Some of you probably already know that exercise is very beneficial for dealing with stress, depression, anxiety, addiction, etc. However, what I have recently come to discover is that exercise is ridiculously and utterly the ultimate form of helping your brain become the best it can be, whether that be for people with mental health issues or without them. I have recently read a book called Spark by John J. Ratey, MD that has changed the way I look at exercise. I will give you the break down of the chapters and the tidbits that I thought to be interesting and useful. But don’t just take my word for how insightful this book is. Find out for yourself. You can buy it on amazon here.

The main chapters in the book are Learning, Stress, Anxiety, Depression, Attention Deficit, Addiction, Hormonal Change and Aging, and how exercise impacts each of them.


The effect exercise has on learning is profound. Our understanding of how the brain and body connects is at the peak and yet there is still so much to continue learning. An important molecule, or rather collection of proteins, is showing us something very interesting. “I’m talking about a family of proteins loosely termed factors, the most prominent of which is brain-derived neurotrophic factor (BDNF). Whereas neurotransmitters carry out signaling, neurotrophins such as BDNF build and maintain cell circuitry – the infrastructure itself” (Ratey 38). You’re not going to be able to build a pretty house, full of colours, artwork, and literature, without the foundation, cement, bricks and wood for which the house was built with and which holds it all together. The foundation is BDNF (so to speak) and the artwork is whatever you want it to be. Learning is considered to be known as long-term potentiation (LTP). The ability to hold on to information, process, apply it, etc. And what do you know! BDNF has been shown to correlate with LTP. “In a 2007 study of humans, German researchers found that people learn vocabulary words 20 percent faster following exercise than they did before exercise, and that the rate of learning correlated directly with levels of BDNF” (Ratey 45). BDNF is stored and only released when we get our blood pumping. Exercise = BDNF = LTP.

Another thing to note is the myth of brain cells dying and never coming back. Cells do die, but they grow back by the thousands, as a blank slate, however. Upon stimulating the newly grown cells with challenges of reading, learning a new skill, or simple walks around nature, they get assigned jobs and help your brain ‘grow’. This process is called neurogenesis. Exercise increases the amount of cell regrowth and neurogenesis exponentially. So all that worry about how you want to keep your brain smarts and not kill them with drugs or alcohol, good news, they’ll grow back. So drink and smoke as much as you want right? False, excessive drinking or drug abuse will not be overcome by simple neurogenesis. So, have a couple shots but don’t black out and wake up next to a homeless man who looks like he just had the best night of his life.

Stress, Anxiety and Depression

Cortisol. That bastard. In stressful situations it’s our Goldilocks. We want it to be just right. Too much or too little and it starts to reveal its true colours and causes horrible erosion and other problems on our brains.

When talking about stress we’ll break it down to our fight, flight or freeze response. We are creatures of survival and with stress comes the ability to realize that we are in danger. It is a gift from evolution. Cortisol is used to help us think our way out of stressful situations, or at least help us realize we are in them, by boosting cellular energy in the brain (glutamate). However, we are unfortunately very imaginative beings and can think ourselves into a frenzy without actually being in stressful, anxious or depressive states. Cortisol levels and other factors get out of line and cause neural damage and even erosion. Without physical movement the cortisol is put to no use and overloads the brain. “You have to make a conscious effort to initiate the physical component of fight or flight” (Ratey 68).

“In the context of stress, the great paradox of the modern age may be that there is not more hardship, just more news…The negative and the hectic and the hopeless heap on the stress, but we figure we can handle it because we always have – up to a point. Then, we just want to relax and take a break, so we grab a drink and plop down in front of the TV or go sit on a beach somewhere… obesity has doubled in the past twenty years… our lifestyle today is both more stressful and more sedentary” (Ratey 69).

Anxiety is a form of fear that is closely related to stress. It actually happens “at a certain point in the stress response when the sympathetic nervous system and hypothalamic-pituitary-adrenal (HPA) axis shift into high gear” (Ratey 87). The HPA axis basically controls your reaction to stress. With anxiety, levels of cortisol are still being overloaded and one is still at risk of brain erosion. Hopefully, that thought doesn’t cause you more anxiety.

Depression. So complex and misunderstood. “One of the hurdles to conquering depression is that the disorder encompasses such a broad array of symptoms, most of which all of us experience at some point” (Ratey 114). It starts becoming serious when the symptoms are prolonged and bring around other symptoms. The mechanical cause is that the happy hormones and neurotransmitters are not reaching your brain, at least not in the way they should be. (Dopamine, Serotonin, Norepinephrine, GABA, BDNF, etc.)

