Paul Tholey wrote a paper which explores muscle memory learning in LD's. The brain is still sending move messages in your LD (which is why your eyes move and you may twitch) but your in sleep paralysis. You can practice your martial arts at the Lucid Dojo.

For my own part my brain is now convinced I can do a punch front somersault... well I tried it, my brain might have the skills but my body does not have the strength/skill..