pediatric housecalls Robert R. Jarrett M.D. M.B.A. FAAP

Worlds Most Massive Study: Five Diseases Reduced by Physical Activity, Excersize

April 7, 2019

Believe it or not, the absurdly-expansive claim about exercise in the heading even may be an understatement! No other study even comes close and it’s findings were unexpectedly clear: FIVE OF THE WORLDS TOP DISEASES ARE REDUCED BY PHYSICAL ACTIVITY. Simple physical activity!

Literally, the counsel given to Adam and Eve: “by the sweat of thy brow thou shall eat thy bread” seems to have been a commandment and not just gardening instructions!
Sitting is the new smoking: fitness habits for life
Massively increased computing power has now given us the ability to merge the many good individual studies about disease and activity levels into one gigantic study where the statistics can actually become meaningfully predictive.

Doctors at the University of Washington in Seattle have done just that, merged 174 studies into one and come up with—are you ready for this—149 MILLION 194 THOUSAND and 285 PERSON-YEARS of followup to prove that regular daily activity really does lower the risk for: Breast Cancer, Colon Cancer, Diabetes, Ischemic Heart Disease and Ischemic Stroke.

Did you get that? 149,184,285 person-YEARS. Person-year, that’s following one person for a FULL YEAR. Following 20 people for that long is twenty person-years. So is following one person for 20 years; which, obviously, is what is needed to prove that someone is not going to get a disease like diabetes.

Their report was published in August in the British Medical Journal which told how they combined the studies and the measurements they used and how they concluded that: the more total regular daily physical activity one engages in the lower the risks for breast cancer, colon cancer, diabetes, ischemic heart disease, and ischemic stroke.

And it was not just treadmill-type exercise it included: recreation, transportation, occupational activity and even daily chores!

More Than WHO Recommendations
Greater than 600 METS up to 3000

For several years now the World Health Organization (WHO) has recommended adding 600 METS of exercise each week to stay fit and loose weight; but that, it appears, is not enough.

METs and Exercise

What’s a MET? It’s a measurement of YOUR body’s expenditure of energy for any given task; and is based on two known facts: 1 – that your expenditure is different than someone half-your size, and; 2 – energy used is directly related to oxygen used.

If you put YOUR body in a bed, completely at rest, and measure how much oxygen you use—that’s 1 MET. If you then vacuum for a minute and find that you use twice as much as when you were sitting—that’s 2 METs. Do that for a minute and it’s 2 MET-minutes, do it for an hour and it’s 2 MET-hours. Get it?

So, when the WHO say’s ADD 600 MET-minutes a week, that equates to about 150 minutes of brisk walking (walking = 4 METs per minute) or 75 minutes of running (running = 8 METs per minute) in the week. And because it’s a week measure you can divide up the walking and running between the days.

Adding exercise five days a week, with weekends off, that means walking 30 minutes or running 15 minutes — doable for even busy people.

Problem: not everybody is starting from the same place on the activity scale and it sort of ignores all the activity you do in chores/work/play on a normal basis—or don’t do. So, to start everybody on the same playing field, this study did NOT ignore chores etc. and instead gives you a chance to make normal chores a chance for exercise.

When you do that you find that the benefits against 5 diseases really do occur but at a higher number than previous recommendations—up to 3,000-4,000 met/minutes per week.

And lest you think that’s too much to ask, “a person can achieve 3000 MET minutes/week by incorporating different types of physical activity into the daily routine — for example, climbing stairs 10 minutes, vacuuming 15 minutes, gardening 20 minutes, running 20 minutes, and walking or cycling for transportation 25 minutes on a daily basis would together achieve about 3000 MET minutes a week.”

How much of that are you already doing each day?

If you’d like to tally all your activities there is a chart available for the common activities in people’s lives. Compendium of physical activities: https://sites.google.com/site/compendiumofphysicalactivities/ – The latest is from 2011. It’s a full compendium, available by slecting “compendia” tab and scrolling down to “2011 compendium (complete)”

Reaping Benefits of Exercise

A person sitting quietly in a chair without moving for a minute uses 3.5 milliliters of oxygen per kilogram of body weight. That, as we’ve said above, is one MET-minute. And, when you tally all the millions of people on the earth that they studied, you find that the closer you get to 3-4,000 MET-minutes a week the less Breast Cancer, Colon Cancer, Diabetes, Ischemic Heart Disease and Ischemic Stroke you see in those people. Significantly less.

Of course, any physical activity is better than none and the good thing is that this study does bear that out too. The study shows that there is a “dose relationship” between exercise and the risk of those 5 diseases for amounts between 600 MET-minutes per week and 3-4,000—just not as much.

And remember, this amount counts turning household and daily chores into exercise.

A “Dose” of Exercise

This study is very important because it’s the very first to put actual numbers to the relationship between total physical activity across all domains of life and the risk of five specific chronic diseases.

The 174 prospective cohort studies included 35 studies for breast cancer, 19 for colon cancer, 55 for diabetes, 43 for ischemic heart disease and 26 for ischemic stroke.

If any single study didn’t record their outcome in METs, the researchers went back to original records and painstakingly converted the activity into estimated METs.

What did they find? The higher the total physical activity the lower the risk – FOR ALL FIVE DISEASES!

For example: In diabetes, only 600 METs per week compared with no activity gave a 2% lower risk. If METs per week jumped to 3600 there was a 21% lower risk. Exercise above that (up to 9-12,000 METs) yielded only an additional 0.6% reduction.

If you get less than 600 MET-minutes per week you are considered “insufficiently-active.” Greater than 8000 per week is considered “highly-active.”

Comparing insufficiently-active with highly-active gave substantial and surprising results: Breast cancer, down 14%; colon cancer, down 21%; diabetes, down 28%; ischemic heart disease, down 25% and ischemic stroke, down 26%.

Other Studies and Future

The message of these results is that activity level is not the only factor in these five diseases but is now proven to be a significant one without equivocation.

Another, unrelated, meta-analysis study of more than a million patients revealed that an hour of moderate-intensity (4 METs per minute) activity, like brisk walking or cycling, will offset the health risk of 8 hours of sitting.

So, sitting is the new smoking I guess. And these days we’ve got pedometers and accelerometers available to help calculate our MET activity on a daily basis.

The 5.3 million premature deaths per year worldwide is as much as caused by smoking and twice as much attributed to obesity.

The promising thing about it is that ANY amount of exercise is better than none and getting 3,000 METs is doable by almost everyone physically able.