We’ve all been there before: a tough day at work, with the kids or in school. We’re exhausted, both mentally and physically, but we still manage to push ourselves and get to the gym. Why do we do it? Because we know how much better we’ll feel after an evening indoor cycling class, an hour of kickboxing or a challenging weight workout. We leave feeling refreshed, rejuvenated and invigorated—truly transformed.
Clearly, there’s a relationship between exercise and the brain, but what is it? What creates such a dramatic improvement in mood, mental health and even memory following a workout?
Simply put, it’s the change in brain biochemistry that takes place when you lace up. The human brain is made up of cells called neurons—100 billion of them—that transmit chemical signals between each other and allow you to interpret the world, both inside and outside. These chemical signals, called neurotransmitters, are responsible for how you feel, how you think, and how you behave. There are approximately 100 neurotransmitters working in the brain to carry out a variety of functions, but two types of neurotransmitters in particular—endorphins and serotonin—are responsible for why you feel so good when you exercise. This is your brain on exercise:
If you participate in any endurance activity, from a vigorous sprint triathlon or a trot on the treadmill to a long walk with your dog, your brain releases endorphins, the neurotransmitters responsible for what some call the “runner’s high.” It’s that feel-good sensation you get after a bout of aerobic exercise. But why do endorphins leave us bathed in an afterglow of calm when we get our heart pumping? Endorphins are the body’s internal painkiller. So instead of feeling pain, endorphins leave you feeling pleasure.
Serotonin is a mood-boosting neurotransmitter and is known as the “happy chemical” because it too makes us feel good. But unlike endorphins, which initially block pain to produce pleasure, serotonin promotes pleasure itself. In fact, research has shown that a lack of brain serotonin in some individuals has been associated with depressive illness. This is also why the most commonly prescribed anti-depressant medications today work by pumping more serotonin into the brain.