Fueling for marathons - is it REALLY necessary?

fisky wrote:

When GU use first became widespread back in the 1990s, runners would talk about their pre-GU times because the benefit of gels was so great, it almost needed an asterisk after the new performance.

.

Couldn't have been American runners.

I would highly recommend fueling. It’s not going to hurt you if you do it right and there’s a very, very high chance it will help you.

I used to not be able to fuel at all. I did all my runs in the morning without eating and could fast for 48 hours while running 10+ miles a day.. so was fairly kept adapted too. I did a couple 30+ mile training runs at 6:05 avg. pace with no calories and a just few sips of waters.. so you can run far and somewhat fast with zero fueling. BUT, from the evidence, I was convinced I needed to fuel if I actually wanted to race a marathon.

When I started, my gut couldn’t handle sugar water. But over time, you adapt. Get some maltodextrin (super cheap) and mix it with equal parts table sugar. This way you have a 2:1 ratio of glucose:fructose (for maximum digestion rate). (I throw in a Nuun electrolyte tablet too) Dissolve it in about an 8% mixture. So about 38 grams of total sugar in 500mL (a normal water bottle). Then just practice drinking this mixture while running. The goal should be to intake about 120 grams in the marathon race (and corresponding 54 oz of water). I practice drinking little sips about once every 2-3 miles so I end up having around 11, 5oz bottles.. you just sip on the 5 oz over a 1/4 mile or so taking 3-4, 1-1.5 oz sips at a time. Trust me, once you do this in training, it’s not that hard and definitely helps! (You just may have to endure some cramps on some runs early on in training.)

With fueling I ran 32 miles at 5:45 avg. pace and it was WAY more comfortable than the other 30 mile runs. (And I didn’t feel like I was going to die). Then I debuted in the marathon and ran 2:17:45 in a race I ran completely solo (I won by 25 mins). If you want to run as fast as possible (not just fast) you need to fuel. That’s just how it is.

since you run out of fuel at 2 hours physiologically you basically have 3 options

find something that won't spike your blood sugar and take that during the race ( UCAN perhaps)

take gu/gel every 25-30 min and keep topping off(risky)

take nothing in training, extend your ability to burn fuel passed two hours and train your race duration(for me 220 no fuel) and do it during racing. This is the canova approach in training and why most good elite marathoners(not us) will do 40k in the race time or 26.2 slightly slower than MP. It is challenging enough to tap the system without going all out.

the third is the best approach but the most challenging

good luck!

Zersenay Tadese ran marathons without fuel until he did the Breaking2 attempt.

noooooo fuel wrote:

since you run out of fuel at 2 hours physiologically you basically have 3 options

find something that won't spike your blood sugar and take that during the race ( UCAN perhaps)

take gu/gel every 25-30 min and keep topping off(risky)

take nothing in training, extend your ability to burn fuel passed two hours and train your race duration(for me 220 no fuel) and do it during racing. This is the canova approach in training and why most good elite marathoners(not us) will do 40k in the race time or 26.2 slightly slower than MP. It is challenging enough to tap the system without going all out.

the third is the best approach but the most challenging

good luck!

This sounds good, but it just isn’t true. The “2 hour thing” isn’t a very rough estimate... not a magic number. You run out of glycogen when you run out of glycogen... (although you never completely hit zero). This is variable by a number of factors:

1: how much glycogen you start out with. Not all humans have the same amount of glycogen stores in muscles. Training and diet affects this.

2: The rate at which you burn glycogen... mainly determined by intensity. The harder the intensity, the higher percentage of carbs you burn... so when I run for 3 hours at easy training pace (like 6:30 pace for a 2:17 guy) I burn a lower percentage of carbs and don’t come that close to running out of fuel... you can train to burn fat more efficiently so you spare carbs.. but only to a point and certain speed. Basically your body learns to run at a pace where it can burn enough fat to get you through the race without fuel.. you may run somewhat fast.. but you’d run faster if you trained yourself to burn carbs and intake carbs during the race.

3: Depends on how many carbs you take in. Most people can digest about 60-90 grams of carbs per hour.

For marathons, you need to master the art of fueling in order to run your *absolute fastest* This just isn’t debatable for the vast majority (there’s always outliers). Ultras are totally different.

some other guy wrote:

Obviously you found what works well for you...But if you don't want to risk messing with your routine then don't.

This is the dumbest response in this thread.

You've found something that works for you. But it is likely not optimal. You'll never know unless you try different things. You can assume and pretend you know better for as long as you want.

