Sitting is killing you!!! That's what the book "Sitting Kills, Moving Heals" would like you to believe. But is it true?
As someone who values reading above almost all activities, it struck at my soul when I heard author Joan Vernikos discuss the dangers of sitting on a STEM TALK podcast. Actually, the podcast was about the effect of gravity on human health - but Dr. Vernikos has taken her experience with gravity and extrapolated that to human health here on Earth.
The podcast was quite interesting and lead me to get her book on the topic: "Sitting Kills, Moving Heals"
I went into this book with very high hopes. Human health is one of my major interests, so I love to find little nuggets that fit into that puzzle. I was hoping to take away 1 or 2 little things that would add up over time.
It wasn't news to me that sitting was considered unhealthy. We've all seen the headlines:
Sitting is the New Smoking!
But was it really as dangerous as smoking. I SAT DOWN to read this book and will give you a very quick overview of my opinions.
1. The book is very long. Not War & Peace long, but Crime & Punishment long. Meaning it's verbose. The main point of the book can be summed up in just the title - Sitting is bad for you. Or more precisely, continuous sitting without any interruption, is bad for you.
But in the author's defense, she has a lot of interesting and useful background information to share. She gives interesting tidbits from her time at NASA and she does back up most of her claims with published data. This is all good stuff, but I personally would have appreciated if the book were outlined as such: This is what we know and what you should do, then here are all the rest of the chapters containing anecdotes and the data to back up the claims.
Of course, this means most people would only read the first chapter, but it also means people would get the most important information up front.
2. I disagree with her findings. Here's why:
a. Most of the data that says sitting is dangerous comes from epidemiological data based on people's "recall" of their behavior. There are so many levels of wrong in this type of study. People's recall is garbage. None of the studies were prospective and none of them can prove causality. In addition, the biggest studies with the best data show marginal effect at best. They show relative risk adjustments. Ugh.
One of the studies cited claimed a 24% increase in colon cancer associated with sitting. The average risk of colon cancer over a lifetime is 4.2% (you can see lifetime cancer stats here) so a 24% risk increase means that instead of a 4.2% lifetime risk, you MAY have a 5.2% risk of colon cancer. Because we can not assign causality and because data is inherently full of error 5.2% and 4.2% are essentially the same.
There were more statistics, but so much goes along with a sedentary lifestyle and the nature of the data makes it essentially useless.
b. Sitting is natural. Animals sit. We sit. Chairs have been around for centuries (a quick wiki search on the history of chairs pulls up chairs from 200 BCE.) The author claims they were shorter in the past. No, they weren't. I spent way more time that I would like to admit looking at historical chair designs and they were essentially the same. They fell about knee height. If any chairs WERE shorter, they likely corresponded with human leg height and shorter humans. But they required the same effort to get in and out of.
The author points out that the opposite of sitting is standing. And that standing is not inherently healthy!
c. The author argues that gravity is more intensive when we stand. Yes, that seems about right. We are constantly adjusting to gravity in all directions when we stand. Standing and moving take muscles, fascia, tendon, bone and neurological input. She claimed that sitting caused less gravitational input because our heads were in a position closer to the ground (we were shorter.) But..... epidemiological data clearly shows a longevity benefit to shorter versus taller people. And....statistically speaking, the distance from standing to sitting is negligible when computing the forces of gravity. So this argument is bunk.
|Did these two die from sitting too much?|
d. Anecdotally - I have found that being "active" does not necessarily mean healthy. My father had a very active job. He walked all day long and got up/down, bent, lifted, pulled, pushed. He never sat down. He worked every day of his life. He was an hourly employee and did not get vacation days. He was an apartment maintenance worker. He never stopped moving. He got Alzheimer's at age 55. He had a litany of other risk factors - but if he had an office job, is she proposing he would have developed Alzheimer's at 35????? In his case, it does not appear that being active was in any way protective.
Does this mean that being active is not important? Absolutely not. And she is correct that once people stop walking or become bed bound, it's over. They pretty much never get up again. It's just not that big a piece of the puzzle. It's a piece, for sure, but not THE piece and certainly not THE thing that is killing us off or decreasing our overall healthspan.
3. Some of the research she discovered regarding growth hormone levels following bedrest and the effects on blood pressure from standing versus moving are interesting. I don't think they are conclusive, but they do open up doors to further questions.
How much sitting is too much?
Sitting without any other movement. Locking yourself indoors all day. Not moving your body at all. Staring at a screen all day. None of these are healthy. But sitting down to enjoy a good book, sitting around with friends, or enjoying a movie now and then are not deadly sins.
Be active - go out and live your life. But you don't need a standing desk. A treadmill desk (OH MY GOD!!!) or any other contraptions to get yourself moving. You don't need to throw out your bed or your chairs. When it comes to human health, there are much bigger fish to fry.
If you want to read Dr. Vernikos' book - do it. She advocates being more active - nothing wrong with that. But read it not for the dangers of sitting. Read it for the interesting tidbits from her life and experience. Read between the lines to see what Dr. Vernikos actually believes - she mentions watching women get together to walk outside her office - a great healthy activity - and she notices their terrible posture. Bingo. She drops these hints throughout the book.
Do not lie in bed all day. Do not glue yourself to a chair. But dig deeper if you want the truth about what is causing your disease and suffering.