Grinding grain for hours a day gave prehistoric women stronger arms than today's elite female rowers, a study suggests. The discovery points to a "hidden history" of gruelling manual labour performed by women over millennia, say University of Cambridge researchers. The physical demands on prehistoric women may have been underestimated in the past, the study shows. In fact, women's work was a crucial driver of early farming economies.

"This is the first study to actually compare prehistoric female bones to those of living women," said lead researcher, Dr Alison Macintosh. "By interpreting women's bones in a female-specific context we can start to see how intensive, variable and laborious their behaviours were, hinting at a hidden history of women's work over thousands of years."