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Carbs during a marathon (Read 109 times)

lagwagon


    I tend to eat and drink very little when running; not at all in workouts, and a gel or two in marathons.

     

    I'm tweaking a bit for my upcoming race and came across this, which showed that prescribed fueling with carbs/caffeine had a substantial impact on results in paired comparison with self directed fueling:

     

    Improved marathon performance by in-race nutritional strategy intervention (Hansen et al 2014)

     

    Without a full read it looks like a decent study as far as "sports science" goes.  Also found a sensible analysis here.  It might influence my habits.

     

    Anyone have thoughts on it?

    bhearn


      Wow. That is a really crappy abstract. Also, a very small study.

       

      In general carbs are beneficial in a marathon. How much is pretty individual; there's no shortcut to experimentation.

       

      Three gels per hour is a lot to try to absorb if you have not practiced that. That used to be my consumption rate for ultras (now it is much lower), so I was used to it. But when I tried that for marathons, I always fell short of that rate. I'd carry gels in a flask, six gels' worth, and ideally take half a gel every 10 minutes. Should last two hours. But always easily lasted three.

       

      Certainly it's not something you should try for Boston if you haven't trained to. The great thing about Boston is there's Gatorade available every mile. That, plus maybe a gel or two, is really plenty for most.

        Lagz, I cannot imagine you being able to choke down 3 gels per hour at the paces you'll be running. I agree with Bob, there are significant individual differences in how much carbohydrate you can take in during a marathon and its really something you can only learn through trial and error. But 3 per hour? Man.

         

        Keep in mind the people in the (small) study were running a lot slower than you will be. Intensity matters. At 8 minute mile pace I could eat a cheeseburger. At 6:28 pace I can barely hold down a gu.

         

        The formula that works for me is 4 Gu Roctane for the whole race, including the one that I take 15 minutes before the gun, so really only 3 while running. That is the maximum I can can consume while running at marathon pace and there have been a few races where getting that last one down was kind of adventure and/or I just couldn't do it.

         

        So my schedule, when a race is going well, is roughly:

        1 Gu Roctane in the corral 15 minutes before the gun

        1 at 6-7 miles

        1 at 13-14 miles

        1 at about 20-21 miles.

         

        ymmv and all that.

        Runners run


        No Talent Drips

          Wow. That is a really crappy abstract. 

           

          as a lay person, I give that a +1.

           

          FWIW, I try and keep hydration and nutrition separate during the marathon. Usually take a gel 10 min before, and 1 every 5 or so miles thereafter. Gels WITH caffeine. Water only at the stops; this has the side benefit of no gatorade stickiness if/when you slop it all over yourself.Typically, by mile 20 I've had all I can take of the gel, so I let it ride from there...maybe taking a gatorade in lieu of a water in that last stretch.

           Dei Gratia

           


          #artbydmcbride

            I'm slow so take that into consideration, but I don't need any fuel for the first half of a marathon, so I take a gu at 14 miles, then at 17, 20, 23.

            I find the brand matters too.  I take Accel gel which has protein and carbohydrate.

             

            Runners run

            runmichigan


              Two comments from my experience (a personal experiment of one):

               

              (1) Most races seem to have Gatorade, but I find there are much better products available (though more expensive) that have better science behind them.  So I generally take water from the aid stations and carry my preferred nutrition.

               

              (2) We have developed an over reliance on gels.  A properly fueled runner should be able to run for 90 minutes to 2 hours without needing any gels.  I do not take gels in a half marathon and will usually not take them before 16 miles in a marathon.


              jfa

                I tend to eat and drink very little when running; not at all in workouts, and a gel or two in marathons.

                 

                 

                This has been me as well, and I know I have been drained at the end of my marathons because I don't take in enough.

                I have been tweaking on this as I have a goal marathon next Sunday. My problem is that Gatorade and gel's really mess up my stomach. I have been taking my own water bottle on long training runs filled with water and Nuun tabs. They seem to agree with me much better than Gatorade does.

                Other than that, I find the Power Gels more palatable than Gu brand. I am going to try and follow Mikey's schedule , and hope I can stomach the last 2.

                 

                MTA- reflecting on 14 marathons run, I have never once stopped to pee. Is that really unusual? Sign of depletion?

                 

                 

                 

                 

                 

                 

                LedLincoln


                not bad for mile 25

                  I've been training with fig newtons, 'cause I like them.  The 6 - 12 - 18 - ? plan seems better to me, because your body needs some time to digest and make the energy available.

                  LedLincoln


                  not bad for mile 25

                    MTA- reflecting on 14 marathons run, I have never once stopped to pee. Is that really unusual? Sign of depletion?

                     

                    I can pee five times during a long training run, but not once during a race. I just turn my kidneys off when racing.