Posted Nov 27, 2011
DAYTON, Ohio — Scientists know that a healthy diet and regular exercise are vital to maximize brain functioning.
Regular aerobic exercise has been shown to improve reaction time, speed of processing information, memory and attention.
Aerobic exercise has even been shown to reduce the symptoms of depression.
Recommended levels of physical activity include at minimum three weekly sessions of 20 minutes or more of aerobic activity that is intense enough to elevate the heart rate, and two to three days weekly of anaerobic activity (resistance training).
Exactly how exercise benefits the brain is still a mystery, but it is likely that there are multiple factors at work. For example, until relatively recently, neuroscientists believed that adults never produced new brain cells, or neurons, the basic building blocks of the nervous system. It was thought that we were born with a set number of neurons that could not increase, and with age these neurons and other brain cells died off.
We now know that not only is the brain capable of creating new neurons, but there is evidence indicating that regular exercise stimulates this regeneration.
Neurotransmitters are the chemical messengers of the brain.
Unfortunately, the number we produce declines as we age. However, studies show that exercise appears to increase the production of neurotransmitters such as norepinephrine, serotonin and dopamine.
These so-called “feel good” chemicals can have positive effects on both thinking and mood, and the proper balance of these chemicals is critical to maintaining a healthy brain. Other beneficial brain chemicals that appear to be stimulated by breaking a sweat are neutrophic factors, proteins that are responsible for helping neurons survive, adapt and grow.
Another plus is the beneficial effect that exercise can have on circulation. Proper blood flow is vital to both cellular waste removal and delivery of essential nutrients responsible for proper brain function, such as oxygen and glucose (blood sugar).
In addition to increasing overall blood flow, exercise has been linked to the production of new blood vessels in the brain. In the absence of regular physical activity, the brain’s system of veins and arteries can become clogged, interfering with processes necessary to feeding and cleansing brain cells.
Lumosity.com, a leading website devoted to helping spread the word about methods to improve brain health, cites interesting research establishing a positive link between cardiovascular fitness and cognition.
Dr. Arthur Kramer at the Beckman Institute at the University of Illinois says that there may be a link between cardiovascular fitness and the size of the hippocampus, a portion of the brain critical for the formation of new memories.
Elderly adults who were physically fit tended to have larger hippocampi than their less fit counterparts.
While exercise has been linked to hippocampus size and spatial memory in rodents, this if the first study to demonstrate a similar relationship in humans.
Although the degree varies depending on the individual, it is well established that the hippocampus typically shrinks with age and that this is associated with subtle but definite declines in memory and spatial orientation.
Marjie Gilliam is a certified personal trainer and fitness consultant. Email: marjie@ohtrainer.com. This article appeared in the Dayton Daily News.