Yesterday I signed up for the Spartan Race in September. Much like the mud run, it is an obstacle course race with lots of mud, and lots of training needed to get ready. This is going to take a lot of hard work, and suddenly by signing up I feel a lot more desire to train for it than I did before. So many things work this same way. It is very easy to say "this year I’ll get in shape" and watch as one thing after another takes a higher priority. It’s much different to say "I am going to lose 5 pounds by November 1st" and subsequently making sure you get there. Simply by signing up, I have changed how I will be approaching my actions over this coming summer.
Declare what you want. By doing so, you change your path. You ensure that steps are taken towards this goal, as opposed to a vague way around it.