Benefits of Exercise and the Brain

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The Human Brain

When you think of the word “exercise” the brain is probably the last thing that you think about.  Flexing muscles, moving limbs, expanding lungs and a racing heart are obvious images that come to mind … not the explosion of activities going on in the brain.  We know that when we exercise our bodies benefit in many ways depending on the type of exercise we do (i.e. healthier, more efficient heart, stronger muscles, fat loss, muscle gain, improved health and vitality).  But how does the brain benefit from exercise?

Neuroscientists over the past 20 years are starting to better understand the changes that occur in the brain to different types of exercise and how they affect our cognitive, sensory and motor behaviors.  They are also uncovering how exercise can help treat (and possibly prevent) psychiatric disorders like depression and anxiety.  Exercise has also been shown to help with neurological disorders like stroke, Alzheimer’s disease and Parkinson’s disease.

Researchers have identified three ways exercise affects the brain:
  1. Improves cognitive function
  2. Changes brain function
  3. Changes brain structures

Fun Facts About the Brain

Many of us know very little about the brain, even though we rely on it for everything we do!  Before we discuss how exercise effects the brain, let’s learn a little bit about the human brain.  Below are a few “fun facts” about the brain to help you better understand how it functions and what it does.

  • The average brain weighs approximately 3 lbs. and has approximately 100 billion neurons.
  • The brain has about 100,000 blood vessels.
  • The brain is 75% water.
  • The brain uses approximately 20% of the total oxygen of the body at rest.
  • As long as your brain is involved in mental activities you will continue to make new neurons throughout your lifetime.
  • Excessive stress has been shown to alter the structure and function of brain cells.
  • The average number of thoughts a person experiences each day is about 70,000.
  • You can’t tickle yourself because the brain can tell the difference between your own touch and unexpected touch.
  • While you are awake, your brain generates 10 to 23 watts of power (enough to light up a light bulb).

To access more fun information about the brain at the Nursing Central Assistant website, click here to access the “100 Fascinating Facts You Never Knew About the Brain” article.

Exercise Improves Cognitive Function

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flickr Photo Credit: Saad Faruque

In simple terms … exercise improves how our brain processes thoughts.  A growing body of research shows that physical activity is associated with improvements in brain function and cognition during childhood and throughout adulthood. Studies in older adults suggest that aerobic activities, in particular, can produce significant improvements in areas that include working memory, planning, scheduling, multitasking and dealing with doubt and uncertainty (Kramer et al., 2006).  These are known as “executive cognition functions” and are often areas of substantial decline with aging.  On the flip side, growing evidence shows that a sedentary lifestyle negatively affects the brain by decreasing mental capacity over time.

To access the Reviews in the Neurosciences article on physical activity on cognition in adulthood, click here. To access “The Association Between School-Based Physical Activity, Including Physical Education and Academic Performance” (published by the Centers for Disease Control and Prevention), click here.

Exercise Changes Brain Function

The brain is made up of approximately 100 billion neurons (nerve cells).  It is incredibly dynamic and responds to exercise in much the same way that heart, lungs and muscles do.  As it is exposed to new experiences it adapts to become more effective and efficient over time.  Each exposure to an activity trains the brain to improve overall coordination, decrease response time and perform better.

In comparisons between sedentary people and active individuals, the active participants show greater overall brain function and more activity in certain areas of the brain than their sedentary counterparts (primarily in the cerebral cortex).  To access the “Frontiers in Human Neuroscience” article, click here.

Exercise Changes Brain Structures

The central nervous system (including the brain) has the capacity to change its structure and function in reaction to the constantly changing environment (i.e. what we see, what we hear, what we do, how we respond, etc.). In simple terms, the more we do and experience … the more connections our brains require to do the work effectively.

Exercise appears to change the structure of the brain by prompting the growth of new nerve cells and blood vessels.  It also increases the production of neurochemicals that promote growth, differentiation, survival and the repair of brain cells.  To access the “Journal of Applied Physiology” article, click here.

Exercise Benefits and the Brain – Final Thoughts

Physical activity has been shown to have multiple positive effects on brain function over a person’s lifetime. Unfortunately, nothing is known regarding what exercise design (i.e. type, intensity, duration or frequency) is the best prescription for improving brain health most effectively.  Most studies to date have used cardiovascular exercise as the type of physical activity, all with positive results.  It will be interesting to see future research and publications for more concrete recommendations.