Maybe you know that you always feel better after you exercise but you don’t really know why. On a chemical level, exercise increases BDNF, IGF-1, VEGF, FGF-2, serotonin, dopamine, norepinephrine, and epinephrine. All of these chemicals play a VITAL role in optimal brain function (peak at the glossary below if you want more details about these chemicals). The cool thing about exercise is that it helps to bring many of the chemicals in your brain to an equilibrium, versus drugs that selectively increase one or the other. Additionally, Dr. Ratey talks a ton about the hippocampus and the amygdala which are two areas of the brain that are affected not only in mental health disorders but also in aging and stress. The hippocampus is key in memory and the amygdala plays a vital role in our emotions. Dr. Ratey cites NUMEROUS studies about how exercise can reverse damage in both of these areas of the brain.
Although this book dedicates a chapter each to learning, stress, anxiety, depression, ADHD, anti-aging, addiction, and hormones, I am only going to touch on stress. ALL of these topics are important and I would encourage you to grab this book and give it a read if you want to learn more, but I know stress plagues almost ALL of us at some point in our lives. I want to shed some light on the damaging effects stress can have and what we can do about it to reverse the damage and thrive.
Did you know that chronic stress can lead to anxiety and depression?!
Stress. We’ve all got it in one form or another. And the truth is, the body doesn’t discriminate between good stress and bad stress. To the brain, stress IS stress. However, the brain can identify stress in varying degrees. Do you know that saying “too much of anything is a bad thing?” The same thing goes for stress. Chronic stress floods the brain with cortisol which can have damaging effects over time.
Unfortunately, our lifestyle today is both more stressful and more sedentary. According to Dr. Ratey, our average energy expenditure per unit of body mass is less than 38% of that of our Stone Age ancestors and our caloric intake has also risen. Something else I’ve found profound, especially in the middle of a pandemic is that he writes, ”the great paradox of the modern age may be that there is NOT more hardship, just more news’’. We’ve got constant communication about the country via the internet sitting in the palm of our hands and the TV blaring the news everywhere we look causing the amygdala to literally FLY (think emotion center of the brain). Raise your hand if your anxiety has risen tremendously during this pandemic, mine sure has! So this just heaps on the stress and when we want a break, instead of exercising, we relax on the couch or beach and grab a drink. Hello, obesity rates skyrocketing! This behavior creates a negative feedback loop of stress, causing a vicious cycle that is damaging to our bodies and our brains. Stress elicits the fight or flight response in our sympathetic nervous system, while relaxation elicits the rest and digest response of our parasympathetic nervous system.
The fight or flight response plays a major role in our stress response and was made to trigger our bodies that we are in a potentially harmful situation that we need to get out of, and fast! Because human being’s circumstances and society have continued to evolve while our biology has mostly stayed the same, we’re left with this response meant to literally keep us alive, yet our lives are much safer and predictable. The unique thing about human beings is that we don’t even have to be in danger to elicit the fight or flight response. This probably helped in the savannah when our lives literally depended on it, but it can be detrimental to our health and wellbeing nowadays. We can literally THINK ourselves into a frenzy! (Hello, anxiety about the pandemic). Have you ever done that? You’re thinking about something you’re worried about, and your heart rate starts to kick up, you’re starting to sweat, and your blood pressure is rising. These are all physical symptoms of the fight or flight response. Your brain is also releasing adrenaline in the form of various chemicals which leads to a cascade of events at the cellular level as well. But remember, stress isn’t inherently bad. Too much stress with no way to mitigate the symptoms is problematic.
But, here’s some GREAT news. Because the purpose of the fight or flight response is to mobilize us to act, physical activity is the most NATURAL way to prevent the negative consequences of stress. When we exercise in response to stress, we’re doing what we have evolved to do over the past several million years. We can literally run ourselves out of our frenzy! Just as the mind can affect the body, the body can affect the mind!
Regular aerobic activity can control the emotional and physical feelings of stress while also working at the cellular level. It calms the body so that it can handle more stress before the serious responses involving your heart rate and stress hormones kicks in-meaning it literally raises the threshold for the physical reaction. Although exercise is a form of stress, it is much milder, and assuming you are allowing proper recovery time for neurons, repair mechanisms strengthen neuronal connections allowing our “mental machinery” to work better. Exercise makes cells MORE resilient.
So, the next time you’re stressed out I challenge you to WORK OUT. Lace-up your shoes and go for a run or walk outside. And if you can grab a friend, do it. Human beings thrive on human connection-we weren’t made for isolation. Studies have found that even isolation can elicit a stress response on our bodies. Dr. Ratey recommends aerobic exercise at least 3-4x/week for 30-60 minutes to reduce the physical, emotional, and cellular effects stress has on the body. But here’s the catch, the more stress you have, the more exercise you NEED to mitigate the symptoms! Want more details, grab a copy of Spark here!! You will not be disappointed!
Happy sweating y’all!
Annie Robertson PT, DPT
Glossary:
BDNF: Brain-derived neurotrophic factor; Ratey describes it as miracle grow or fertilizer for the brain.
- Fun fact: exercise boosts BDNF at least as much as anti-depressants and sometimes more in rat studies.
IGF-1: (Insulin-like growth factor) Increases Long Term Potentiation, neurogenesis, and neuroplasticity in the brain helps manage glucose levels,
VEGF: (Vascular endothelial growth factor) build new capillaries and expand the vascular systems in the brain
FGF-2: (fibroblast growth factor) build new capillaries and expand the vascular system in the brain
Serotonin: chemical in the body that contributes to happiness and wellbeing
Epinephrine: chemical is also known as adrenaline; increase HR, blood sugar, relaxes airways to enhance fight or flight response
Norepinephrine: chemical very similar in function to epinephrine but also narrows blood vessels to increase blood pressure.