Exercise floods your brain with molecules that help you think better
This is the last of the four articles I will be writing in my “Exercise Boosts Your Brainpower” foundational series. These foundational articles are for those of you who want to understand why exercise boosts brainpower. The other three articles about Vascularization, Neurogenesis and Cell Power described how exercise increases the density of blood vessels in your brain, increases the number of new brain cells you make every day, and increases the amount of power each brain cell has, respectively. If you haven’t read them, I would highly recommend you do because understanding why exercise boosts your brainpower always improves motivation for wanting to exercise. I will still be writing more articles about exercise and the brain, including articles about actual scientific studies and what kind of exercise you should do, but these four foundational articles will help you understand the why behind exercise.
And this article is perhaps the most important article because none of the other three things would happen – increased vascularization, neurogenesis, or cell power – without signaling molecules. Your brain wouldn’t grow more blood vessels, wouldn’t grow new brain cells, and wouldn’t create more mitochondria without signaling molecules telling it to do so.
Let me illustrate this concept with something you can relate to: lifting weights. People who go to the gym and lift weights get bigger and stronger, and those who go the most often and lift the heaviest weights tend to be the biggest, strongest people at the gym (although, admittedly, having bulging biceps that help you curl 80s or blasting your pecs so you can rep 315 on the bench press may not actually have any function other than impressing yourself when you look in the mirror!). Nonetheless, a gym rat, let’s call him Buff Arnold, will always be beefier than a pencil neck with a penchant for video gaming. Just look at the picture in the header!
So the important question is: Why does Buff Arnold get buffer and buffer? The answer is because every time he works out and puts his muscles, tendons, ligaments and bones under stress, his body reacts by sending out molecules that tell him to grow more muscle, tendon, ligament and bone cells, and make the ones he has even more efficient and powerful. And that is why Buff Arnold gets buffer and buffer. The human body is a marvelous thing because it adapts to the different stresses we put it under so that we are better prepared the next time that same stress comes up.
It turns out that the molecules released when exercising, whether cardiovascular or strength training exercise, don’t just affect your muscle, tendon, ligament and bone cells – they also affect your brain cells and blood vessels, encouraging more growth, power, and efficiency. And just what are these molecules and what do they do? Here is a list of the most important molecules that are upregulated (fancy science-talk for “you get more of them”) when you exercise:
BDNF, brain-derived neurotrophic factor
The BDNF protein acts on neurons in your brain to promote their survival and encourages the growth and specialization of more brain cells. It is found in the highest concentrations in your hippocampus, the part of the brain associated with learning and processing new material, and the cerebral cortex, the part of the brain that helps you with higher thinking and stores memories. Cardiovascular exercise greatly increases the concentration of this molecule in your brain1.
IGF-1, insulin-like growth factor 1
IGF-1 is another protein that promotes the survival of existing cells and encourages the growth of new ones. The levels of IGF-1 and BDNF are strongly correlated and it is thought that your brain must have adequate levels of IGF-1 in order to promote angiogenesis2 and neurogenesis3. Strength training significantly increases levels of IGF-1 in your brain4, as does cardiovascular exercise5.
NGF, nerve growth factor
NGF, a small protein, was the first growth factor to be discovered. NGF helps promote old cells to survive, maintain themselves, and grow. NGF has the largest impact on sensory neurons, however, it is still seen in elevated levels in the brain after exercise and does have an impact on certain brain neuron types6.
VGF, VGF nerve growth factor inducible
VGF is a protein that regulates cell metabolism, homeostasis and synaptic plasticity (the ability of neurons to change shape and function). BDNF helps your body produce more VGF, which is expressed in higher levels in the central (brain) and peripheral (body) nervous systems after exercise7.
FGF2, fibroblast growth factor 2
FGF2 is a protein that is expressed in the extracellular matrix of blood vessels, encouraging the growth of new blood vessels in the hippocampus, the area of your brain heavily associated with learning8. As you may recall, this is called angiogenesis. The growth of new blood vessels is very important for improving the vascularization of your brain, which helps get oxygen and nutrients to your brain cells more effectively.
VEGF, vascular endothelial growth factor
VEGF is another vascular growth factor that promotes the growth of existing blood vessels, angiogenesis, and is also required for the formation of brand new blood vessels in growing embryos, called vasculogenesis. However, in relation to the brain, VEGF is also apparently required for the growth of new neurons in the hippocampus9.
