VLM 2016 - need to take own fuel? (lets get scientific)

Hi all - first post here.  I'm running the London Marathon for the first time this spring, going for sub 3:30, fingers crossed image  

I was planning on taking my own gels in order to keep my body properly fuelled throughout the marathon to avoid hitting the wall, however after finding out about the multiple energy drink and gel stations along the way, I'm wondering if there's any need? Heres my reasoning:

There'll be Lucozade Sport stations on miles 5, 10, 15, 19 and 23, as well as two energy gel stations at miles 14 and 21.5. 

From the research I've done, the body can't absorb more than around 1g of carb per minute; if you consume carbs drastically over that amount then you could experience stomach cramps etc.

Given that the 380ml bottles they'll be handing out contain 24g of carbs, and the gels contain 30g, from my calculations if you're running at anywhere under 8 minute miles then the provided fuel at each station should be sufficient, and your body will just be about finished absorbing the previous load of carbs at the point at which you hit the next fuel station. 

Because of this, my current thinking is just to take a couple of gels (one for pre-race, one for back-up), and ensure that I take in all the fuel at each energy station. 

Is this sensible or foolish?  I'd appreciate any input here especially from experienced racers who may be able to call BS on my assumptions!

(on a side note, obviously I'm posing this question with the assumption that one is happy consuming solely Lucozade Sport and Sport Elite gels)

Thanks!

Comments

  • MillsyMillsy ✭✭✭
    I don't think my stomach could handle all of the liquid in the Lucozade sport. I prefer to take my own gels (4) and use the on course ones as a back up.
  • That's a lot of liquid to take on. I've done it in the past but I prefer to use my own gels and grab water. That way there's no problems if I forget to collect a gel.
  • Go CazGo Caz ✭✭✭

    I couldn't stomach all that sports drink either. I carry my own gels, as I don't like the Lucozade ones and also wouldn't want to rely on finding them at an energy station (what if you miss it?) As for hydration, I grab water.

  • ClagClag ✭✭✭

    Having struggled with gels previously, my last marathon effort involved liquid as the primary energy source. I had bottles at each water station and managed about halfway before getting to saturation point. I switched to gels then & wasn't drinking full bottles to that point. 

    Go with what works for you, remembering of course that when you go faster it can change digestion etc.

  • senidMsenidM ✭✭✭
    So, if you don't take gels, drink energy isotonic drinks you'll hit the wall? Ah, the power of advertising and peer pressure.



    For those of us old enough to have run London in the last century, gels didn't really exist and Gatorade/Lucozade where a novelty. My pb, in '98 was a 3:03, run on water after a good breakfast of muesli and a bit of fruitcake at 8am. No wall hit at any point.



    You hit the wall from being under-trained for the speed you're running, all the gels in the world won't prevent that.
  • You definitely need to get the training right but I do think the wall is a fuelling thing. My legs have fallen off a couple of times in marathons but I've never hit the wall.



    I've hit the wall when out cycling many times - and that wasn't due to speed but simply running out of energy.



    I bet you'd done plenty of long runs for your PB?
  • MillsyMillsy ✭✭✭
    LockersJ,have you totalled up the amounts of calories and liquid you will be taking on board during the marathon if you use that plan. Seems a huge amount.

    Don't forget that if you go into the race well fueled you should already have approx 2000 calories in glycogen in the tank at the starting line.
  • Thanks for all the replies, much appreciated.

    @cougie / @go caz that's an obvious point I haven't thought about RE amount of liquid to take in.  I generally haven't been taking liquid on during my long runs (as we're still in winter) but am anticipating it'll be quite different in April.  Looks like i'm being too ambitious with liquid intake.

    @senidM perhaps it is marketing material which has gotten me worried!  I'm comfortably doing 18 milers mostly off-road at 8:10/mile with two SIS gels without feeling tired at the end; but as this will be my first marathon, and never having hit the wall before, i'm hoping to overcompensate (but not too much).

    @cougie RE pace - this is my first marathon, so will be a PB image  3:30 is more of a finger-in-the-air time, but believe it's attainable given my pace on my long runs when not pushing too hard (around the 8 min mark).  Previously was a 10k runner (around 40min 10k nowadays), still finding my feet with the long distance stuff.

    @Millsy it is a huge amount you're right - certainly more than i'll be able to burn off.

    From the collective feedback it seems more sensible to take a belt and 4-6 of my own gels which i train with, and use the energy drinks only if i require them.

  • RicFRicF ✭✭✭

    I do wonder how many runners have hit the wall properly, as against just becoming progressively worn out.

