Exercise tells your brain to increase the density of blood vessels and help your brain cells get more oxygen and nutrients
Have you ever noticed that people who exercise a lot tend to have more energy and move around more quickly than people who don’t? Whether they’re out for a walk, grocery shopping, or browsing the romance novels at Barnes and Noble, they always seem to be moving around in a world that’s about a half speed faster than everyone else. It’s kind of like watching a mound full of mongooses – even though the next burrow is only a half step away they act like it might suddently disappear if they don’t move at warp speed: “THE PORTAL IS CLOSING, HURRY!!! Oh wait, never mind”. And the older people get the bigger the difference between exercisers and non-exercisers seems to grow. I have a lot of senior citizen friends and the ones who stay active and exercise are still more spritely and lucid than Tinkerbell with pixy-dust-a-plenty. Even when you’re having a conversation with an avid exerciser you can feel the intensity behind their thoughts, and it seems like it takes great effort for them to wait around for you to answer. It’s like they’re running high-octane unleaded when everyone else is fueled by regular. Read the next two paragraphs and you’ll understand why they’re like that.
Your brain is made up of around 100 billion brain cells, called neurons, and like all the other cells in your body, neurons need oxygen and nutrients to survive and function optimally. If they don’t get enough oxygen or nutrients they die. Here’s a clear example of this: if you have a stroke the blood supply to a portion of your brain is temporarily cut off, preventing oxygen and nutrients from reaching that part of the brain. This results in the death of millions of your brain cells within minutes. If the blood supply was cut off to the part of your brain that controls, say, your left arm, you have now lost the neurons that are responsible for helping your left arm move, leaving your arm paralyzed. Nothing is physically wrong with the arm itself, it’s your brain that was damaged, like the remote control for a kid’s toy car. But it doesn’t have to take a stroke to kill brain cells. In fact, thousands of your brain cells die every day because they don’t get the oxygen and nutrients they need to stay alive, it’s just not as noticeable because it’s not on a massive scale and happens slowly over time. However, you can imagine that the death of all these brain cells can quickly add up as you get older, leaving you with a much deteriorated brain in old age. In fact, one study found that tissue losses are as high as 25% in critical areas of your brain1! This is precisely why elderly people lose cognitive abilities as they age.
So what does this have to do with exercise? Exercise strengthens your cardiovascular system – the system responsible for carrying oxygen and nutrients to all parts of your body, including your brain, through your vast network of blood vessels. Every cell in your body needs access to a blood vessel, and if your cardiovascular system is stronger and more robust, the ability of your cells to obtain oxygen and nutrients is improved. Other studies have showed that aerobic exercise increases the density of blood vessels in the brain2,3,4 and that this is correlated to better brain function5. If your brain cells can obtain oxygen and nutrients more effectively, it allows you to think better. It also prevents the death of thousands of brain cells every day. This makes your brain more powerful, more efficient, and quicker, just like the rest of your body. After all, why shouldn’t exercise make your brain stronger if it makes the rest of your body stronger? Your brain cells aren’t some magical micromachines that were transported into your skull from another planet (though, perhaps in your case, some might argue); they run on the same basic set of physiological rules that the rest of your cells run on, requiring the same oxygen and nutrients. So if oxygen and nutrients make all those cells work better, then isn’t it pretty obvious that they would make your brain cells work better? I think so. In fact, your brain is even more susceptible to oxygen and nutrient loads than the rest of your body because even though it only takes up about 5% of your body’s mass, it uses about 20% of your total energy.
Now you know exactly why people who exercise seem to live in a world that runs in overdrive – their cardiovascular systems transfer oxygen and nutrients to their brain cells more quickly and more efficiently because they have a better cardiovascular system than people who don’t exercise. They literally flip on genes (I will talk about epigenetics in future articles) that make their cardiovascular system stronger which has a profound impact on on the power of their brawn and brain. Want some more to chew on? Try this: here is a list of the fittest cities according to Shape Magazine, and here is a list of the smartest cities according to Daily Beast. Notice any similarities? But that must just be a big coincidence, right? I don’t think so. Either way you look at – whether smarter people tend to exercise, or people who exercise tend to be smarter – I’d put on some tennis shoes and hit the pavement with “Stayin’ Alive” on your iPod and that’s exactly what your brain cells will be doing – Ah, ha, ha, ha! Stayin’ Alive! Stayin’ Alive!!!
Here’s the take-home message:
Cardiovascular exercise makes your whole cardiovascular system stronger and increases the density of blood vessels in your brain, which means oxygen and nutrients reach your brain cells more efficiently, keeping them alive and making your entire brain faster, more efficient, and more powerful. Does that sound like it might help you boost your brainpower?
- Colcombe SJ et al. Aerobic fitness reduces brain tissue loss in aging humans. J. Gerontology: MED SCI 2:176-180. 2003.
- Cotman CW, Berchtold NC. Exercise: a behavioral intervention to enhance brain health and plasticity. Trends in Neuroscience. 25:295-301. 2002
- Swain RA, et. al. Prolonged exercise induces angiogenesis and increases cerebral blood volume in primary motor cortex of the rat. Neuroscience. 117: 1037-1046. 2003.
- Creer DJ, Romberg C, Saksida LM, van Praag H, and Bussey TJ. Running enhances spatial pattern separation in mice. Proceedings of the National Academy of Sciences. 107: 2367-2372. 2010.
- Pereira AC et. al. An in vivo correlate of exercise-induced neurogenesis in the adult dentate gyrus. Proceedings of the National Academy of Sciences 104: 5638-5643. 2007.