Do you exercise, and if so, does it benefit you?
Most of us exercise because we know it is good for our physical health. The opportunity for fun with friends and social interaction is enjoyable too.
Would you also agree that exercise makes you feel better….more invigorated and positive? It’s a great way of lifting those occasional sombre moods and of ‘re-booting’ your brain. I certainly feel sharper and more focused after a good swim, walk or workout.
But is there any solid ‘scientific’ explanation for how and why exercise apparently boosts brainpower?
Yes. Empirical research shows exactly how exercise works not only to tone your mid-section, but also your mind! Your brain is no different to your muscles in the respect that--you either use it or you lose it!
As John Ratey (ref. 1) Harvard Medical School psychiatrist and author of “Spark: The Revolutionary New Science of Exercise and The Brain,” says, “Exercise is the single best thing you can do for your brain in terms of mood, memory and learning.”
How exactly does Exercise Re-Boot Your Brain?
Physical exercise has positive effects on brain function in many ways ranging from the cellular to the behavioural. For example, exercise has been shown to:
- Increase the heart rate, pumping more oxygen rich blood to the brain, and, thereby improving memory formation in healthy young adults, as well as improving reaction time (ref. 2 ) Better yet, the physical activity doesn’t have to be gruelling to increase blood flow. Mild activity like a leisurely walk may help to increase blood flow, fend off memory loss and keep skills like vocabulary retrieval strong.
- Aid the release of several hormones, including growth factors, all of which help to provide a nourishing environment for the growth of brain cells. This in turn boosts our learning capacity. Research from UCLA (ref. 3) demonstrated that exercise increased growth factors in the brain - making it easier for the brain to increase plasticity and grow new neuronal connections.
- Encourage the same antidepressant-like effects associated with "runner's high". A Stockholm study (ref. 4) showed that the antidepressant effect of running was also associated with more cell growth in the hippocampus, an area of the brain responsible for learning and memory.
- Increase levels of serotonin, dopamine and norepinephrine, three brain-soothing chemicals which ease tension and stress. Researchers from the UCSF claim this benefit happens with only 30 minutes of jumping on a treadmill or cross trainer.
- Further, according to the same study (ref. 5), not only will exercise reduce stress, it may reverse the toll stress takes on the aging process by intervening on a cellular level. After stressed-out study participants exercised an average of 45 minutes a day over a three-day period, their cells showed fewer signs of aging than inactive study participants’ cells.
In a nutshell, working out keeps you younger!
Different Exercise Styles = Different Brain Benefits
Interestingly, several studies show how differences between exercise styles, such as cycling versus walking have different brain benefits. For example, one study (ref. 6) showed how ballroom dancing has a greater benefit on cognitive functioning, especially in protecting against age-related cognitive decline, than exercise or mental tasks alone.
This indicates that the best brain health workouts may involve those integrating different parts of the brain such as coordination, rhythm, and strategy. Ballroom dancing involves all these as well as physical demands as dancers must carefully coordinate and synchronise with their partner.
A meta-analysis (ref. 7) on the effects of exercise on cognitive function in older adults concluded that:
- exercise programs involving both aerobic exercise and strength training produced better results on cognitive abilities than either one alone
- more than 30 minutes of exercise per session produces the greatest benefit
All these examples illustrate the brain boosting benefits of exercise, but they don’t really explain the underlying biological mechanism behind WHY exercise has positive benefits on boosting brain power, and especially memory ability.
Do you have any idea?
I didn’t until I unearthed a pivotal Irish study.
The Key Biological Reason Why Exercise Boosts Brainpower
The Irish study (ref. 8) is significant because it clearly showed how and why exercised volunteers performed significantly better on memory tests than the volunteers who had rested and did not improve.
Using blood samples before and after exercise, and samples from the non-exercisers, the researchers noted that immediately after the strenuous activity, the cyclists had significantly higher levels of a protein known as brain-derived neurotrophic factor, or BDNF. This is known to promote the health of nerve cells (refs 9-10). The men who had sat quietly showed no comparable change in BDNF levels.
For some time, scientists have believed that BDNF helps explain why mental functioning appears to improve with exercise. However, they haven’t fully understood which parts of the brain are affected or how those effects influence thinking.
The Irish study, as well as other research, suggests that the increases in BDNF prompted by exercise may play a particular role in improving memory, recall and possibly other brain functions.
Perhaps the most revealing of the recent experiments is one involving aging human pilots (ref. 11). For the experiment, scientists at Stanford University School of Medicine asked 144 experienced pilots ages 40 to 65 to operate a cockpit simulator three separate times over the course of two years.
For all of the pilots, performance declined somewhat as the years passed. A similar decline with age is common in all of us.
