First off, let me be the first to welcome you to the booth, Lindsey!
Secondly, some disclosure. I am not a rigger of the up or down variety. But I do know my way around a fly
system, including a stint last summer working for the rigging company who installed our new fly
system, so I know just enough to be dangerous. But everyone's experience is different, take my thoughts for a grain of salt, blah blah blah.
Thirdly, my thoughts. The most physical discomfort that I experienced in my time working for the rigging company was in my lower back and shoulders. My lower back was primarily due to all the time I spent in the
grid either crouching or on my knees, which took my legs (my strongest muscle group by far) entirely out of the picture. So I would say that you can never do too much to focus on your back in general. If you have access to any of the P90X videos, I've found that the Legs & Back video is spectacular for working your legs in a way that ties them into your back and core. And my shoulder soreness, that was due to the fact that we were continuously moving lead bricks up and down 16 flights of stairs. For that, I would try to avoid gigs that involve moving lead bricks up and down 16 flights of stairs. In all seriousness though, I've seen more than a few shoulder injuries due to guys trying to muscle stuff up, so it's another area to watch.
And finally, a thought that I'm sure you're no stranger to, but sometimes it's nice for everyone, man and woman, to hear again. Know your physical limitations, and don't be afraid to defend them. I know what it's like to be pushing cases and have some meathead try to take an amp away from you because they think you're a delicate little flower. I've had to take more than a few cases back from aforementioned (and usually well-intentioned) meathead and say, "Dude, I got it, go get your own box." I know what it's like to want to prove that your gender isn't a liability. I get it. But I also know that our careers will only last as long as our bodies do, and my career isn't worth sacrificing for the sake of my pride. There is ZERO shame in asking for some extra hands when you know that something is heavier or more awkward than you can handle. Pull your weight,
throw down, and be the first one to dive in, (as I'm sure you do,) but also know what you can and can't physically handle and protect your most valuable asset: you.