I plan to start with a hobby game project. So while doing the research about the same, I learnt about two activities mainly of game design & game development. Now this being my first game I am not sure which of these activities will take more time.

Just a little background about myself : I have been programming for nearly 10 years now and am quite adept in C++ and can code decently in Java as well.

I am currently collecting reading material for both game design and development. So my question is, which should I study first : game design or game development? Which of these if learnt first will help in the other activity?