How Exercise Revs Up Your Brain U.S. News & World Report

April 17, 2008 12:09 PM ET | Katherine Hobson | Permanent Link

When I'm in a blue funk, going for a run helps me feel a lot better. And prolonged periods of inactivity—say, after a big race—make me anxious, and something close to depressed. There are certainly a host of reasons why exercise seems to improve my mood (the Justin Timberlake on my iPod and the view from the Brooklyn Bridge, for example), but one potential factor is the idea, supported by a growing body of research, that physical exertion itself has a much bigger influence on the brain than previously thought. Just this week, a survey of existing research published by the Cochrane Library concluded that the same aerobic exercise that is good for your heart also improves cognitive function—specifically, motor function, auditory attention, and memory—in healthy older adults.

That's only one piece of what has become a burgeoning field. In Spark: The Revolutionary New Science of Exercise and the Brain, published earlier this year, psychiatrist John Ratey explores the neuroscience behind potential beneficial effects of aerobic exercise on anxiety, stress, depression, learning, aging, and even attention deficit disorder. (Research hasn't as fully explored the effects of anaerobic exercise or more passive activities like stretching and yoga.) "Even people who are overweight and who start exercising see improvements in mood and cognition in as little as 12 weeks," he says. One study found that exercise improved depression symptoms as well as medication.

A host of mechanisms are thought to be responsible. As U.S. News reported earlier this year in a story about keeping your brain fit, studies in rodents showed that running led to an increase in new brain cells in a part of the brain called the hippocampus that plays a large role in learning and memory. Researchers don't count brain cells in studies of live humans, but one study of regularly exercising adults did show increased blood flow to the same area. Because of the obvious implications for age-related memory lapses and dementia, much of the human research in this area has been in the elderly, says Henriette van Praag, a researcher in the neuroplasticity and behavior unit in the laboratory of neurosciences at the National Institute on Aging. She's now studying (in rodents) whether the progression of neurodegenerative diseases like Alzheimer's can be slowed by exercise.

Some studies have looked at kids. They haven't yet shown that getting exercise causes improvements in concentration and learning, but "what we agree on at this point is that there's a strong association between aerobic fitness and performance on standardized testing, grades, and other measures of cognitive performance," says Darla Castelli, a researcher in the department of kinesiology and community health at the University of Illinois-Urbana-Champaign. She was an investigator on a study published last year in the Journal of Sport & Exercise Psychology that looked at the relationship between physical fitness and academic performance in 259 third and fifth graders. Aerobic exercise (as well as BMI) was related to achievement in reading and math. Now she's preparing to start a study in August that will compare cognition in a group of kids who participate in an after-school physical activity program with a group that does not.

Chemicals influenced by exercise, including neurotransmitters and growth factors, are being investigated for their role in mood and brain function. Even runner's high, that elusive euphoria that some people experience after prolonged or intensive running, is becoming clearer—literally. A study done in Germany, published in March in Cerebral Cortex, used PET scans to look at the brains of 10 athletes following a two-hour run. The scans confirmed that during the run, endorphins were released in certain parts of the brain known to be involved with the processing of emotions. But while endorphins may cause the runner's high, they're not the sole regulators of mood and emotions during a workout. "A lot of things contribute to us feeling better when we exercise," says Ratey. "Endorphins are one of them, but so are norepinephrine, serotonin, dopamine, and brain-derived neurotrophic factor (BDNF)."

So you're sold. How much do you need to work out to get these fabulous brain benefits? "Something is better than nothing," says Ratey. As little as 10 minutes of brisk walking can quench the urge for a cigarette for over an hour, he says, and Castelli notes that a single 10-minute bout of physical activity in an academic setting boosts attention and problem-solving skills in kids. A study published online earlier this month in the British Journal of Sports Medicine found that mental health benefits were observed after 20 minutes of physical activity, though the more exercise and higher intensity, the better the effects. Which means that doing the recommended 30 minutes a day of aerobic activity will cover your brain as well as your heart.

http://www.usnews.com/blogs/on-fitness/2008/04/17/how-exercise-revs-up-your-brain.html

John's Comments

Since Spark was published there have been a number of new studies that support the fact that exercise improves cognition in school children. Most recently a study from the CDC shows that especially in girls those that had the most physical activity per week consistently scored higher on tests with the greatest impact on math scores.

http://www.usatoday.com/news/health/2008-03-04-phys-ed-study_N.htm

Another study looking at the effects of 20 and 40 minutes a day of exercise showed an improvement on executive function scores and possibly on math tests in both boys and girls who participated in a study to help see how exercise can help reduce obesity in our children.

http://www.eurekalert.org/pub_releases/2007-10/mcog-eit102207.php

Anecdotal studies are pouring in and larger more well planned studies are underway to further study the effect of exercise on cognition in children, a fact that has been studied and deemed so in the elderly by a report out yesterday by the Cochrane Library an international organization that evaluates medical research . This report by a very conservative and  cautious review board now deems that along with the obvious positive  effects on the body,  taking up exercise improves the cognitive function in people over 55 years of age, regardless of whether or not they show  signs of cognitive impairment.

http://www.news-medical.net/?id=37449

http://mrw.interscience.wiley.com/cochrane/clsysrev/articles/CD005381/frame.html

Comments

[Lokes]

Amazing. This article is giving clue to new patterns. Thanks for the nice info.

