Where I work, primarily younger and stronger men do the heavy lifting warehouse work. The women and older less physically capable older men do the merchandising work.

Now while the heavy lifting work is more difficult on the surface, they don't have to to an overnight shift once a fortnight for range changes, like the merchandising staff do.

To my knowledge they are both paid the same, but that's never been an issue, as they accept the limitations of there body's and job role.

I for example had to get a heavy item from the warehouse yesterday, and while I am a man, I am also a midget at only 5'7. And because said item was stacked higher than I can reach, I had to ask one of the warehouse guys for help.