I had a Doctor friend that told me that women were not built for hard labor, they just didn't have the build. He cited a woman who worked on an assembly line and continually came in to see him with joint paint and muscular problems.. Conversely, there are some men who are not built for hard labor, it takes its toll regardless of whether it is a man or woman and heredity also plays a role. I guess the end result is in the end all of us hurt with hard labor.