How exercise combats the effects of stress
I am currently reading the book Spark by John Ratey, MD. It’s a fascinating read that provides insight into the biological relationship between exercise and improvements in stress management, mood, and other conditions such as Attention-Deficit-Hyperactivity-Disorder.
Ratey references a number of scientific studies in his book and makes it relatable and engaging by incorporating case studies. I love case studies. My favorite profs were those that went “off piste” during class and talked about patients or crazy family members/friends. I thought using a case study for today’s blog post may be kind of interesting…
Take Jonas. He’s a rising star at the marketing firm he has been working at for 5 years. He works hard to manage his time at the office in order to sustain a personal life, but is finding that he is spending a lot more time indoors in front of his computer lately. Recently his sleep patterns have become strange – not able to fall asleep, but still getting up early. He has also noticed that his memory is foggy – when asked by friends if he remembers their road trip 6 years ago, he has trouble recalling. His pants have also felt a bit snug lately. He doesn’t quite know what is going on, but realizes he has put physical activity on the back burner. He decides to start rowing again.
Let’s briefly talk about stress. When you’re stressed, your body responds accordingly. You experience the fight-or-flight response. You have a surge of endorphins and release the hormone cortisol. Cortisol promotes fat storage (hence the expanding waist line) and also influences your hippocampus. What’s that? Your brain memory bank. Cortisol excess causes a cascade of events that eventually lead to the breakdown of neurons, and prevents the development of new neurons right in the memory bank. In the brain, we have neurons by the billions. So losing a few isn’t bad (which is happening all the time), but losing a lot to stress is not good – it actually leads to decreased brain volume in your hippocampus and other areas.
OK back to our case study. So after two weeks of rowing Jonas feels better. His sleep patterns have become more normal and as he expected, his pants are starting to fit a whole lot better. What he is most surprised about is his the improvement in his memory and his work efficiency. So what’s happening?
During exercise, your body releases a whole lot of endorphins. Sound familiar? It should. Exercise is a stress so your body is going to respond the same way it always does. However exercise has some very different and positive effects on the brain that differ from the fight-or-flight response.
Exercise stimulates this little guy called insulin-like growth factor-1 (IGF-1). In the brain this handy little protein increases neuroplasticity, and neurogenesis in the hippocampus…more simply, it’s working to increase the volume of your memory centre.
Another really cool mechanism by which exercise works is through the heart. When you exercise your heart releases atrial natriuretic peptide (ANP) which makes its way up to the brain and slows down your neural stress pathway. I guess you could say your heart is talking to your brain and saying “cool your jets my friend”.
On the more behavioural side of things, planning and performing exercise helps you gain a sense of mastery and confidence. You start to believe in your ability manage your stress without a substance, food, or emotional turmoil but by using your body. This is an empowering feeling, one that I believe our friend Jonas discovered as he hasn’t stopped rowing in 5 years.
If you are stressed and haven’t exercised in a while, try it out. Just go for a walk. Do something simple. Come home and write down how you feel. Keep writing down how you feel including the days when you don’t exercise. I would be interested to know what happens…