Physical Activity vs Exercise: Round 2

In Round 1, I acknowledged the strong influence that NON-exercise physical activity (PA) can have on our health and longevity.  In Round 2, I'll describe a few advantages that exercise has over PA.

Hinting to these advantages at the end of Round 1, I pointed to a key word within the conclusion of this study:

"The association between prolonged sedentary time and cardiometabolic biomarkers is markedly less pronounced when taking fitness into account."

Fitness, often defined as the quality of being suitable to fulfill a particular role or task, is most easily addressed via exercise.  This is because with exercise, unlike with PA, we are consciously harnessing our bodies' ability to specifically adapt.

Given sufficient time and the appropriate exercise prescription, it's possible to make ourselves FIT enough to do most of the things that we may desire to do.  Which is what gives exercise this first advantage over PA:

A well designed exercise program can yield very specific improvements to one's fitness

Need VERY high "cardio" fitness to counter the effects of your sedentary job?     E X E R C I S E

Need to maintain the strength necessary to carry bags of groceries with ease?     E X E R C I S E

Need to regain joint ranges of motion lost from years of underuse?     E X E R C I S E

Want to gain more muscle mass on certain parts of your body?     E X E R C I S E

Want your body to be able to withstand the rigors of running 26.2 miles?     E X E R C I S E

An exercise program yields these specific improvements via the prescription and imposing of specific stresses onto one's body. This ability to prescribe specifics stresses points to another advantage over PA:

An exercise program can distribute stresses more appropriately onto one's body

Considering our individual differences and the varying severities of wear and tear that we all accumulate over the course of a life, this is a great advantage. If we're smart with our exercise prescription, a proper divvying-up of stresses can prolong the use of an already worn and torn body or better preserve one that hasn't yet been. 

An example may help to better demonstrate this second advantage...

Below is a comparison of the stresses imposed on one's body from building a stone wall (considered here as a form of PA) to that of those imposed from a basic resistance training exercise program. 

To quantify and compare stresses, I'll need to define "work". To do this more easily, I'll simplify the equation for work to be:

Total Weight X Distance Moved in Feet. The resultant value will be "foot pounds of work".

First, building a stone wall: 

BUILDING A STONE WALL

• There are 150 stones. The average weight of each stone is 25 pounds.
• Each stone must be lifted (on average) 3 feet, carried 12, then lowered 1.

• 25 pounds x 16 feet x 150 repetitions = 60,000 foot pounds of work

RESISTANCE TRAINING EXERCISE PROGRAM

Exercise 1 - Deadlift

• For 3 sets of 8 repetitions, 115 pounds is moved a total of 6 feet (lifted & lowered 3 feet)

• 115 pounds x 6 feet x 24 repetitions = 16,560 foot pounds of work

Exercise 2 - Bench Press

• For 3 sets of 10 repetitions, 75 pounds is moved a total of 3 feet (lowered and lifted 1.5 feet)

• 75 pounds x 3 feet x 30 repetitions = 6,750 foot pounds of work

Exercise 3 - Step Up

• For 3 sets of 10 repetitions per leg, 40 pounds is moved a total of 3 feet (lifted and lowered 1.5 feet)

• 40 pounds x 3 feet x 30 repetitions = 3,600 foot pounds x 2 (right and left leg) = 7,200 foot pounds of work

Exercise 4 - Dumbbell Row

• For 3 sets of 10 repetitions per side, 25 pounds is moved a total of 3 feet (lifted and lowered 1.5 feet)

• 25 pounds x 3 feet x 30 repetitions = 2,250 foot pounds x 2 (right and left arm) = 4,500 foot pounds of work

Total work for all exercises = 35,010 foot pounds of work

Notice that the resistance training exercise program (35,010 foot pounds of work) would have to be done twice to match the work of building the stone wall (60,000 foot pounds of work).  For the sake of this comparison, I'll say that the resistance training program was done twice and the wall was built in halves.

With work being held equal, how these efforts differ is in HOW the work was completed. The stress of the resistance training program was spread over four different movements and that of building the stone wall was spread mostly over one similar movement. 

Now, I'm not suggesting that one shouldn't build stone walls in their free time. In fact, I think it's a great idea; they’d be dramatically increasing their PA and enjoying all the nice things that come with building stone walls. 

However, over many years and many walls, the similar pattern of stress and strain would impose a specific pattern of wear and tear. If not managed appropriately, this specific pattern may lead to predictable aches and pains. Ultimately, this could decrease the number of years spent building stone walls. 

So, what I am suggesting is that a well designed exercise program may prolong one's stone wall building years by making them a more efficient and resilient stone wall builder. 

In the third and final Round, I'll point to another common instance where an already physically active person may want to install an exercise program.  This will help to make the case that some combination of both PA and exercise is likely what we should all be aiming for.