This may be the most important thing I can tell you.
When people talk about training for the NYC marathon they often focus on the bridges. And for good reason. There a number of bridges along the route, the two biggest obviously being the Verrazano and the Queensboro/59th Street Bridge, which both span nearly two miles. I can't count the amount of times people advised me to train on the bridges as practice. And I did! (I also commute into the city from Brooklyn on my bike, so the psychology of the bridge, for lack of a better word, has long been familiar to me.) What no one talks about are the long stretches. That's because they look easy on the map and don't contain any really notable hills. Don't be deceived by this.
As I mentioned, the four-mile straightaway that is the Fourth Avenue stretch through Brooklyn is pretty glorious: you are fresh, the crowds are exciting and fun, and you will be so excited and happy and grateful you decided to run this thing. The First Avenue stretch, however, was the hardest, longest, most soul-destroying stretch of running, or anything really, that I have ever done. It did me in.
The first Manhattan portion of the race runs up First Avenue to the Bronx and begins as you come off the long, tough trip over the 59th Street Bridge. You will be on First Avenue from miles 16 to 20, all at a slight incline so that when you come off the Bridge and turn the corner what greets you is the visual of all the thousands of runners shimmering ahead of you for miles and miles. Miles and miles that you also have to run. For those spectators waiting on First, it makes for a great picture. However, mile 16 to 17 also happens to be where the true, hellish exhaustion begins to set in. Depending on your training regime, it's likely you have only run, at the very most, 20 miles, so it's around this point that you will have to start digging deep inside to a place you've maybe never been before.
At that moment, being able to see how far you still have to run, especially if your long training routes decked in and out and overlapped themselves, is a mammoth head fuck that no one ever warns you about. Instead of being able to talk yourself into making it to the next corner (which, starting now, is maybe as far as you think you'll be able to make it), you are confronted with the reality, right there, staring you down like barrel of a very long shotgun, that you literally have to run as far as your eye can see. And then six more miles after that. All the while there will likely be hoards of drunk brunchers yelling their encouragement.
My advice: Before Sunday go stand at the corner of 62nd and First Avenue. Imagine you are more exhausted than you have ever been in your life. Then imagine you are more exhausted than that. Now stare up the length of First—all 67 blocks. Get used to that view. Own it. Finding the determination that it will take to cover this stretch is the reason you are running this marathon.