Possible, but Not Yet Truely Achieved
I haven't had many LDs and the ones I had weren't as full as I'd have liked them to be, so I'm not speaking from experience. There is scientific evidence to suggest that this is entirely possible. Visualization has been used by many athletes (including myself) to improve muscle memory when one is not able to practice physically.
My friend tried this and said that 90% of the time the practice didn't carry of into real-life. For this to be effective you should have excellent dream recall to where the only distinction between real life memories and ld memories is the knowledge that you are dreaming.
You would also need to be able to "render" an extremely realistic (as in real world physics, appearance, and body strength, size, and other various factors) environment. I'm not sure of the difficulty of this, but I would expect that if the skills of God are readily available in the dream world it could be quite difficult.
If and when I ever get full lucidity (and once I'm done having a crap-load of fun) I am going to try this out. Can't wait! :)