Early Thoughts and Beliefs
You hear this a lot …
“Exercise is good for you.”
OR … sometimes …
“Physical Activity is good for you.”
OR … sometimes …
“Being active is good for you.”
No argument there you might say. Pretty obvious you might say. Everybody knows that you might say – however you might feel about exercising, or being “active” (whatever that might mean.)
Anyway the point I am laboring here is that people have been saying this kind of stuff for a looooong time.
In fact, the notion that “Exercise” – or doing some kind of “Physical Activity“ is important to health (“Good for you”) goes back
centuries. Here’s an often quoted example of this …
Speaking generally all parts of the body
which have a function, if used in
moderation and exercised in labors to which
each is accustomed, becomes thereby healthy
and well developed, and age slowly:
but if left unused and left idle, they become
liable to disease, defective in growth, and age quickly.
Hippocrates c. 460-377 BC
However, back then, this notion was just … a notion: an assumption – an idea – a belief. There was no science to back it up. Hippocrates was a bright lad, but (as far as anyone knows) he did not conduct any research to support his pretty definitive (and rather wordy) statement.
SIDE NOTE:
Although the terms “Exercise” and “Physical Activity” are often used interchangeably, in Scientific and Research fields they are defined as separate (but linked) concepts. I’ll write more about this in future posts, but here’s a quick explanation.
“Exercise” is something that is done to “get fitter”. In other words to specifically improve things like cardiorespiratory endurance, muscular strength, muscular endurance and/or flexibility.
If you go to the gym – if you go for a workout – if you go for a run – if you stretch – it all comes under the definition of “Exercise”.
“Physical Activity” is any kind of bodily movement. Anything, in fact, that expends energy.
If you do the laundry – if you mow the lawn – if you walk the dog – if you walk to the fridge – it all comes under the definition of “Physical Activity.”
So, from this perspective …
All “Physical Activity” is “Exercise”, but not all “Exercise” is “Physical Activity”. Got it?
To simplify things I will mostly use the all-inclusive term “Physical Activity” for the rest of this piece.
Although “Physical Activity is good for you” was something that many people were told (and even believed) was true, a considerable time passed between the quotable notions of the Greeks and the research findings of the “Geeks”.
We had to wait, in fact, until the early 20th century.
Investigations begin
The first related research on physical activity was conducted in the 1920’s and resulted in two Nobel prizes. However, this work was focused exclusively on what was called “The Physiology of Exercise”.
NOTE: I have used the word “Exercise” here because this was the term used in those two awards.
We had to wait another few decades for the first research efforts to investigate the health benefits of “Physical Activity”.
Principal Investigator
The most notable researcher in this emerging field was Jeremy Morris (1910 – 2009). A Scottish physician who first worked at the Medical Research Council’s Social Medicine Unit in north-west London and, later, at the London School of Hygiene & Tropical Medicine.
Dr Morris was a pioneer of what came to be called behavioral epidemiology. His signature achievement was a series of studies initially published in the early 1950s and continuing for the next several decades. These studies were the first to provide scientific evidence of the centuries old “notion” that being active was beneficial to health (“Good for you”). More importantly, perhaps, it provided evidence that being inactive was detrimental to health (“Bad for you”).
Dr. Morris conducted and published many studies over his career. However, for the purposes of this post I will focus mainly on his two earliest studies which are regarded as classics in the field.
1. The London Transport Bus Study
Many people are familiar with the iconic red London double decker busses. Back in the 1950s these vehicles had a two man crew: a driver and a conductor.
This first study was set up to compare the rates of coronary heart disease between the bus drivers and the bus conductors.
During their work days drivers were constantly inactive – their whole shift was spent sitting. In contrast, the conductors were constantly active – their whole shift was spent walking up and down both decks of the bus, collecting fares. The study found that, as part of their normal work day, conductors ascended and descended 500 to 750 steps per working day.
An article published by the Financial Times in 2009, quotes Dr. Morris as saying
“The drivers were prototypically sedentary, and the conductors were unavoidably active.”
Additionally, the crew members had similar working class backgrounds, identical shift times, and spent that time in the same vehicle. The predominant difference in their lifestyles, therefore, was how active these men were at work.
This was an ideal “real life” situation for a Research-based health comparison.
Results: In brief, Dr. Morris found that conductors had a significantly lower rate of coronary heart disease (CHD) than drivers. Also, when drivers did suffer from CHD it was significantly less severe compared to the drivers.
As Dr. Morris stated in the study
“… there was a striking difference in the heart-attack rate. The drivers of these double-decker buses had substantially more, age for age, than the conductors.”
Dr. Morris published this first study in 1953. It appeared in “The Lancet”, a major medical journal, and was entitled …
“Coronary Heart-Disease and Physical Activity of Work”
The Reaction
It’s hard to believe now, but Dr Morris’s initial findings went down like a lead balloon when they were first made known. Skepticism came even from the scientific and health communities.
The prevailing comments were something like …
“How could just being more active have such an effect?”
“How could just exercise be this good for you? I mean… after all … its only exercise!”
However …
Shortly after this Dr Morris published the results of his second study
2. The Post Office Workers Study
This was similar in concept and design to the Bus Study, but this time Dr. Morris analyzed the work behaviors of what he called “post office employees”. One group were “Postmen” who, back then, collected and delivered the mail by hand and so spent most of their shift walking or cycling. The other group were clerks: office workers who spent most of their shift sitting down.
As with the Bus study, these two groups had similar backgrounds and identical shift times, but one group was constantly active at work, and the other was constantly inactive at work.
Another ideal Research situation for comparison.
As with the Bus Study methodology, Dr. Morris compared the rates of coronary heart disease between the two groups.
The results, according to Dr. Morris were…
“Strikingly similar.”
The active Postmen had significantly fewer heart attacks than the sedentary clerks.
These two elegantly designed studies, involving literally thousands of subjects, provided strong confirmation of Dr Morris hypothesis that physical activity (Yes, “Physical Activity!”) was protective against coronary heart disease. They set the scene for other, similar, studies conducted both by Dr. Morris and a growing number of other researchers in the following years.
Of course all this is accepted knowledge now, but we owe these revelations to an unconventional Scottish scientist pursuing an unthought of – if not unthinkable – hypothesis.
Final Thoughts:
An article published in the Financial Times back in 2009 focused on the work of Dr. Morris and was titled
“The Man who Discovered Exercise”.
Not to be picky, but that’s not really what he did because – as I explained above – his study was, in fact, all about “Physical Activity”.
But loved that title, and it does not diminish the importance of those long ago findings.
“Good for you” evolved from “Notion” to “Known”