“JUST DO IT”- NOT

“JUST DO IT”- NOT

“JUST DO IT”- NOT

An article in the Harvard Journal, written by Jonathan Shaw and titled “Born to Rest,” caught my attention.  I have often heard the phrase “born to run” but never “born to rest.” The article highlights the work of evolutionary biologist Daniel Lieberman on our competing needs to exercise and to rest, and it shines a bright light on why it is often so difficult to motivate ourselves and others to exercise.

Before we became modern humans, we were hunter-gathers.  Food was often scarce, and calories were in short supply.  This required individuals to travel great distances, either running or walking, to hunt and gather food.  If they didn’t engage in this mandatory exercise, they would go hungry and starve to death.  There was no need for nature to build in a desire to exercise since hunger was a strong enough driving force.  Kalahari bushmen still travel up to 10 miles per day in their quest for food. 

Since calories were limited, it was wise to rest as much as possible to conserve energy.  This need to rest was built into our biology and is still with us today.  As Lieberman states, “It is natural and normal to be physically lazy.”  (Yes! normal to be lazy!)  Evolution has made some changes in our foot anatomy to make us better runners, and our sweating system has made us the best endurance animals on the planet.  However, at the same time, nature tells us not to run or walk any more than necessary to get food.  Perhaps we were born to run – but as little as possible.

Muscle tissue is expensive to maintain.  It uses about 25% of daily calories.  Nature does not want us to have big muscles.  Muscle wasting from disuse evolved as an adaptive mechanism that lowers energy consumption, whenever physical activity is not required.  Quoting from the article, “And exercise itself stands against two million years of human evolution screaming, “Don’t do it!” (Nike…take note.)   When people say they don’t need to exercise, don’t like it, or it seems foreign to them, they have nature on their side.

Now we are in modern times and still have the same biology of the hunter-gathers of millions of years ago.  The same two competing mandates continue to operate: exercise only as much as necessary to get food and rest as much as possible to conserve calories.  Nature did not anticipate a time when calories were no longer in short supply for most people.  Today we can go to Wegmans for one hour and get enough food for the week. Then, we can rest the remainder of the week with no immediate consequences.  The result is an epidemic of obesity and all the medical problems caused by it.  The statistics are staggering forty percent of women, thirty-five percent of men, and seventeen percent of children are obese in the US.

We often set up an artificial belief system in order to motivate ourselves to exercise.  This way the exercise has a purpose.  Various goals might include: I must run to prepare for the next race; I must exercise to lose weight; I must exercise to stay healthy; I have to get in shape before the class reunion; I will participate in a fun activity today.  Without these artificial self-imposed mandates, we fall back into being what nature intended us to be:  animals who exercise only when necessary and rest as much as possible.   We are indeed, “born to rest.”