Sometimes you just need a simple verb: run, walk, sit, stand. Simple verbs are the workhorses of your prose. Use them when the action doesn't matter much.
Action verbs move your story forward and add definition to the movement.
It may seem arty to have your characters sit, smoke, drink coffee and chat. Please, I beg of you, don't make it the entire chapter. Their conversation should be tense and informative too.
Weak or simplistic verbs convey action but do not add further information. A verb that you had to modify with an adverb isn't a strong verb.
Weak: Sally ran fast.
Stronger: Sally sprinted.
Stronger: Dick tiptoed into the room.
Stronger: Jane slammed the ball with the bat.
Sitting, standing, running, jumping, sighing, weeping, and laughing are all fine when used moderately.