology we have at our disposal, we still communicate best with each other face to face. In fact, our technology keeps trying to get closer to that face to face experience. We're gradually getting there — video Skyping isn't too bad — but we still have a ways to go.
Here's a good rule of thumb: Communicating online will make you better at communicating online. Communicating face to face will make you better at communicating face to face. There is some overlap between these two skill sets, but it's not as much as you might like to believe.
I've seen some people who are incredibly eloquent communicators in person, but when they communicate online they come across as dolts. Have you ever seen people make their first online forum post in ALL CAPS? Others treat them like they must be 10 years old, even though the person who made that mistake might actually be quite socially savvy in face to face interactions.
On the flip side, I can't tell you how many times I've met someone who seems very bright and social online, but when I finally meet them in person, it's like talking to a wall. They look at the ground and can barely form sentences when they speak. It's obvious they lack social confidence, and they're clearly uncomfortable. They put all their eggs in one basket, investing a great deal of time and energy in developing their online social skills, while their offline skills atrophied massively. Or perhaps they never properly developed those offline skills in the first place.
On the other hand, there are people who've built strength in both of these areas. They socially savvy and confident both online and offline. Many are either professional communicators in some fashion, or they fell into a lifestyle that gave them the opportunity to build both sides equally well. But usually people are much stronger on one side (online or offline) than the other.
Letting your face to face social skills atrophy can unfortunately lead to a downward spiral of social withdrawal, even if you stay active online. Because you aren't exercising some key skills, they degrade over time. As these skills weaken, you don't feel as confident using them. This makes you even more likely to avoid social situations, so you spend more time alone, and that makes your skills degrade even further.
The solution is that you have to bite the bullet and push yourself to be more social, such as by joining a club where you can attend regular meetings. It will seem challenging at first, but you'll gradually retrain your social skills, you'll begin feeling more confident, and then you'll experience a positive upward spiral, socially speaking. It will get easier with practice.
Keep Challenging Yourself
You can summarize the above with a simple formula:
Laziness = brain death
If you allow yourself to become physically, mentally, or socially lazy, you're slowly killing your brain.
So by the reverse of this, we have:
Challenge = brain health
Physical, mental, and social exercise all work different areas of the brain. In combination they do a great job of strengthening it holistically. Moderately stressing your brain is good for it. A temporary spike in workload encourages brain cells and brain regions to grow stronger and more resilient, so they're less likely to degrade and die so easily in your later years.
Whether you're lazy or active, the effects of your habits on your brain are cumulative but also correctable. If you go from lazy to active, you'll actually start to repair damage and reverse degradation that's already occurred. If you go from active to lazy, you'll begin to reverse improvements that have already been made. Remember the muscle analogy. If you train yourself to lift heavier weights, your muscles will get stronger. If you slack off, your muscles will weaken. Your brain works much the same way. The more you work it, the stronger it gets, but you have to keep working it.
My purpose in writing this article is two-fold. First, I want to push you further away from laziness and towards more challenge and activity — physically, mentally, and socially.
Second, I want to implant in you the idea that you can never afford to start being lazy — unless you want your brain to die a slow, wasting death. Expect to keep challenging yourself in new ways no matter how old you are. If you expect to retire someday, then take up golf and tennis and gardening, play challenging games, and stay active in clubs and social circles that have you meeting new people every week. Don't allow yourself to go stale in any dimension. If you treat retirement as your chance to escape life's challenges, then your decision to retire is a decision to expire. Stay actively engaged in life right up until the very end. Make the Grim Reaper work his ass off to catch you.
If this overall topic interests you and you'd like to learn more details about specific research related to brain health, I highly recommend the book Spark: The Revolutionary New Science of Exercise and the Brain by Ratey and Hagerman as a good place to start. I think you'll find it really hard not to exercise after reading that book.