Something people underestimate (I think) is that having a correct posture requires having strong enough support muscles so that you can maintain said posture without getting tired, or even thinking about it. By far the biggest benefit of going to the gym has been that my core muscles got stronger, which in turn has cured all back pains I had.
Thanks for saying this - another reminder to do more core (got down and planked). What exercises did you find most beneficial for strengthening? On a related note -- I periodically do stretches where I stand on one leg and roll my hip & waist out to the side extending it behind me -- that helps alleviate tension in the side. Similar - hanging on my forearms from chairs or those ab machines at the gym. Pain Free (a me…
Mark rippetoe's book on starting strength is a great read on how to execute compound barbell exercises like the deadlift, and also has some great information on things like progressive overload. I'd recommend it even if you don't plan on following the starting strength program.