Most brain chemicals are neurotransmitters that transfer electrical signals between neurons and other cells, according to the ISCID Encyclopedia of Science and Philosophy. Studies have shown that physical exercise affects brain activity--with widespread effects on the overall health of the brain.
The Brain and Its Chemicals
According to the Mayo Clinic, the brain contains billions of nerve cells "arranged in patterns that coordinate thought, emotion, behavior, movement and sensation." Brain chemicals vary in composition, but the effect of each is determined by the receptor to which it attaches--not the chemical itself.
Runner's High
A recent study at the Technische Universität München and the University of Bonn confirmed what had long been speculated--the existence of the endorphin-driven "runner's high." Endorphin is a morphine-like chemical produced by the body to suppress pain. According to Dr. Henning Boecker, who led the study, endorphins attach themselves to brain areas associated with such emotions as "music that gives you a chill of euphoria." The study revealed that the greater the euphoria, the more endorphins in the runner's brain.
Benefits of Exercise
The benefits of exercise on the brain appear most significantly in its areas of learning and memory, protection against cell degeneration and relief from depression. A study published in the Journal of Gerontology in 2003 showed that age-related shrinkage of brain tissue was less pronounced among physically active adults than it was in those who were more sedentary.
Take a Hike
Dr. John Ratey, a clinical associate professor of psychiatry at Harvard Medical School, has written at length on the science of exercise and the brain. A strong advocate of walking, Ratey says such exercise increases blood flow to the brain and with it "comes the chemical cascade that produces serotonin, brain-derived neurotrophic factor (BDNF) and other nourishing molecules."
High-Intensity Exercise
"One of the key differences between moderate and high-intensity exercise," Ratey writes, "is that once you get closer to your maximum, and especially when you get into the anaerobic range, the pituitary gland in your brain unleashes human growth hormone (HGH)." He adds that HGH "is the body's master craftsman, burning belly fat, layering on muscle fiber and pumping up brain volume. Researchers believe it can reverse the loss of brain volume that naturally occurs as you age."