    Only happened to me once in a marathon when at 20 miles I assumed everyone around me had suddenly speeded up. I'd been fine to that point. Less than 100m later I just stopped.

    Hitting the wall on a bike is worse. You can't apply enough pressure to push the pedals around in any gear. The bike becomes something you haven't the strength to throw away as useless.

  • LockerJ - I think you're doing it wrong.



    If you're running 8 min miles for your long runs - that is your race pace for 3.30 ?



    There's 2 ways this usually works out :



    1. You run all of your long runs at race pace and inexplicably on race day- you can't run at your 'race pace' as you're knackered.



    2. Your race pace of 8 min miles is waay too easy and you blitz the marathon in sub 3.



    Do you have a half time to estimate your Marathon time ?
  • @cougie I'm expecting roughly a 7:50 race pace.  My weekly long runs are usually 40 - 60 secs off that but, but recently I've ran a few long runs at near race pace (minus warm-up / cool-down) to ensure it's a sensible target.  

    Don't have any HM race times unfortunately... I've got Silverstone Half this weekend as part of my training - but I won't be going flat-out, but expecting around 1:35.  There's no chance i'm going to pull a sub 3 hour!  

    Are you suggesting I do my long runs even slower?  I'm typically running four times a week - 1 long 'slow' run (max HR zone 3 as a strict rule), 1-2 recovery runs, 1 interval run to raise AT, and 0-1 tempo depending on my mileage.

  • I'd rather race the half in order to estimate your race time. There's enough time to recover. Double the half and add 20 and that's your best guide for goal time. There's enough time to recover from that.



    You're running out of time to recover from 20 miles at race pace though.



    You have to trust the training. Otherwise the only way to prove the theories is by doing what you're doing and running long at pace which will destroy your hopes of a decent time on the day.
  • MalcsMalcs ✭✭✭

    LockersJ - sorry, bit late with a response here. Just wanted to throw my two penneth in if it's any use to you.

    It took me many attempts to get fuelling right. I did it the hard way and made some horrible errors along the way

    I have experienced the wall. It happened in my first marathon and I wouldn't wish it on anyone. As RicF says, Lots of people say they've hit the wall and struggled through it. That's the same as saying you have flu when you really have a bad cold. If you hit the wall then it's game over. You'll be walking or crawling home and every step will be a struggle. The world around you goes into fast forward as yours goes into slow motion. 

    Like you I was also aiming for 3:30 and had done much of my training around marathon pace. I tried to rely on just Lucozade in that race and it failed miserably. I agree with what has been said already - it's way too much fluid to have to get through. 

    I won't go into all the other things I've done wrong (including training too much or too little, using salt tabs, drinking way too much water) but suffice to say, I wish I hadn't had to learn by screwing up.

    Now I have the fuelling side sorted. I do a two day carbo load (8-10g per Kg bodyweight carbs each day - this makes a huge difference). I have a decent race breakfast. Then I use 4-5 SiS Isotonic gels in race. These are great because they are in liquid form and are far easier to take than the gloopy ones.

    I've not had a problem with energy since using this strategy. The last few miles are always painful but that's completely different from hitting the wall and not having the energy to put one foot in front of the other.

    Of course, the key thing is finding what works for you and trying it out in training. If you come up with a plan and wait until race day to try it out then you could be in for a shock. Don't leave anything to chance - try it first on a long training run!

    How did Silverstone go? Did you race it? I completely agree with cougie that this is your best indicator of what you could accomplish on marathon day.

    Best of luck!

  • I completed London 7 times in 8 years and never hit the wall. I just ran on Lucozade Sport, but carried my own bottle to avoid the scrums at the drink stations and to make sure that I took it according to my training regime. 

    Everybody is different, the key as Malcs says is to practise it in your long runs and stick to that on race day. For example, in my 26.2 mile training runs I would take one bottle of Lucozade Sport and take 3 or so sips every 40 mins and that one bottle would last the full distance. In the race, I start off like that and then fill in with some sips of water at twenty minute intervals for the last third of the race -depending on conditions

  • Would just like to send my thanks for the many replies on this thread.



    Yesterday I completed my first VLM in 3:34 - pretty happy with that considering a suspect knee injury. I took five gels and they worked a treat (with a few sips of lucozade at each station they had). Had to dig in post 18 miles but I suspect that's par for the course!



    Such an amazing, fun and rewarding day. Can't wait to do my next one. I'm a broken man today and am avoiding staircases at all costs!
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