Well done! How much did you knock off your previous PB?
Since I've never raced a marathon before, I was wondering what people did in terms of nutrition?
For a half-marathon race I wouldn't normally require any gels or hydration since it's so short but I will need to for a full.
technically about 6 minutes but I don't race often. last October I was on rack for a sub 1:25 but got a killer side stitch and I was forced to walk for a few minutes before picking back up to a slow jog but never rally got back to speed, came in at 1:28 which was still enough for 4th in AG. Strangely, my time yesterday would have been top 5 overall at my October race despite a much harder course yesterday.
For a full Marathon I start crab loading 2 days before the race. Lots of pasta, rice, fruit potatoes throughout the day, along with plenty of water. Don't get on the scales, you'll be gaining water weight. I try and wake up 3-4 before the race and start again with some basic carbs. bananas, sports drinks, white bread, Nothing with any fiber, minimal fats and proteins. Plenty of water and sports drinks, and just try to be maximally hydrated. this also involves peeing lots. I stop any eating and cut down on drinking with an hour to go, and pretty much just circle the toilet line to make sure bladder is empty. The aim os to be completely hydrated, but bladder empties in a kind of equilibrium, with glycogen stores totally topped off and blood sugar high. 5-10 minutes before the start I down an energy gel, and then I take one every 40-45 minutes. You have to take them well before you think you need them, its too late if you think you are getting tired or low on energy. Ideally you need to practice this on your long runs and find out what gels you can stomach. A lot of people get bad GI issues when running Marathon at race pace. I'm not too and but I certainly feel slightly nauseous and don;t feel like eating a gel buts its needed for a marathon. You are going to burn around 300-3500 calories, your glycogen store is about 2000-2200. You'll burn some fat but not enough to make up the difference, and once your glycogen gets low you are going to enter a world of pain in the last miles.
Hydration is tough. Until now I have always ran marathon with a hydration belt, 2x10z bottles with weak sports drink Gu Roctane. This gives some much flexibility in drinking whenever you want, having your fav sports drink, avoiding busy aid statiosn, or aid station on the wrong side of the road, or when there is someone right in front of you that takes the cup you were aiming for etc. Also, for taking gels its great just to be able to swirl some liquid in your mouth between swallowing mouth-falls (try and slowly take a gel over the course of 5 minutes so you don;t get one blob of sugar sat in your stomach, also helps the miles tick by). Also, as I get faster it gets harder and harder to drink from the paper cups without slowing down. I start choking on the water they hand out, or it goes all over my face and chest.
however, I'm now at a running pace where the hydration belt is a definite disadvantage. The extra weight might cost me 20 seconds in a Marathon, which for most people is nothing But I think I am borderline 2:55 shape. 20 seconds might matter. moreover, at >8min a mile i find the belt super comfortable and I just occasionally tighten it on my long runs. when going at under 7:00 the additional forces means it bounces around more, get loose every 10 minutes or so when the bottles are full. So I am looking for additional options but everything seems to suck. Relying on the aid stations is just so risky, I don;t like it. I don't want to be slowing down just drink - its not even about the time lost but I don't like breaking rhythm. Last November I was going to try without but in the last hour chickened out and put it on for the race and it was fine.
For your first marathon I suggest getting a hydration belt. You are also at a speed where it might be annoying, but it will be one less factor to worry about. In any case, I take my belt with me on every single long run (and in the summer anything over 13 need serious water here). useful to hold gels, phone, keys, credit card, driving license etc. Some logn runs I have popped in to a super market to get a bottle of Gatorade etc. If I end up a long way form home its nci to have a phone with me if I have to stop (exhaustion, twisted ankle, gneeal runenrs pknee pain etc).