You undoubtedly know from your own experience that exercise elevates your mood. You can be worrying and fussing about something before you go for a walk, and each step you take seems to melt the concerns right out of your mind. After a half hour or so, you return home wondering what you were so upset about.
A recent study from Simon Fraser University in British Columbia helps explain this common experience. Your brain produces it’s own mood elevating hormones or opiods (also called endorphins) under various conditions. One of these conditions is exercise. But if you give people a blocking drug that makes it impossible for the brain to produce endorphins, they can exercise all they want and not experience the calm, pleasant feelings that usually accompany exercise. Without the blocking drug, they exercise and feel great. That’s the normal cause and effect.