Exercise Builds a Healthy Brain

Mood

One study of older sedentary adults who participated in three exercise-training sessions per week for four weeks reported an improved mood, quality of life, and personal morale, as well as reduced anxiety.

Another study examined the effects of long-term exercise. Older adults who were previously sedentary experienced an improved morale after a year-long training program, which included aerobic exercise three times per week.

Exercise may also alleviate depression and anxiety, which may be due in part to the fact that older people who exercise moderately on a regular basis have been found to sleep better. According to sleep researchers at the Stanford Center for Research and the Emory University Sleep Disorders Program in Atlanta, older adults who exercise spend less time trying to fall asleep and generally sleep longer and more soundly than their sedentary counterparts.

Exercise produces other benefits, such as increased muscle strength, flexibility, range of motion, balance, endurance and posture, all of which promote self-sufficiency and decrease feelings of dependence and depression.

Memory

Memory decline usually accompanies aging, but exercise may slow the progression. Several recent studies have documented the effects of exercise on memory. In one study, older sedentary adults participated in an exercise program that consisted of one hour of fast treadmill ]]>walking]]>, three times per week for four months. The exercisers, when compared with sedentary people, experienced a significant improvement in memory and reaction time tests.

These researchers also found that older adults that participated in a strength and flexibility program for one hour three times per week for four months, improved their performance on memory tests. Even though the memory-enhancing effects were more profound in people performing aerobic activity, the research shows that any type of regular exercise is better than none at all.

In another study, newly retired people who chose a more sedentary lifestyle had cognitive test scores that progressively declined over a four-year period. By comparison, new retirees who participated in regular exercise, such as walking, jogging, calisthenics, bicycling, sports, dancing, or aerobics, did not have a decline in cognitive test scores.

Brain Blood Flow and Stroke Risk

Blood flow in the brain also declines with age; this is a risk factor for ]]>stroke]]>. The same four-year study mentioned above found that the new retirees who did not exercise had a significant decline in cerebral blood flow, while those who remained active or continued to work had a more constant cerebral blood flow, suggesting that exercise helps to reduce age-related decline in cerebral blood flow and may protect against stroke.

Alzheimer's Disease

A Japanese study followed the lives of 828 people 65 years of age or older who did not have dementia over a seven-year period. They found that people who participated in daily exercise at leisure time or moderate to severe physical activity at work had a significantly lower incidence of Alzheimer's disease. Some people believe that leading a physically active life may be ]]>protective against Alzheimer's disease]]>.

How Does Exercise Affect the Brain?

Animal studies give us insight into what happens inside the brain during exercise. Mice love running, so they were given running wheels and allowed to voluntarily exercise. When compared with mice that did not exercise, the exercising mice had an increased number of new brain cells in the hippocampus—a part of the brain involved in learning and memory. Therefore, when you exercise you may increase the number of neurons in your brain. Nicole Berchtold, PhD, says, "The more brain cells the better, especially in the hippocampus. Go out and exercise to build up your muscles and brain cells."

One molecule that appears to be an important player in brain health and function is brain-derived neurotrophic factor (BDNF). BDNF is a type of growth factor that makes neurons more resistant to injury. BDNF helps neurons survive, especially neurons that are susceptible to degeneration in Alzheimer's disease and Parkinson's disease.

"We have made some exciting discoveries. We have found that exercise increases BDNF levels in memory centers of the brain," says Berchtold. "Scientists have also shown that BDNF enhances learning and memory. The exciting implications are that exercise not only keeps your neurons healthier, but exercise may also help you learn."

Scientists have shown that exercise can increase the number of brain cells as well as increase levels of protective molecules in the brain. This means that exercise has the potential to slow neurodegenerative diseases like Alzheimer's disease, or repair damaged or aged brains.

Getting Started on the Road to Exercise

So if you've decided to get moving, here are some questions you can ask yourself in deciding which activity is best for you:

• Do you enjoy company while you exercise, or do you prefer to be alone?
• Do you like the structure and companionship of a class setting?
• Do you prefer being indoors or outdoors?
• What is going to be convenient enough to fit into your routine?
• Is transportation to and from an activity a problem?
• Do you have any physical limitations that might limit the activities you can do?