The Zero Gravity Lesson We Learned from Astronauts

By Roger Landry, MD, MPH

“Houston, we have a problem.”

Up to 70% of us are classified as “sedentary” by the President’s Council on Sports, Fitness, and Nutrition. “Sedentary” means “sitting” or “with little movement.” According to an Institute for Medicine and Public Health poll, Americans spend an average of 56 hours a week staring at a computer screen, riding in a car, or sitting in front of TV. An A.C. Nielsen Co. report tells us the average person spends about 60 hours a week “viewing content across various platforms,” which is more often than not, sitting.

This IS a problem because humans are meant to move … designed to move. For ninety-nine percent of the time, our species has existed … we walked the earth. Our hunter-gatherer and agrarian ancestors moved in order to survive, and moved a lot. We humans are around today because they did, and we have inherited an innate need to move in order for our bodies and brains to function as they should.  

So, when the Apollo astronauts first went into space for more than a day or two, on at least two occasions our American finest … highly screened and trained space athletes … had to be carried out of the recovery helicopters on stretchers. What was going on there? NASA didn’t know then, but we surely know now. It’s zero gravity … weightlessness. You see, if I want to move in space, a flick of the finger can set me in motion and I can float effortlessly to wherever I want to go. No muscle power is needed. My heart, also a muscle, can take a vacation since pumping blood against no resistance is like sipping a Mai Tai in a chaise lounge. Also, our bones aren’t quite as important either so they begin to not need quite as much calcium and become less strong.

The problem is that we earthlings have succeeded in creating our own brand of weightlessness. We had the view that the more progress we made as a society, the more each of us became successful, the less we would have to move. So, we created automobiles, elevators, escalators, people movers, drive-thru’s, TVs, sofas, and computers. We’ve become sedentary, and that takes us away from the basic need to move we inherited and consequently raises our risk for a slew of conditions that I guarantee you will not welcome.

Rather than movement being a core and essential part of our lifestyle, those of us that try to stay healthy now schedule movement, as a workout or exercise. That’s very helpful and definitely can lower our risk, but recent research brings into question whether that’s enough. Exercise Sport Science Review reported on research, which raised the possibility that even if we are among the minority that actually “works out,” prolonged sitting can compromise our health and increase premature mortality risk. I know that is going to come as a shock to many of my friends.