Go Swimming/Jog or Hit the gym and lift weights. That really really helps to battle stress for me, or any other similar sport.
From the ones i mentioned ,in my experience, swimming is like the best against stress it's like you ''wash away'' the stress, they all do wonders and are very close to each other but swimming's the best (again IMO).
Any kind of activity be it aerobic or anaerobic will work, it's like in ''in your face'' for lack of a better word. Most if not all the stress in your body/muscles will go... eventually.