I thought this was only me, but then someone else posted that it happens to him too, so I'm opening it up to a larger audience.
Ever since I started to train seriously, I often twitch as I'm relaxing into sleep. It's not painful, and it's not even uncomfortable but it's odd: I'll be relaxing, nearing sleep and then various muscles will suddenly jerk. I figured this was just part of the recovery process and since it doesn't happen TOO much have simply been ignoring it. But now I wonder if it's a signal I'm not getting enough of a particular nutrient or that I'm doing something I shouldn't (or not doing something I should). I'm somewhat older --48 -- but in good health.
Does this happen to anyone else? And for you with more experience than I in training (which is most of you) -- is this something to be concerned about/should I be doing anything about it?