Can exercise really boost your mood? Vanquish your stress? Improve your sleep? Make your brain bigger? We asked Brian Christie, a neuroscientist at the University of Victoria, to break down the science behind why exercise is good for our mental health.
Serotonin is a chemical in our brains that regulates our mood, appetite and libido, makes us less sensitive to pain and regulates our sleep cycles. When we exercise, our brains use serotonin more efficiently, which boosts our mood and alleviates depression. We sleep better, have more energy and generally feel happier. Another neurotransmitter that’s activated by exercise is acetycholine, a chemical that’s robbed from the brain by Alzheimer’s disease, which is one reason why exercising regularly may delay the onset of that disease.
Rigorous exercise, the kind that gets your heart rate up, floods the brain with endorphins, the “feel-good” chemical. Walking isn’t enough to activate this hormone, but running is, which is where the term “runner’s high” comes from. (Alternating between jogging and walking can help you ease into running.)
This may seem like a contradiction, but when we first start exercising, our brains experience a rush of stress hormones, called glucocorticoids. So why is that good for our stress levels? Because, in the long run, exercise trains our brains to better deal with stress. In studies, animals who exercise are less anxious in stressful situations, are more likely to find a solution to a problem, such as a maze, and are less likely to lose track of the goal.
Walking three hours a week for only three months makes so many new neurons that you can measure the difference in brain size. That’s because exercise increases our levels of neurotrophins, chemicals that promote the creation of new brain cells. Exercising regularly also enhances our memory and ability to learn new tasks, whereas stress impairs neurogenesis and can impede your ability to learn. Anyone that has been through a divorce or lost a loved one can tell you how hard it is to remember or learn new things during a stressful period. It’s believed that a combination of reduced neurogenesis, cell loss and changes in remaining cells can disrupt the thought processes. Of course, this takes time to happen, so usually it’s only prolonged stress that has major effects on the brain. Luckily, regular exercise can combat these negative effects, boost your brain power and make you feel happier to boot.