Get up and move. It may make you happier.
Of course, this type of study does not establish causation. It cannot tell us whether being more active actually causes us to become happier or, conversely, whether being happy causes us to move more. It only shows that more activity goes hand-in-hand with greater happiness.
I’m not sure if it’s the walking that’s making me happy, or seeing my Fitbit’s step count climb to first place on the leaderboard.