yes, it IS because you smoke weed, but it's not something to worry about. it happens to me a lot when i start jogging a lot, or working my legs out. it's just your muscles responding to the cannabis effects, and more than likely the twitching is a result of them relaxing.

when i start jogging a lot, my leg muscles get tighter and firm, and when i smoke it seems they have to struggle to relax.. hence the twitching.

when i was a brand new smoker it happened to me regardless of my physical activity. perhaps you are a newer smoker and your body is just getting used to it.

either way, there is nothing wrong with you :stoned: