By Dr. William Sears and Dr. Vincent M. Fortanasce

Remember Dr. Mom’s prescription for boredom and bad behavior? “Go outside and play!” No neuroscientist has ever topped this advice from Dr. Mom. Modern brain scans, those windows into your brain, reveal she was right. In our medical practices we often use phrases like, “You’re suffering from the indoor disease” or “You have NDD—nature deficit disorder.”

“Nature is the best medicine,” one of the oldest and wisest pieces of advice, is even more fitting in today’s artificially stimulated and overloaded society. Nature neuroscientists teach that once we started working and playing indoors instead of out, we started losing our minds.

More movement while spending time outdoors is good brain medicine. Movement in nature, we believe, reminds your brain, “This is how you were genetically wired thousands of years ago. Welcome back!” Sitting indoors in windowless rooms staring at artificial light is a mis-fit for the mind.

As neuroscientists Eva Selhub and Alan Logan mention in their book Your Brain on Nature, “Green exercise is like exercise squared.”

Brain-Healing Benefits of Nature Therapy

When we take a brisk walk in the woods, a new medical specialty, the neuroscience of nature, has proven that we:

  • make more happy hormones (serotonin, dopamine).
  • mellow our moods.
  • lower our stress hormones (cortisol).
  • lower our heart rate.
  • lower high blood pressure.
  • lessen neuroinflammation.
  • prevent and delay dementia.
  • create smart ideas.
  • think happier thoughts.
  • feel more “positive.”


Suppose you know you feel good when you enjoy the great outdoors, but you want to know why. So, on your way to the park, you stop by your friendly neighborhood neurologist. At the appointment desk, you announce, “I’m here to get wired.” The receptionist smiles and escorts you to a room where you get fitted with a cap full of wires that is remotely connected to an MRI scanner that is going to record what’s going on in your brain while you walk in the woods.

As you begin your walk, you smell the roses, look at the trees, and take deep breaths to smell the leaves. You feel good. Meanwhile, back at the neurologist’s office, the MRI scanner is showing why. Areas in your brain, called the parahippocampal gyrus, release natural happy hormones, opiates and dopamine. As you take in more delights of nature, the MRI shows your brain dialing up the relaxation centers of your brain and dialing down the hyper, or anxious, centers of your brain, also called the arousal centers—the parts of your brain that get revved up during rush-hour traffic.

As you continue your walk, you notice the nature effect: your mental fatigue, or brain fog, is much less while viewing the scenes of nature than during your morning commute. You’re feeling more “positive.” You like yourself more and appreciate what you have. You leave the park feeling happier and healthier, both physically and mentally.

Go outside and play, lower your stress. Measurements of stress hormones in body fluids (saliva, urine, and blood) show that stress hormones drop when we move outside, too. In a study done by the Department of Forest Medicine of Nippon Medical School in Japan, levels of adrenaline in the urine of participants who spent a day of walking in the woods decreased by nearly 30 percent. The stress hormone levels dropped even more in the women in the study than they did in the men.

Go outside and play, make more DHEA. Neuroscientists have also discovered that spending time moving outside increases a hormone called DHEA, which helps maintain the level of brain-growth fertilizer. Unfortunately, DHEA can decrease as we age—if we let it. The older we get, the higher the dose of go-outside-and-play we need.

Go Outside and Play: “Re-Create”

During a walk in the woods, Dr. Bill had an “aha!” realization. Recreate should mean getting involved in an activity that reminds the brain (re-minds) where it feels and thinks best: the outdoors. A “recreation center” with a basketball court, swimming pool, and ping-pong tables can be good indoor medicine for the mind, especially in nasty weather. But to really “re-create,” go outside and play.

Tired While Multitasking?

Ever notice how your brain gets tired and foggy during multitasking? Back to the “brain as symphony orchestra” analogy. Ideally, the entire orchestra, and its conductor, is focused on playing the piece in front of them—say, the “Blue Danube” waltz. Beautiful music results. Suppose, however, that a few players let their attention wander to another piece. Disharmony results.

Neuroscientists call this split focus attention fatigue. Trying to process too much at once results in distraction and mental exhaustion from our efforts to focus despite that distraction. Recognizing this new attention fatigue disorder, neuroscientists came up with a solution to the problem, which they refer to as “cognitive restoration” or “attention restoration therapy” (ART). Translation: Take a break, go outside and play!

Take a Think-Walk

You’ve heard the sage advice, when you’re facing a tough problem, to “sleep on it.” Try “walking on it” instead! Thoughts come together, distractions tend to disappear, and mental clarity blossoms during a walk. Double that for walking in nature.

Much of this book was written while walking, each chapter dictated into a recorder; Dr. Bill’s current average is one-and-a-half to two hours a day.


As we’ve seen, movement is good medicine for your mind and body. If you were to do a literature search on the medical benefits of movement in nature, you would discover they exceed any store-bought drug:

  • Lessens stress
  • Releases happy hormones
  • Reduces the pain threshold
  • Grows a bigger and smarter brain
  • Makes the antis: antidepressants, anti-anxiety, anti-inflammatories, and antioxidants
  • Helps heart health
  • Improves lung function
  • Facilitates digestion
  • Eases arthritis
  • Lessens type II diabetes
  • Reduces inflammation

Even knowing all these benefits, many people find it hard to get moving. Even when our patients know intellectually that they need to move more, they still often say things like, “But I just can’t make myself do it” or “I’ve been meaning to do it.” It can be even harder for depressed people, because depression dials down self-motivation. How to pull the sitter off the couch has been a top challenge in our medical practices. Here’s what we’ve found works:

Movement Rules for Brain Health

  1. Move green. Walking outside, preferably in parks, forests, golf courses, and so on, is most likely to generate the quickest feelgood effect.
  2. Move wet.
  3. Move fast to feel better fast.
  4. Move together. Having an exercise buddy keeps you both accountable.
  5. Move techie style. Your exercise buddy can challenge you: “How many steps did your step counter record yesterday?”
  6. Visualize what smart medicines you are making in your body and brain. Ponder the mover-versus-sitter figures on page 101. Imagine: “That’s really going on in my body and brain. My beautiful pharmacy inside is making just what I need.”

Our closing “prescription” for brain health: Go outside and play!

Excerpted from The Healthy Brain Book (BenBella Books).