I have been running in Vibrams now for quite a while (up to 8 miles at a time, at a 8:20 pace). It is almost completely painless when I don't run on roads. However, when I do, my feet hurt as though I have been standing all day or walking all day. Will this go away?
No, it will not go away. Unless you do something about it.
Since you've been running in Vibrams for "quite a while" your feet should have adapted by now, and you should be able to run without pain in your feet.
The muscles in your feet should have gained enough strength after 4-8 weeks. The joints, connective tissue, and tendons might well take longer; ½-1 year before they've adapted fully.
So if "quite a while" means a year or more then the pain in your feet will not just go away, and you'll have to change something in order to get a different result.
What you could/should do:
- See a doctor, physio therapist, or the like, and let him examine your feet. Don't just trust the advice of some people you asked on the internet - maybe they want to do you harm, maybe they're ignorant, and they've probably never even seen your feet, so how can they give you advice on them :-)
- Try giving your feet a running break for a week or two, and then start up gently. The pain could just be your feet trying to tell you that they can't keep up with your running ambitions.
- Try another model of Vibrams. Making Vibrams is a complex task, much more complex than making regular running shoes, since feet are so different and Vibrams have to fit really well in order to support your natural barefoot feeling. And since it's so complex to create fitting Vibrams, it's a complex task to select the right ones too. You might well have chosen a wrong model. A specialized store with running shoes should be able to give you advice.
Barefoot running should not hurt your feet, but if it does (for an extended period of time), then something is wrong and has to be corrected. Good luck with it.