Age Wise

The Evolutionary Evidence for Getting Off Your Butt

Unlike apes, we evolved to need physical activity into old age

Robert Roy Britt
Published in
5 min readNov 23, 2021


Image: Pixabay/Thomas Skirde

Some food for thought as you laze about during the holidays: As you get older, you might naturally think you should take it easy, be less physically active to protect your precious body. Exactly the opposite is true, according to a new hypothesis that aims to explain how and why humans evolved to live so long and what evolution expects us to do about it in order to stay healthy.

Unlike the apes in our family tree, we humans evolved to be quite physically active, especially as we age, according to a new hypothesis.

Moderate physical activity throughout life, and particularly later on, is a key to the comparatively long human lifespan and also the so-called healthspan, the years we live in good health, a team of evolutionary biologists and biomedical researchers argue. Whether running from tigers, hiking for miles to fetch water, or simply heading out for a nice brisk walk after an outsized meal, physical activity directs the body’s energy into slowing the aging process and protecting us against debilitating and deadly diseases.

“It’s a widespread idea in Western societies that as we get older, it’s normal to slow down, do less, and retire,” says the team’s leader, Harvard evolutionary biologist and paleoanthropologist Daniel E. Lieberman, PhD. “Our message is the reverse: As we get older, it becomes even more important to stay physically active.”

The new hypothesis, published this week in the Proceedings of the National Academy of Sciences, is rooted in three lines of strong evidence.

1. Your ancestors did it

For starters, people in hunter-gatherer societies that exist today typically get more than two hours of moderate to vigorous physical activity on a daily basis — more than six times the effort of the average American.

Lieberman has seen this sort of activity first-hand, studying hunter-gatherers around the world. As one example, people in the well-studied Hadza tribe of Tanzania typically walk five to 10 miles a day for food and water.



Robert Roy Britt

Editor of Aha! and Wise & Well on Medium + the Writer's Guide at Author of Make Sleep Your Superpower: