The purpose of exercise is not weight loss, looking hot or ’six-pack abs’.


Yes it’s true that all the things just mentioned are associated with exercise but they’re the favourable side effects of exercise and not the purpose.

The purpose of exercise, from an evolutionary perspective, is to prime the brain for learning.

It’s a proven fact that exercise, particularly aerobic activities like brisk walking, swimming or High Intensity Interval Training; the stuff that makes you ‘huff and puff’, causes the brain to produce BDNF: brain derived neurotrophic factor.

And what the heck is BDNF?

In non-technical terms, John Ratey MD calls BDNF the ‘miracle grow for the brain’.

READ THIS: John Ratey has written two remarkable books on exercise and brain health, ‘Spark’ and ‘Go Wild’. Buy them from our Online Shop.

Technically, BDNF is a protein made by the brain to help existing neurons survive and new neurons grow.

Mice born without BDNF suffer developmental defects and while it’s true that most of the neurons in the human brain are made prenatally, there are parts of the adult brain that retain the ability to grow new neurons in a process called neurogenesis.

Importantly, the ability to sustain and grow neurons is a REALLY BIG DEAL! And what does exercise help the brain do well?  You got it! Make BDNF.

Just 20-40 minutes of aerobic activity can increase BDNF in the blood stream by 30%.

“And then what happens?”

I’m so glad you asked.

All manner of good things. Study after study consistently makes the connection between exercise and positive effects on all things brain related:

  • reduced anxiety and improved stress coping
  • enhanced cognitive control of behaviour
  • lessen negative effects of mental illness and behavioural disorders
  • improved academic performance in children, adolescents and adults (Yep! Fit people are smarter people.)
  • improved productivity
  • and preserving cognitive function in old age.

TRY THIS: Want to find out for yourself what happens to your brain and emotional health after daily exercise? Track it!

Download a free PDF here: 19-dailymoodchart. Or grab a Mood Tracker bullet journal for 2019 to get serious!

But why does all of this good stuff happen just from moving your body with a purpose?

It’s argued that the primary reason for a brain, any brain, but also the primary reason why the human brain is so big, is to perform complex and adaptable movements. That’s it!

The purpose of a brain is not mathematics it’s movement.

BRAIN FACTS: Big brains = more complex movements. Size is not the only measure of a brains ability to perform complexity movement but it is one measure. Our 1.2kg human brain is beat by dolphins (1.5-1.7kg), Elephants and Blue Whales (5kg) Killer Whales (6kg) and Sperm Whales (7kg).

In other blogs I’ll return to the relationship between having a brain and movement, but for now what you need to know is that when the human body moves aerobically, the movement itself alerts the body that something important is happening; something worth paying attention to, remembering or learning.

Like finding shelter, catching or avoiding a predator, learning a valuable skill, or remembering a trail so you can return to a useful food source later or not get lost.

The equation goes like this:

Aerobic Movement = important stuff is about happening = increased BDNF release = best opportunity to learn.

The opposite is also true.

The science that gives us the alarming phrase ‘sitting is the new smoking’ has linked sedentary behaviour with actual physical changes in the brain; specifically, the thinning of the medial temporal lobe, a brain region involved in the formation of new memories.

Brain ‘thinning’ is a big deal because it can be a precursor to cognitive decline and dementia in middle-age and older adults.

With this revelatory fact in mind, the discovery of brain thinning puts a very different spin on the cause of the massive increase in the diagnosis of alzhiemers and dementia sufferers. It’s not simply a statistical reality of an aging population; it also appears to be caused by an aging sedentary population!

So my big ‘take-away’ for you is this:

Forget weight loss and ‘six-pack’ abs, the primary purpose of exercise and physical activity is first and foremost about BRAIN HEATH.

The second and third, fourth, fifth and sixth benefits of exercise are all the other wonderful things that flow from exercise.

One question quickly emerges from this discussion is how much exercise and of what kind.

I’ve discussed the ‘how much and what kind’ question in an earlier blog but as a summary:

#1: AEROBIC. Exercise four days a week, varying from thirty minutes to an hour, at 60% to 65% of your maximum heart rate.

#2: STRENGTH. Use weights or do resistance training twice a week – three sets of an exercises using weights that allow you to perform ten to fifteen repetitions in each set is great.

#3: BALANCE AND FLEXIBILITY. Twice a week for thirty minutes or so: yoga, pilates, tai chi, whole-body movement (Rewilding) martial arts, and dance all involve performing skills that keep us flexible and agile.

#4: VARIETY & NEW LEARNING. Do a mix of low, medium, and high intensity exercise and be sure to learn and try new movements and activities that challenge your movement patterns and make you feel like you have two left feet! Variety is a rocket fuel for the brain and body.

#5: DO IT IN NATURE. At some point I’m going write about biophilia and the MASSIVE scientifically demonstrated benefits of doing movement training and exercise in nature, but for now just take my word for it:

Humans are mammals and we have a greater genetic and evolutionary connection with oceans and trees than with UV lights and treadmills. Get outside!

So if I offered you a pill that you could take every morning on the promise that it would reduce your anxiety and stress, improve your mood and motivation, increase your ability to learn and make you the best version of yourself for the remainder of the day, would you take it!

Oh come on you’d take two!

Well such a miracle ‘drug’ exists only it’s not a pill and it won’t cost you a cent.

It’s exercise!

Go on, do it for your BRAIN!


Here’s a cool TEDx video on this very subject” “The Brain Changing Effects of Exercise.”

— Damien Norris is the senior whole-body movement and lifestyle coach at The Wilding Project (LINK), Perth Western Australia. Recently featured in TEDxPerth (LINK), Damien teaches children, young people, adults and seniors how to move and live a full life! Olympic Fun & Fitness and The Wilding Project like Rewilding is dedicated to a movement rich life. Programs like Gymnastics, GymFIT, FootyEDGE, Parkour, Workplace Athletes, Active Agers and more all follow a simple philosophy, “Learn to move well and then never stop.”