How does physical exercise help keep my brain healthy?

Exercise promotes blood flow to the brain and supplies the cells with oxygen and nutrients; in addition, it seems to boost brain hormones that help keep you focused, lowers memory-damaging amino acids and prevents—or possibly reverses—the natural brain shrinkage that begins in middle age.

Taiwanese researchers found that middle-aged mice trained to work out on a treadmill every day for five weeks grew 2.5 times more new brain cells than mice that didn’t work out. Not only was the quantity of brain cells superior in the mice that worked out, but the quality of these cells was as well. Also, mice that began exercising in early middle age fared even better than mice that took to the treadmill in later middle age.

Researchers at the University of Edinburgh in Scotland studied physical fitness and cognitive function in 460 human subjects, all surviving participants of the 1932 Scottish Mental Health Survey. They reviewed IQ data from the earlier study and administered the same cognitive test that participants had taken at age 11 to the 79-year-olds, looking at verbal reasoning, numerical and spatial skills. Then they tested their physical prowess, including grip strength, 6-meter walk time and lung function. What the researchers found was that higher fitness levels at age 79 were a significant predictor of higher cognitive test scores, indicating that physical fitness has a direct correlation to successful cognitive aging.

Keep Your Wits by Walking

A University of Illinois study used magnetic resonance imaging (MRI ) to measure brain volume in nearly 60 seniors. Half of the group was then put on a brisk walking regimen—one hour per day, three times a week—while the rest were assigned stretch-and-tone exercises. “After only three months, the people who [walked] had the brain volumes of people three years younger,” observed study coauthor Arthur Kramer, PhD. MRI s revealed no such improvements for the stretch-and-tone group, leading researchers to believe that walking pumps more blood to the brain, which in turn fuels the growth of new neurons.

Exercise to the Beat for an Extra Boost

A study in the New England Journal of Medicine found that among 450 seniors, all age 75, those who danced several times per week had the best defenses against mental deterioration. “The combination of music and exercise may stimulate and increase cognitive arousal while helping to organize cognitive output,” said study author Charles Emery, PhD.

Aerobic activity that gets the heart rate up for extended periods of time boosts brain-derived neurotrophic factor (BDNF), a chemical that plays a role in neurogenesis, or the growth of new brain cells. Think of BDNF as a sort of Miracle-Gro for your brain. When you exercise, your brain sprouts new cells. When your brain doesn't create as many new cells as it loses, aging occurs.

Research studies show that exercise generates new brain cells in the temporal lobes (involved in memory) and the prefrontal cortex (involved in planning and judgment). These new cells survive for about four weeks, then die off unless they are stimulated. If you stimulate these new neurons through mental or social interaction, they connect to other neurons and enhance learning. This is why you have to exercise consistently to encourage continual new cell growth in the brain. It also explains why people who work out at the gym and then go to the library are smarter than people who only go to the library.
Physical exercise boosts blood flow to your brain, quickly delivering more oxygen and nutrients to your neurons. Regular exercise is one of the best things you can do to keep your brain healthy and sharp -- plus it encourages new brain cell growth. If you are feeling tired, cranky or having a hard time focusing, just take a brisk walk! Have you ever heard the term, “runner’s high?” It really is possible to feel that good, just from exercise! Exercise immediately boosts focus and mood while helping to reducing anxiety and cravings for food or other substances. It truly is the closest thing to a “happiness pill” that you will ever find.

These conditions are particularly influenced by exercise:
Mood and Depression: Activating the same pathways in the brain as morphine, exercise stimulates the release of our feel-good neurotransmitters: norepinephrine, dopamine, and serotonin. Research shows that people who are depressed are more likely to be overweight, and conversely, that weight problems increase the risk for depression. Getting regular exercise will help you to get depression under control and lose the extra pounds—also boosting self-esteem and confidence -- all at once!
Anxiety: Physical activity of just about any kind and at any intensity level can soothe anxiety. In particular, high-intensity aerobic activity has been shown to reduce the incidence of panic attacks.
Focus and Attention: Vigorous exercise boosts brain blood flow and oxygenation, which immediately improves focus and concentration abilities. For those with ADD/ADHD, vigorous daily exercise is a must.
Sleep: Regular exercise is extremely beneficial for insomnia, but don’t do it within 4 hours of hitting the sack. Vigorous exercise late in the evening may be too energizing and keep you awake.
Alzheimer’s and Dementia: Studies show that exercise is helpful for boosting blood flow and activity in the parts of the brain linked to Alzheimer’s and dementia, such as the hippocampus -- the brain’s memory center.

So how much exercise should you get? I recommend that everyone do the equivalent of walking “like you are late” for 30-45 minutes, four to seven days a week. No brain injuries please! Avoid contact sports like football, hockey, boxing, and soccer (headers). Coordination exercises like dancing and table tennis require new learning, which are extra-beneficial for keeping you sharp as you age!

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.