An example, I guess:  I'm small, as a lot of females are.  I work with my husband, who is a bit bigger and stronger than me.  Our job requires us to carry a lot of stuff sometimes, and there are many times that someone will see things piled up in my arms and offer to help.  (They don't do that to my husband, I presume because he's male and therefore supposedly better able to perform the job on his own.)  But I refuse; I know what my own limits are.  Just because I may look overwhelmed doesn't mean I am, because I know how to handle myself.  

Maybe this isn't the best example, but I empower myself by proving to myself that I can do this even if everyone else thinks I can't.  Hopefully, this shatters a little of that "women are no good at physical work" myth in other's minds too.

Does that make more sense?

Studying to be a scientist, too, thanks.

I'm not saying women have to work harder.  I'm saying women should do their best and make sure they get credit for it.  If the common thought is that we can't do something because we're female, then all we have to prove is that we can do it, not that we can do it as well or better than anyone else.  So we should focus on those things that we ourselves want to be good at, not the things that everyone else says we should be good at.