Without a doubt, the easiest way to avoid a crash after the post-race high is to pick a new goal. Decide what you want to tackle next -- whether it's getting faster, going further, being more consistent with your training, trying complimentary workouts, or maybe even setting your sights on a different sport altogether -- and put a plan together for how you'll go about achieving it.
I'd been trim all my life. I had two kids and proudly fit right back into my size eights after the birth of each one. Somehow, 20 years of life, and stress, sickness, and eating, found its way onto my five foot two inch frame. Although it certainly didn't happen overnight, it felt like I just blinked and there were a hundred extra pounds to be found inside my clothes.
Like most new physical endurance based challenges, running is going to be something you will most likely fail at miserably on the first try. You will lace up your shoes, head out the door, and three minutes in, lungs burning and heart pounding, your mind will begin tossing out questions: "Isn't this supposed to be fun? When does it get easy? Where's the runner's high? When will I be able to talk? What it so darn great about running? I just want to stop and lay down!"