But in this case, the decline was especially striking among one particular group of men. These aging pilots carried a common genetic variation that is believed to reduce BDNF activity in their brains. The men with a genetic tendency toward lower BDNF levels seemed to lose their ability to perform complicated tasks at almost double the rate of the men without the variation.
While the pilot experiment wasn’t an exercise study, it raises the question of whether strenuous exercise could slow such declines by raising BDNF levels, thereby salvaging our ability to perform skilled manual tasks well past middle age.
One of the researchers Dr Salehi says: “So many studies have shown that exercise increases levels of BDNF. Other growth factors and body chemicals are “upregulated” by exercise, but BDNF holds the most promise. The one factor that shows the fastest, most consistent and greatest response is BDNF,” he says. “It seems to be key to maintaining not just memory but skilled task performance.”
In other words, appreciating how BDNF works, helps us understand how exercise positively affects the brain in so many ways.
Is Too Much Exercise Bad for the Brain?
As with too much of anything, excess exercise may have negative effects on the body and brain. Not only does it appear to reduce BDNF levels, it also shrinks the brain!
Studies (ref. 12) show how extreme sports such as ultramarathons, may lead to “a volume reduction of about 6% “. Compare that with ‘normal’ physiological brain volume reduction during aging of less than 0.2% per year. Fortunately, it appears that the shrinkage is reversible in time, as long as the excess exercise does not continue.
Here are some exercise tips to help you boost your brain and body power:
Exercise Tips for Boosting Brain and Body Power
Remember how you read above that different exercise styles have different brain benefits? So, the key recommendation is to aim for a well-rounded fitness program which includes:
- High-Intensity Interval (Anaerobic) Training: This is when you alternate short bursts of high-intensity exercise with gentle recovery periods.
- Strength Training: You need enough repetitions to exhaust your muscles. The weight should be heavy enough that this can be done in fewer than 12 repetitions, yet light enough to do a minimum of four repetitions. It is also important NOT to exercise the same muscle groups every day. They need at least two days of rest to recover, repair and rebuild.
- Core Exercises: Your body has 29 core muscles mostly in your back, abdomen and pelvis. They provide the foundation for movement throughout your entire body. Strengthening them can help protect and support your back, make your spine and body less prone to injury and help you gain greater balance and stability. Exercise programs like Pilates and yoga are also great for strengthening your core muscles.
- Stretching: Particularly recommended is “Active Isolated Stretching” where you hold each stretch for only two seconds. This works with your body's natural physiological makeup to improve circulation and increase the elasticity of muscle joints.
As I hope this blog has made clear, re-booting and maximising your brain and body power are inter-related. The body is like a finely tuned orchestra and nothing happens in isolation. The ball room dancing illustration above showed how exercise activities which combine several attributes – physical, intellectual and social - may positively affect different aspects of the brain and help with better overall synchronisation. When done in moderation of course!
No matter how busy you are, fit in 30 minutes of exercise daily. It is likely to benefit your biceps and your brain! I try to combine several of the above tips with daily short bursts of running on the beach followed by five minutes of speed swimming in the sea. It really gets me going for the day!
What exercises do you enjoy? Can you see and feel the body and brain boosting benefits?
1. For more on John Ratey, see http://johnratey.typepad.com/
2. Benefits of boosting oxygen rich blood to brain, including the impact on memory:
3. Research from UCLA showing how exercise increases growth factors in the brain http://www.ncbi.nlm.nih.gov/pubmed/15159540
4. Stockholm study showing antidepressant effect of running http://www.ncbi.nlm.nih.gov/pubmed/15769301
5. UCSF study showing the effect of exercise on stress and aging http://www.ucsf.edu/news/2010/05/4411/brief-exercise-reduces-impact-stress-cell-aging-ucsf-study-shows
6. Different exercise styles have different brain benefits http://www.google.com.ag/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCcQFjAA&url=http%3A%2F%2Fwww.heritagepines.net%2Fpicture%2Fsave_your_brain_ways_to_fight_age.doc&ei=Y9JvU5jvNte2sAT7kIHwDg&usg=AFQjCNFbmH-AWcDHAWVySu5dV0Pt9SCDCg&bvm=bv.66111022,d.cWc
7. Meta-analysis on the effects of exercise on cognitive function in older adults: Colcombe, S. & Kramer, A.F. 2003. Fitness effects on the cognitive function of older adults: A meta-analytic study. Psychological Science, 14, 125-130.
8. Irish study showing the underlying biological mechanism – BDNF - for some of the beneficial effects of exercise on the brain http://www.ncbi.nlm.nih.gov/pubmed/21722657
9-10. How BDNF supports the survival of existing neurons, and encourage the growth and differentiation of new neurons and synapses
11. Study on Pilots http://www.nature.com/tp/journal/v1/n10/full/tp201147a.html
12. Negative effects of too much exercise on the brain