[Daniel Piper, NSCA-CPT, CSCS, DC]

Read the book...Loved it...I tell all of my college students to read it...and then tell them what they need to know...what they need to teach their clients. and I tell all of my patients and clients about it.
Question: Have you seen this article http://www.fmnetnews.com/basics-news.php#hippocampal and how do you think this fits?

[Phil McMally]

Hi John 'Champion of Exercise',

I am interested to read of the benefits of exercise for both males and females. Is exercise was more or less (or same) beneficial for females than for males?

I just wondered if different types or intensities of exercise might suit males and not females due to previous evolutionary roles.

(men hunted; ran and walked for miles)
(women gathered; water, berries and nurtured children)

any comments and papers I should read appreciated

thanks

Have a great day!

Phil McNally
Positive Psychology Coach

Blog: http://www.veryhappyphil.com
Book: 'Winning Mentality - 7 Mind Techniques used by Winners'

[Dr. Charles Parker :: CorePsych]

John -
To make the connection easier for the review:

http://www.corepsychblog.com/2008/09/addadhd-book-re.html

Thanks again,
Chuck

[Dr. Charles Parker :: CorePsych]

John,
Your book has so much to offer everyone on so many levels. I do think we should all build exercise into our everyday recommendations for recovery from any brain challenge.

Most appreciated from my perspective is the depth of commentary and research in Spark- and your writing is so engaging.

I just posted a short review over at my site, and hope that others find the BDNF as interesting as we do!
Chuck

[Norman]

Dr Ratey,

could you please discuss this article I just found :

http://www.medscape.com/viewarticle/578933

"A large, longitudinal population-based study in identical twins found the twin who exercised more did not display fewer anxious or depressive symptoms than the twin who exercised less."

How should these results be understood ?

Thank you for your help,

Best regards

ps: I bought your book and I am currently reading it.

[Kathleen]

Dr. Ratey - thanks so much for putting this information together in such a readable format!
I have a request: please do what you can to get this out in audio format with an upbeat, energetic reader. Your book is one I would listen to repeatedly while doing my 5 to 7 hours of treadmill at the gym with a heart rate monitor. It's too easy to 'fall off the wagon' of exercise, and the right audio book helps keep me motivated. I can't tell you how many times I've been through 'Younger Next Year'!
Thanks again,
- Kathleen C.

[Nick Matheson]

Thank you for your comments.

That is interesting about mood and anxiety. I guess it is likely the output of "stress energy." I have even read that strength training can cause more depression in depressed individuals, though I guess this is further reason to look at individual prescription and recovery ability.

I think a lot of people experience a great deal of systemic inflammation, often because they do not allow adequate recovery before stressing themselves again. Or they have too much nutritional stress and not enough resources or time for the rebuilding phase. I completely agree with everything you say for kids who are in (or should be in) a naturally anabolic state. For adults, that begins to get a bit more complicated and requires far more than general admonitions and guidelines.

[John Ratey]

Comment from Dr Ratey:

It certainly is an issue that people need to start gradually and then increase as it is reasonable or face the threat of injury. I emphasized the aerobic conditioning much more than strength training though i include mention of the need of strength training in many chapters and report that most of the results for brain fitness show that aerobic conditioning is a little bit better than strength training as far as mood, anxiety, aging goes but i emphasize the effects on brain function that we get when we stress our muscles to the point of overwhelming them which if we allow them to recover leads to growth. This is also a process which sends off many factors that are important for our brains to learn, grow, and develop resiliency to face the stress and aging challenges of the future.

In fact most recently there is evidence accumulating that suggests that challenging and building our muscles as we age, is one of the major ways to keep our stem cells dividing to try and replenish the eroding hippocampus, the major memory control center in the brain. The same factors (FGF-2, VEGF to name a few) that are released when the muscles are damaged by adequate strength training and lead to the development of more and fitter muscles fibers and new blood vessels to service them, that these travel up to the brain and keep our stem cells dividing. They are called “mitogens” which means they start the cells they target to reproduce and in the muscles case repair the damaged, overtaxed muscle fibers and in the brain keep those stem cells dividing. Within the last year, there have been two papers with conflicting views of aging, one that suggests that the slow down in “neurogenesis” is due to the lack of these mitogens and that it is not the case that our supply of stem cells dwindle, however other papers suggest that in fact our number of stem cells in the brain drop so science goes forth. But in any case, strength training and muscle damage and repair are helpful to the brain in so many ways and certainly help maintain our carriage to go through life with less trouble.

[Nick Matheson]

Dr. Ratey, I think your book is great, but I have a few questions anc concerns. As a physical therapist I see the downside of activity a lot as well. Pain and injury are frequent side effects of the great medicine that is exercise when it is not prescribed properly. Although I think physical activity is essential, structured exercise, especially in the form of resistance training, increases in importance as someone age. Exercising in order that you may be active is an important distinction. Although you touch on it, your book seems to underplay the role of strength training and also does not define recovery particularly well. Could you provide a bit more information / research regarding your position on these two topics?

Thanks.