There you sit in front of your computer, or maybe you're reading on your phone. You could be at work or in the passenger's seat of a car — or you may even be working out! I don't know your life. But one thing's for certain: however you're reading this, you are definitely not working as hard as a prehistoric woman.
A study published in November 2017 in the journal Science Advances compares the skeletal remains of modern women to those from the Neolithic, Bronze and Middle Ages in central Europe, and finds there are probably few, if any, elite female athletes alive today whose arm strength compares to the average prehistoric female farmer who lived 5,000 years ago.
Previous studies comparing the bones of prehistoric people to those living today have focused on the bones of men, which is typical, but makes a bit of sense in this case because men's bones are easier to "read." Bones are made of living tissue that responds to the amount of physical work we do, but since a woman's bones also give up minerals during pregnancy and lactation, it's a little more difficult to make clear-cut assumptions about how much work a woman is doing, or has done, simply by taking a CT scan of her bone.
Be that as it may, repeated strain changes things like shape, curvature, thickness and density of bones over time, and when the researchers compared leg bones of ancient women to those living today, the difference was variable — some had the tibias of a modern ultramarathon runner while others were pretty indistinguishable from those of a 21st-century couch potato. The really remarkable difference is in the arms.
The research team, based at the University of Cambridge, found that the closest modern comparison that could be made to the arm strength of the average prehistoric female farmer was a competitive rower in her mid-20s with a grueling training schedule. Rowing is not only strenuous, it's unbelievably repetitive, and although the researchers can only guess at what Neolithic and Bronze Age women were doing with their arms to make them between 9 and 16 percent stronger than the fittest rower in the Cambridge University Women's Boat Club, they have a few guesses.
"A major activity in early agriculture was converting grain into flour, and this was likely performed by women," said lead author Alison Macintosh of Cambridge University's department of archaeology, in a press release. "For millennia, grain would have been ground by hand between two large stones called a saddle quern. In the few remaining societies that still use saddle querns, women grind grain for up to five hours a day. The repetitive arm action of grinding these stones together for hours may have loaded women's arm bones in a similar way to the laborious back-and-forth motion of rowing."
But these women's arm workouts probably didn't begin and end with a single repetitive activity. Remember, the plow hadn't been invented yet, and they were most likely the ones responsible for tilling, planting and harvesting crops. They also probably milked and slaughtered livestock, cured hides and made wool into textiles. They were no slouches, these prehistoric ladies.
"The variation in bone loading found in prehistoric women suggests that a wide range of behaviours were occurring during early agriculture. In fact, we believe it may be the wide variety of women's work that in part makes it so difficult to identify signatures of any one specific behaviour from their bones," said Macintosh.