I am planning on running my second marathon in the spring and would like some advice given the results of my first marathon. At the first one, my goal was to finish in under 4 hours, and I finished between 4:00 and 4:01. I had been training at around 9 minute/mile pace on my long runs, but it was difficult for me to keep that pace throughout the entire long run (I ran three 20-milers during training). At the race, I went out way too quickly, completing the first half in 1:36. I felt great until about mile 16, at which I could tell my legs were getting tired. Miles 16-20 were difficult, but I kept a decent pace (around 8:30). Miles 20-26.2 were horrible. I slowed considerably to over 10:00 miles, and starting around mile 24 I really cramped up. By the last mile and a half, I had to stop about every twenty or thirty yards to stretch out my legs to keep them from cramping. It was a horrible experience. I would really like to do everything I can to make this second marathon a great experience, and I'd appreciate any advice anyone has--my training starts December 5, but I have been training for a half that I'm going to run in a few weeks here, so I've got a decent mileage base from which to start. Thanks again for any advice!

You did the first half in 1:36? That's way too fast. It's no wonder you were done by mile 20. You'll do fine in the next one but really pay attention to your early pace especially the first 5 miles. If you pace yourself you should be able to cut 10 or 15 minutes off your first one. Good luck

How far did you run on your longest pre-marathon run? I'm a firm believer that you need to get pretty darn close to 26.2. I actually run up to 30 on my longest run, to smash the psychological 26.2 barrier.

When I ran my first sub 4 hour marathon, I carefully followed the advice given by "Four Months to a Four Hour Marathon". The training plan in the book worked perfectly for me. Interestingly, the author suggests doing long slow weekend training rows at 10:30 / 11:10 pace. All of the speed work is done at 8 minutes/mile, and there are other weekly rituals. Many people disparage long runs that aren't at race pace, saying that if you don't train at 9 minute miles, you can't race that fast. I'm proof that they're wrong.

Thanks for the tips so far. To answer your question, I ran three 20 mile runs during my training for the last marathon. I have thought of what you are saying about running a longer distance during training, and I am planning on running one 23 miler in addition to two 20 milers this time around. Do you think I should run longer? Because I want to run the marathon at 9 minute/mile pace (to put me under 4 hours for the race), I am reluctant to run my long runs slower than this, fearing that my body will get adjusted to running slower and I won't be able to run at or under 9 minute/mile pace during the marathon. Can someone describe how it is they are able to run a minute or 1:30 per mile faster during the race than they train during their long runs?

Look at runners splits who finished in 4 hours ,or any time that you would like to finish in. You will see plain as day that the runners who had the slowest first 10k (58min-1:02min) times had the fastest last 10k times (and probably the most fun). Run the beginning of the race as if the race was 100 miles long . Think in your head that the race begins at the 20 mile mark. Good luck
I tried my best in NYC to run 4Hrs. but ran it in 4:09

I typically train at between about 8:30 and 9:30 mile and my marathon pace is 7-7:15/mile. You won't develop yourself aerobically if you always run at close to your race performance level (assuming it is the best you'd be able to do for that distance) and you likely will end up with an overuse injury. If you can get some runs in on hilly courses, just pick up the pace on the downhills and slow down on the ups to maintain steady level of effort and that will give you enough time at higher paces to have you prepared. Also, you can do a few marathon paced runs if you really are concerned about not being used to the pace. It doesn't take many.

Personally, I think 20mls is plenty for the peak long runs but aim for 2~3 of them along with a similar number of 18ml runs. As well as building muscle and teaching your body how to run long distances it'll also build your self-confidence. ie 6x runs @ 18mls+.
1:36 is a very decent time for a Half Marathon or if you're aiming to close and have trained to close a full marathon in 3:20~3:30hrs but way too aggressive for a 4hr finish or more importantly for someone who's trained for a 4hr finish.
I believe a good rule of thumb is that the 2nd half of a marathon should be your 1st half time +10mins. EG for a 4hr finish, 13.1 split @ 1:55 leaving 2:05 for the 2nd half.
Sounds like you went off like a bat out of hell and paid the price. You where doing 13+kph when to do a 4hr marathon you only needed to sustain a 10.5kph pace.