What exercise would help me pull my bow better?

I do competitive Archery (recurve bow) and i am having difficulty pulling my bow as i am shaking a lot when i shoot. i do not have a very high poundage but in order to shoot a longer distance i have to get a higher poundage so i have to overcome my problem of shaking and having not enough strength to pull my bow. Any suggestion on what kind of exercise i should do?