So what is the role of exercise in all of this and how does is combat/control these conditions? The effects are as follows;

  1. Controls the negative feedback loop of ongoing stress (an outlet)
  2. Regulates cortisol and the HPA axis (through ANP)
  3. Produces BDNF and GABA to rebuild the erosion of cortisol
  4. Produces the same molecules and effects as anti-stress, anxiety and depression medications

People with serious conditions should not drop their prescriptions and think that aerobic exercise will erase their problem. It is not that simple, but having exercise completely out of the equation, in my opinion, makes the solution unattainable.

ADHD, Addiction and Hormonal Changes

ADHD and addiction are very subjective. Not for someone who is shooting up meth but for perhaps for someone drinking too much, a rambunctious kid, or a clean freak. Definitions of addiction and especially ADHD have changed throughout the years, but the underlying principle stays the same; an imbalance of brain functions.

“Given the leading role of dopamine and norepinephrine in regulating the attention system, the broad scientific explanation for how exercise tempers ADHD is by increasing these neurotransmitters…. With regular exercise, we can raise the baseline levels of dopamine and norepinephrine by spurring the growth of new receptors in certain brain areas” (Ratey 158). With exercise, it not only acts as a regulator but a master to the firing of neurotransmitters, telling them how to act and behave like a second mother to her kids.

With addiction, the enemy is the habit loop. The brain mistakes the vice as a necessity to survive. Literally, the brain thinks that it needs the vice to survive. Now think how hard it must be to overcome addictions and drop them cold turkey. Nevertheless, exercise can help with this too. Dopamine cravings can help be controlled through exercise, as the neurotransmitters that fire during exercise help control dopamine fixtures. Also, “researchers found that exercise dramatically reduced withdrawal symptoms in rats, the signs of withdrawal are identified as “wet dog shakes”, writhing and diarrhea” (Ratey 179)… very nice.

If you’ve been getting the message so far, exercise is like a regulator and a builder. The guard, seeing and attending to whom enters and exits the ‘castle’ and the builder who built the castle itself. For hormonal changes, ladies, exercise would lean towards the regulator. PMS, pregnancy and menopause have all been combined with exercise to dramatically reduce the negative symptoms. Just like depression, postpartum depression will be significantly reduced through practiced aerobic exercise.

Again, this does not mean to drop the pill bottles, go for a bike ride and expect your problems to disappear. Balancing, being patient, prioritizing and finding enjoyment through exercise, knowing that it is doing all these wonderful things for you, should be the first step.


Oh boy, this is the mother-load, know why? Because we are all, once more, going to be wearing diapers. No way around it. However, as you will see… you might not have to melt away in a hospital or nursing home as soon as you may think. Or quite possibly, you may not need to even enter the doors.

First, what is aging? Well, it is basically your cells or synapses getting older and weaker and therefore, unable to fight off diseases, as well as keeping up with general maintenance. (Another reason why fasting is so beneficial for longevity, see fasting post, here). “If the synaptic decay outpaces the new construction, that’s when you start to notice problems with mental or physical functioning, ranging from Alzheimer’s to Parkinson’s disease… all neurodegenerative diseases stem from dysfunctional and dying neurons” (Ratey 222). BDNF and another nurturing neurotrophin, vascular endothelial growth factor (VEGF), trail off as you age as well. “Starting at about age forty, we lose on average 5 percent of our overall brain volume per decade” (Ratey 223).

So, what is known to increase BDNF? Exercise! It also promotes VEGF. Neuroscientist Arthur Kramer did a study comparing subjects aged sixty to seventy-nine, having some exercise and some not, then comparing the outcomes after six months. MRI scans of the exercising patients showed increased brain volume in the frontal and temporal lobes. Carl Cotman, the man who linked exercise and BDNF says that the idea of increasing brain volume in that short a time is kind of out there. Nevertheless, Kramer says that it is a form of turning back the clock, in terms of circuit functions.

To Conclude

These are only sections from a 250+ page book. There is a lot of information that is missing, as the book goes into much more detail and scientific data. As you may get the gist of it by reading this, there is a lot more to learn by reading the book itself.

Exercise is not a one and done deal. Nor is it the sole aspect of living a long and healthy life. It is only a piece of the pie and with a little more knowledge of how it will help your mental and physical life, I hope you all incorporate a little more aerobic practice into your life.

Once again you can purchase Spark by John J. Ratey, MD, here.

To quote one of Dr. Ratey’s patients; “Exercise saved my life. I think running really put me back with the unitary nature of body and mind – it’s all one thing, We’re not split into pieces.”

1 Comment


This site uses Akismet to reduce spam. Learn how your comment data is processed.