Well, it looks like women have been balancing a full-time job and motherhood for thousands of years. All the while, they haven't gotten much credit for it.

By studying the bones of ancient women in Europe, archaeologists at the University of Cambridge have uncovered a hidden history of women's manual labor, from the early days of farming about 7,500 years ago up until about 2,000 years ago.

"Hours and hours of manual labor that provided the driving force for the expansion of agricultural economies and innovation," says Alison Macintosh, an archaeologist at the University of Cambridge, who led the study.

She and her colleagues found that prehistoric women had incredibly strong upper bodies during the early days of farming. On average, their humerus bones — the upper arm bone — were about 16 percent stronger than elite rowers today, who work their arms intensely for 18 to 20 hours each week.