As I dive into the second to last part of this series, I think it’s best that I transport you back circa the 80’s and 90’s when the iconic “This is Your Brain on Drugs Campaign” started circulating as we dissect what is happening in our brains when we engage in physical activity.

This is your brain. This is your brain when you exercise. Any questions?

If you don’t get the reference, you clearly were not aggressively hit with the anti-drug campaign that featured an egg and a frying pan. Fortunately, you don’t need to understand the reference in order to understand what happens in our brains when we exercise and how this influences more than just our physical appearance.

I’m sure when your favorite influencer is breaking down an exercise or hypertrophy they focus on how to build the muscle, feel the muscle, or activate the muscle (a rant for another day, but your muscles are always active or you wouldn’t be standing, sitting, whatever - it’s not that it needs to be activated it needs to be strengthened appropriately but I digress), but do they talk about what signals this is in turn sending to the brain? I’m guessing they don’t, but they should. When your muscles contract and put in work as you exercise, they secrete chemicals that function as messengers to the brain, such as cyclic AMP and Irisin. These chemicals induce the brain to start pumping out neurotransmitters, such as serotonin and dopamine which improve mood (think Elle Woods “happy people just don’t kill their husbands”). In addition, engaging in physical activity stimulates the production of growth factors in the brain, such as IGF (insulin-like growth factor), VEGF (vascular endothelial growth factor), and BDNF (brain derived neurotrophic factor).

For the sake of this series, we are going to focus on BDNF because it is commonly referred to as “Miracle Gro” for the brain. Exercise, such as resistance training, promotes BDNF in the brain and leads to neurogenesis, the growth and formation of new neurons, and causes existing neurons to become more efficient. It acts on the DNA of neurons and causes more transcription of genes that favor brain growth. As these new neurons are formed and the old ones become more efficient, your brain is becoming more plastic and we are setting the stage to create new connections and pathways within the brain. However, the new pathways are not automatically created. BDNF builds the infrastructure for learning but you have to add a learning skill to it in order to create these new connections and feedback loops in your brain and then reinforce the connection via repetition and consistency - this takes us back to the adaptive brain theory and neuroplasticity. The learning skill can range from implementing a new habit or coping mechanism to learning a new movement pattern - it truly depends on your goals and what you are trying to accomplish.

Outside of growth factors, exercise also increases neural plasticity by increasing perfusion and angiogenesis - big fancy words to say that we are increasing blood flow and the number of blood vessels. If you think all the way back to my discussion of the structure of the brain, it is filled with blood vessels and nerve cells. The blood vessels lead into capillary beds in the brain that deliver oxygen and glucose to nerve cells. As the number of capillary beds increases, it facilitates the delivery of these compounds to neurons and increases neural plasticity as a result. In summary, when you exercise there is more happening than just breathing hard and breaking a sweat. You are setting the stage to train your brain and develop connections that facilitate growth in all aspects of your life. Now that we’ve set the stage, let’s bring it all together with R7’s Core 3 in our last and final installment of this series.