Your Brain on Exercise

And those mood-boosting hormones that kick in – often called the “runner’s high” – are only part of the story. When your blood starts pumping, it sets off a series of chemical reactions that have been proven to improve memory, focus and literally increase the size of your brain. Even though you can’t see your brain chemistry changing in the same way you can notice more muscle tone in your arms, regular exercise makes your brain stronger, fitter and sharper. Here’s what happens over the course of a typical workout.

As You Warm-Up…

Let’s say you begin by getting on your favorite cardio machine. Within moments, you can feel your body heating up as your heart pumps blood to the muscles in your arms and legs. Blood is also rushing to your brain, drenching your neurons with oxygen and glucose. Can you feel it? No, but your brain cells are happily soaking up those nutrients, which have been shown to improve your memory and reaction time.

During Your Cardio Workout…

As you increase your pace, you’ll feel your heart rate rise and you might begin to sweat, huff and puff. You may want to slow down or even stop and call it a day. But stick with it because now your brain begins to release a cocktail of hormones, including the feel-good chemicals serotonin and dopamine. It might feel like you’re able to think more clearly and are less tense, which is great, but the long-term effects of these chemicals are even more powerful: They’re both key to the learning and attention processes.

Exercise also causes a surge in another chemical called norepinephrine, which positively influences perception, motivation and arousal. Congratulations: Your brain is becoming perfectly primed for learning new skills, focusing on challenging tasks and understanding complicated concepts.

These hormones also interact with brain-derived neurotrophic factor, which is involved in neuron growth and mood regulation. Scientists credit all of these chemicals with the stronger performance shown by young, aerobically fit adults on reasoning tests compared to their unfit peers.

You get those brain benefits every time you do an aerobic workout – and if you exercise regularly, the regular surge of blood and hormones actually leads to brain growth. It’s like watering a plant: Over time, it will sprout more and more leaves. In one study, researchers scanned the brains of people who exercised for an hour, three days a week over six months. Compared to sedentary adults, who did not experience brain growth, the exercisers increased the volume of their gray matter, as well as the size of their hippocampus, the part of the brain that controls memory and learning. That growth translates into improved performance in tasks that require concentration and recall – pretty much everything from doing your morning crossword puzzle to conversing with colleagues at work.

While You Lift Weights…

After you step off your cardio machine, you head over to the strength training area, pick out a set of dumbbells and begin to curl them. You’re thinking about toning your arms as you raise and lower those weights, but your brain is doing some heavy lifting, too. Researchers have found that people who train with progressively heavier weights two or three times per week for one year enjoy improved focus, attention and problem-solving, in addition to sculpted muscles and improved strength.

That’s because lifting weights triggers a spike in serum insulin-like growth factor-1 (IGF-1) levels, a compound that promotes brain cell growth and improves cognitive performance. Resistance training also reduces levels of the stress hormone homocysteine. Think of high homocysteine levels as kryptonite for a healthy brain: Studies have linked them to impaired thinking, an increased risk of brain lesions and Alzheimer’s. In fact, in one study, older subjects who trained with moderate to heavy weights three times a week for six months had better scores on memory and verbal tests compared to those who didn’t strength train.

During Your Cool-Down….

Finally, you’re ready to cool down with some gentle stretches. While you enjoy the feeling of your flushed cheeks, tingling muscles and your heart rate slowing back down to normal, you continue activating powerful brain chemicals. As you reach to one of side of your body and then the other with each stretch, your brain sends signals to your nerves that help you keep your balance. Holding stretches is also known to increase levels of the neurotransmitter GABA in the brain, providing a mood lift and reducing anxiety. Ahhh.