The huff and puff of a workout builds more than just muscle. People exercise for a wide variety of reasons ranging from weight loss to bodybuilding to racing. All of those training goals focus on developing cardiovascular and muscular strength but what if all of that work is doing more? What if I told you that exercising builds your brain function? The affects of exercise on the brain often go overlooked but actually are a crucial aspect of exercise. While working out you might bulk up the body but you also build brain mass, balance out neurotransmitter levels, and increases learning capacity. I just finished reading the book Spark: The revolutionary New Science of Exercise and the Brain by John J. Ratey and Eric Hagerman. This book takes the leading proven psychological and physiological research to illustrate what is happening during and post exercise.
The book starts off telling the story of a small school district in Illinois. This school district had struggled with the state and national standardized tests for years. It took a revolutionary approach by one gym teacher to flip the results leading to the school becoming one of the highest scoring schools on the famed Program for International Standards test. What did it take to make this giant leap? Running one mile before school and a slight reorganization of classes. The goal of gym class was switched from the typical sport oriented teaching method to the fitness and health based program. The program went by the name Zero Hour because of the fact that kids would run a mile prior to starting the day. So why did running a mile prior to the school day make such a large impact? The answer is simple; exercise increases Brain-Derived Neurotrophic Factor. In simple terms, BDNF encourages the survival and growth of neural connections. BDNF is key in learning, memory, and critical thinking which are critical for education. BDNF, while a major part of the success, is actually just one benefit of exercise.
Brain-derived neurotrophic factor increases the ability to learn and remember but this increase is only temporary post exercise. During exercise, neurotransmitters are increased like glutamate, serotonin, and dopamine. In order to take full advantage of the increased BDNF you need to immediately go into cognitively challenging tasks. BDNF leads to the creation of new neurons and glutamate increases electrical signaling for these neurons. Left untouched these neurons will just fade away. According to Hebb’s theory of activity dependent neural plasticity, if neurons go unused then they will “die.” This goes to the saying “If you don’t use it, you lose it.” the Zero Hour program took this knowledge and applied it by placing challenging classes early in the morning or immediately after recess. These classes provided the actual material for the brain to fire signals to the neurons. Due to the increased glutamate the signals were stronger which lead to the strengthening of the neuron and axon. When the signal remains strong the brain will begin to strengthen that connection by insulating the axon in the mylon sheath (white matter). This insulation insures that whatever you are learning will stick.
Next thing to cover is serotonin and dopamine which are the key pleasure and focus neurotransmitters. Most of the athletes reading this can relate to the old “Runner’s High”. This is that feeling of euphoria and pleasure post workout. Dopamine and serotonin are key players in this phenomena. Serotonin’s purpose in the body is to modulate mood, appetite, and sleep. I just want to focus on the mood aspect though. Serotonin has the ability to increase one’s ability to feel happiness and overall well-being. This adds to the longer lasting aspect of runner’s high. The immediate feeling of satisfaction and pleasure is actually due to dopamine levels increasing. Activity in dopamine neurons, called the nucleus accumbens AKA pleasure center, increases and peaks immediately post exercise. The increased activity is also what happens when someone takes drugs. One theory about why drug addicts keep coming back for more is that it comes down to motivation. The strengthening of the pleasure center leads to increased motivation to return to that stimulated state. While drug addicts are motivated to use drugs again, people who activate the center using exercise become more and more motivated to continue with that exercise regimen. Pairing the increased dopamine levels with learning will translate some of that motivation towards learning, making it more exciting. Another cool aspect of dopamine is its ability to control neural noise. Dopamine reduces neural noise; taming down inputs in your environment allowing you to focus.
Alright, so one thing that I remember seeing in college a lot was students bringing their study material to the gym. It was their attempt of utilizing every moment they had available to study. I can’t blame them for that! What I didn’t know at the time was that this was actually hindering their ability to absorb the material! During high intensity exercise (80-90% max heart rate) blood flow is significantly decreased to the prefrontal cortex, crucial aspect in learning. Additionally, glucose levels are significantly decreased in the prefrontal cortex during high intensity exercise. This means the strength of neural firing is reduced. While most of the people trying to study during exercise are actually at a much lower heart rate, there is still going to be a shunting of blood to this area of the brain. Luckily, blood flow and glucose levels are restored immediately after conclusion of the exercise. This means it is probably just best to leave the studying to after the workout. Use the exercise time to clear your mind and increase those critical neurotransmitters.
It is amazing what goes on in the body during and after exercise. Everyday I learn about some new amazing aspect of what the body is doing during exercise. The incredible thing is that to get the benefits I just described it really only takes 10 minutes of moderate aerobic exercise. 10 minutes a day gives you the ability to be a smarter, healthier, and more stable human. All you have to do is just get started. Find a tool or routine that gets you moving. Buy a jump rope and bring it wherever you go or walk briskly to your next meeting or class. Take advantage of what your body wants to naturally do!