Galanin is a small neuropeptide that is important for helping neurons determine when to fire, a process called an “action potential”. You could say that since it helps neurons figure out when to fire, it plays a role in making your brain more efficient and helping you create memories for important things and dismissing unimportant information. It is also found be an important growth factor in the brain10.
Neurotransmitters: Dopamine, Serotonin, Acetylcholine
Neurotransmitters are molecules that the neurons in your brain use to communicate with each other. Every time a message is passed from neuron to another neurotransmitters are released so the signal can carry on to the next neuron in the chain. More of these neurotransmitters are released after exercise11,12,13, and this can help you make synapses – the connections between neurons – stronger. This means you can process information faster and form long-term memories more easily.
Isn’t it incredible that exercise boosts the levels of all these proteins, peptides and molecules, and as a result improves your brain’s vascularization, boosts neurogenesis, and increases the number of mitochondria in your brain cells?! That’s one helluva elixir if you ask me. Try to get some mad scientist or health store nut to beat that concoction.
So here’s the take-home message:
Exercise boosts the concentration of growth factors in your body, including several neuron and blood vessel growth factors and neurotransmitters. These molecules don’t just help your muscles get bigger, they also help your existing brain cells survive and become more powerful, promote the growth of new brain cells, help you learn things faster and build long-term memories more easily. So you better get moving if you want your brain to get bigger. And who knows, maybe someone will also notice your svelte physique or bulging muscles and will also like you for you body, not just your brain!
- Rasmussen P et. al. Evidence for a release of brain-derived neurotrophic factor from the brain during exercise. Experimental Physiology. 94: 1062-1069. 2009.
- Lopez-Lopez C, LeRoith D, and Torres-Aleman I. Insulin-like growth factor I is required for vessel remodeling in the adult brain. Proceedings of the National Academy of Sciences. 101: 9833-9838. 2004.
- Trejo JL, Carro E, and Torres-Aleman I. Circulating insulin-like growth factor I mediates exercise-induced increases in the number of new neurons in the adult hippocampus. Journal of Neuroscience. 21: 1628-1634. 2001.
- Cassilhas RC et. al. The impact of resistance exercise on the cognitive function of the elderly. Medicine and Science in Sports and Exercise. 39: 1401-1407. 2007.
- Carro E, Trejo JL, Busiguina S, and Torres-Aleman I. Circulating insulin-like growth factor I mediates the protective effects of physical exercise against brain insults of different etiology and anatomy. Journal of Neuroscience 21: 5678-5684. 2001.
- Molteni R, Ying Z, and Gómez-Pinilla F. Differential effects of acute and chronic exercise on plasticity-related genes in the rat hippocampus revealed by microarray. European Journal of Neuroscience. 16: 1107-1116. 2002.
- Hunsberger JG et. al. Antidepressant actions of the exercise-regulated gene VGF. Nature Medicine. 12: 1476–82. 2007.
- Gómez-Pinilla F, Dao L, and So V. Physical exercise induces FGF-2 and its mRNA in the hippocampus. Brain Research 764: 1-8, 1997.
- Fabel K et. al. VEGF is necessary for exercise-induced adult hippocampal neurogenesis. European Journal of Neuroscience. 18: 2803-2812. 2003.
- Van Hoomissen JD, Holmes PV, Zellner AS, Poudevigne A, and Dishman RK. Effects of beta adrenoreceptor blockade during chronic exercise on contextual fear conditioning and mRNA for galanin and brain-derived neurotrophic factor. Behavioral Neuroscience. 118: 1378-1390. 2004
- Poulton NP, and Muir GD. Treadmill training ameliorates dopamine loss but not behavioral deficits in hemi-parkinsonian rats. Experimental Neurology. 193: 181-197. 2005.
- Blomstrand E, Perret D, Parry-Billings M, and Newsholme EA. Effect of sustained exercise on plasma amino acid concentrations on 5-hydroxytryptamine metabolism in six different brain regions in the rat. Acta Physiologica Scandinavica 136: 473-481. 1989.
- Fordyce DE, and Farrar RP. Enhancement of spatial learning in F344 rats by physical activity and related learning-associated alterations in hippocampal and cortical cholinergic functioning. Behavioural Brain Research. 46: 123-133. 1991.