Awww...bless it's heart! I have to admit, though....I laughed!!
My cat twitches like that when he sleeps although he doesn't act like he's running. I can tell he's dreaming, though. Sometimes he whines and it's then that I'll wake him up. I don't want him having nightmares!
I do feel like I've run a marathon after supposedly sleeping....maybe I do run in my sleep.....'cos I sure can't when I'm awake!!