Once the race is underway, think pacing and overall goals. Remember what you set out to do and monitor yourself so you have the greatest chance to succeed. You will no doubt be buoyed by the energy of the runners around you and of the spectators along the course. Tap into it and let it carry you along, but don't get overzealous and run too fast at first.

Here's where reinforcing self-talk can come in handy, too. Turn your focus inward and remind yourself why you're running. Congratulate yourself for being in the marathon, for realizing your goals, and for being in good health.

For example, a first-time marathoner reminded herself at every mile marker along the way of two different things she was grateful for. Reminding herself of her many blessings became an ongoing way of staying motivated and positive. If you think it might be difficult to come up with 52 things (plus a few more when you cross the finish line!), think again—or re-examine your life. Doesn't it feel good to be alive, good to be in an actual race, geared up to run 26.2 miles? Relish the journey!

If you've never run a marathon, there is no way to fully understand in advance the special feelings you will experience during the event. Savor and enjoy each and every moment. Take in all the sights and sounds along the way.

High-five the extended hand of a child who views you as an athlete competing at center court. Smile at the spectator who tells you, “You're looking strong.” Offer some brief words of encouragement to a fellow runner who may not be feeling as strong as you are. Enjoy the diverse scenery along the race course, whether from a bridge you cross, a hill affording a panoramic view of the countryside, or at the sight of storefronts while you cruise down Main Street.

Along with the accomplishment of a goal you've worked so hard to achieve, you will be creating memories.