I've written before about the laundry list of reasons that sitting for long periods of time can be really, really bad for you.

Like studies that show sitting all day won't just make you fatter, it can also make you dumber. Or that when you sit for the majority of the day, your risk of cardiovascular disease doubles compared to people who stand. Or that if you sit for more than six hours a day you could be 18 percent more likely to die from diabetes, heart disease, and obesity than people who sit less than three hours a day.

Or that -- and this one is literally a killer -- if you sit for more than 11 hours a day, you could be up to 40 percent more likely to die in the next three years compared to people who sit for less than four hours.

Yep: Sitting is really, really bad for you.

Kind of.

According to Daniel Lieberman, Harvard biology professor and the author of my new favorite book, Exercised: Why Something We Never Evolved to Do Is Healthy and Rewarding, sitting isn't a new by-product of the knowledge work age. 

Lieberman spent considerable time with indigenous hunter-gatherers in Latin America. One goal was to determine how much time those individuals spent lifting, carrying, walking, running... and sitting. 

Contrary to what you might imagine, go to the average village in a remote part of the world and you'll likely find most of the people sitting. In fact, the average hunter-gather sits approximately 10 hours per day. And they, like our ancestors, tend to get in about five miles of walking. 

Which is exactly what you'll find if you go to the average American home or office.

How can you reconcile the science that claims sitting is the new smoking with the fact that for centuries the vast majority of people, regardless of geographic location or profession or lifestyle, have spent much of their day sitting?

According to Lieberman, the problem doesn't lie with the time we spend sitting while working. When you look at how much leisure time sitting we do, that's when the outcomes get scary.

Why? Think about how you work. Even though you may be sitting, you're constantly in motion. Reaching. Shifting. Fidgeting. Pacing while on the phone. Getting up to refill your water bottle. To use the restroom. To look outside to relieve the boredom.

Even though you're sitting, you're at the very least micro-moving (a term I just made up).

Compare that to leisure time sitting. Say you've decided to watch The Queen's Gambit. You grab a drink, grab a snack, grab a blanket, and settle back into a comfy couch or chair. 

And you hardly move. Because that's the point of chilling.

As Lieberman writes:

When we squat, periodically stand, do light activities... we contract muscles throughout the body, setting in motion their cellular machinery. These light activities stimulate muscle cells to consume energy, turn on and off genes, and perform other functions.

These activities aren't serious exercise, but experiments that ask people to interrupt long periods of sitting even briefly -- for example, just a hundred seconds every half hour -- result in lower levels of sugar, fat, and so-called bad cholesterol in their blood ... and stimulate muscles to quench inflammation and reduce physiological stress.

So what should you do?

First, stay conscious of how much you sit at work. Whenever possible, move around. Stand when you use the phone. Stand for a Zoom call. Use choice architecture to create reasons to get out of your seat. Keep water, snacks, etc. in another room. Set a timer to remind you to get up every 30 minutes. Take a brief walk at lunchtime.

Those (literal) steps, combined with the moving and fidgeting you naturally do as you work, should be plenty.

Then focus on being more active during leisure time sitting. Instead of totally vegging, find ways to occasionally move. Play with the dog. Fold laundry. Just changing positions frequently will help.

Or use that time to do things you often don't manage to get around to. Since I think stretching is really boring, when we watch TV I get on the floor for 15 minutes and work on my flexibility. (As well as any core work I haven't done that day, since core work is my favorite exercise to find an excuse not to do.)

As Lieberman writes, "It bears repeating that the scary statistics we read about sitting are primarily driven by how much we sit when not at work."

So where avoiding the harmful effects of sitting are concerned, make that your focus.

Science says so.