You'll get stuck on one plateau, and might find that adding fuel mid-race will lead to a higher plateau. But remember that training your body to process calories while running will take time, so again, don't knock it before you really put in some good training doing it.

Good luck.

At least one study has shown it could dramatically increase your performance.

https://well.blogs.nytimes.com/2014/10/29/sports-gels-can-improve-marathon-times-but-pace-them-right/

OldAndInTheWay wrote:

At least one study has shown it could dramatically increase your performance.

https://well.blogs.nytimes.com/2014/10/29/sports-gels-can-improve-marathon-times-but-pace-them-right/

Holy crap 2 gels at the start line and then 12 on course?! And 2 cups of water before the start and then 20 cups on course?!! That seems a little excessive.

Sure you're going to be develop to burn fat more efficiently, but don't act like you're anything but human or are somehow better than professional/elite runners who eat breakfast before races and GU during. You hit the wall late in the marathon and it's because of glucose depletion. Don't be arrogant and think you are better than that.

GaryOak wrote:

Zersenay Tadese ran marathons without fuel until he did the Breaking2 attempt.

Is this a joke? He also didn't break 2:10 until this year despite being a low 58 min half marathon guy.

28 eight people, that’s a very small study. Probably sponsored by Gatorade..

I think this is the ideal scenario.

First learning your body to burn fat very well and then use sugar in a few preparatory long runs and in your race.

Train without fuels (incl. 26.2mi LRs) and run the marathon with gels on miles 7-8, 16, (on course fuel@18 if desired), and at mile 22. Try it; it feels amazing. I think training without gels and then using them on race day is the way to go.. Your body isn't used to getting fuel, and at my first gel mid-race, it feels like I'm totally resetting my run. You do, in some sense, with an accumulated downhill in energy due to fatigue, but the carbs/fats really replenish a ton of energy. I don't really get how "the wall" still exists with gels, other than it being a psychological thing.

having run 35 marathons (best 2:32:12), i believe eating a lot of carbs (for example, just take pasta, cook it, and eat it with no sauce) . it is a good even on race morning. Use gu during the run , it helps. the gu will not give you some great boost, but i will slow down the coming fatigue. train with some gu on long runs . it can get stuck in your throat and if you are at 22 miles in a marathon it can cause a problems if it gets stuck in your throat . there is way too much effort put in even for us amateurs during training to experiment. don't do a oneoff. list to the bulk of experience over the past 40-50 years and focus on the other aspects of your training like running, injury prevention, recovery, ...

good luck

Steve Jones ran 2:07 on Diet Coke and Mars bars. What you eat and drink does not matter in marathons.

This is one of the best humblebrag threads I've ever seen.

Time’s please wrote:

No elite marathon runner is going to run a marathon without “fuel”.

You sure about that?

Geb ran his debut London marathon sans carbs (i.e., only water). 2:06:35. (BB said Bekele ran a London without carbs due to a pacer taking his bottles? Is that true? If so, another 2:06 without carbs. But Geb's was faster!)

Now he did have a rough last few miles (and the above article attributes ALL of that to his lack of fueling), *however*, this can't, with any certainty, be attributed to no race fueling.

A) he claimed he stepped on a cobblestone and his calf or hammy (forget) tightened up, forcing him to slow that last few miles

B) It was his first marathon ever. Even greats like Geb don't run usually run their best in their first try.

Now subsequently, Geb did start taking carbs during his marathons. He got faster. But again, one can not attribute his improvement to this alone (if at all). He ALSO ran some marathons about the same time as his London debut, and some significantly slower than his London debut, when fueling.

Long story short: fueling is NOT necessary to run a super elite marathon time. However, it could give you a very small improvement, which every runner seeks.

I used to run marathons on nothing. I always bonked and never understood why. This was in the 80's. I finally realized that I should eat before. So, I got up one race day,, about 4 AM, ate a bagel with peanut butter , the race was at 8 AM, and saw results in the race.

Discussing the need to fuel without discussing what you're fueling is like discussing the need for income without discussing lifestyle. Fueling needs differ with body types. OP, you must be very thin, even by runner standards, and you're probably off the charts thin by society's standards in general. That's great, but it probably means you shouldn't be taking fueling advice from less capable runners.

Fueling doesn't necessarily help everyone and of course doesn't help with every distance.

Think about the 5k, see what your pace is, then move up toward the marathon, reducing pace slightly with each increase. Where do you end up? Based on 5k, 10k, and 1/2 times, you should be able to determine your best marathon pace as a matter of regression. If you can't maintain that pace for all 26, you need to fuel. If you can, you don't. Some don't.