Fueling for marathons - is it REALLY necessary?

I agree that you can teach your body to burn more fats than carbs. But it’s still n=1. For example, I’m 155lbs, I don’t feel the need to take nutrition on a long run. My buddy, 135lbs, does. He even takes 3 gels on a 1:22 HM. He just needs the carbs! Maybe he could train himself differently, like you do by default. But some people are totally carb dependent.

My diet (including the beers, and well, some wine, too) and training is pretty similar to yours. I do almost all my running, including 2.5+ hour runs, fasted. However, I did take in calories in my last marathon. And I actually feel like I maybe needed some more calories in the last 45 minutes or so.

Out of curiosity, how fast are you doing the marathon? I'm around 3 hours. I know plenty slower than me who can take nothing in. I don't know anyone in the mid-2's who does it on no fuel.

I do all my long runs with minimal to no fuel. I used to do the same for race day bc of digestive issues. This go around, I took one gel (Vfuel Peach Cobbler...malto eliminated stomach rot) before start and every 45 min... never felt bonked for the first time in 5 marathons.

I now know that my body needs more fuel. I'm an idiot for waiting so long to realize it.

So go ahead and tell us your PB’s. If you are honest about them it will be clear that you are slow. No elite marathon runner is going to run a marathon without “fuel”.

Time’s please wrote:

So go ahead and tell us your PB’s. If you are honest about them it will be clear that you are slow. No elite marathon runner is going to run a marathon without “fuel”.

2:25:17. So, not “elite”. Hoping to get there though. I am not trying to say that fueling is unnecessary; I am genuinely asking the question as I am looking for ways to improve.

yes agreed with u

ToFuelOrNot wrote:

Time’s please wrote:

So go ahead and tell us your PB’s. If you are honest about them it will be clear that you are slow. No elite marathon runner is going to run a marathon without “fuel”.

2:25:17. So, not “elite”. Hoping to get there though. I am not trying to say that fueling is unnecessary; I am genuinely asking the question as I am looking for ways to improve.

Pro tip: try fueling during your race to improve your time.

ToFuelOrNot wrote:

Time’s please wrote:

So go ahead and tell us your PB’s. If you are honest about them it will be clear that you are slow. No elite marathon runner is going to run a marathon without “fuel”.

2:25:17. So, not “elite”. Hoping to get there though. I am not trying to say that fueling is unnecessary; I am genuinely asking the question as I am looking for ways to improve.

2/10

Obviously you found what works well for you. I would still argue fueling is necessary to reach your limits in a marathon for at least 95% of people. But if you don't want to risk messing with your routine then don't.

some other guy wrote:

Obviously you found what works well for you. I would still argue fueling is necessary to reach your limits in a marathon for at least 95% of people. But if you don't want to risk messing with your routine then don't.

This is definitely my thinking, but my buddy (who, as I said, is more knowledgeable than I am) insists that I could cut a minute or more if I worked to incorporate fueling. I just have a hard time seeing why when I have had success and felt very good at the end of races without it.

Also - I did not start this thread under my registered name or list my PR intentionally for fear of “you obviously already know” type responses. I am not nexessarily confident that I do know. I could be persuaded to try fueling if strong evidence was provided in support of it even if that evidence came from someone “slow”.

Few things:

The research indicates that as long as you properly carboload, you're probably okay not fueling during a marathon.

The fact that you feel good at the end doesn't mean that fuel won't help you. There's anticipatory regulation of speed, where your body will slow you down in order to preserve fuel stores. This can happen surprisingly early in the race, and although it's subconscious, it's influenced by your conscious knowledge of how far you're running. Fascinating stuff.

The ability to burn fat is only slightly trainable. It's very trendy to talk about learning to run on fat, but at high intensity, it really doesn't work. To get the same amount of energy, fat requires more oxygen.

The research on water is also pretty inconclusive. People who start out a race dehydrated do worse, but among those who are properly hydrated to start, there's a correlation between dehydration and speed. Perhaps it's because it's just too hard to rehydrate at such fast speeds, but it still suggests that on balance, dehydration isn't something to worry about in a relatively short race like a marathon.

Anyway, why not experiment. Personally, I've found that some carbs help me finish faster, but I keep to the low end of the recommended range. I also don't drink water in races, period. Guaranteed side stitch for me.

Bekele has the WR for a marathon without fuel in London 2016. Not only did he get little training in after nearly a full year of not been able to run but his fuel was stolen by the doped pacer in that race. I'd like to see anyone else beat him if they had his disadvantages.

In fact it was quite common for elite runners not to fuel at all during marathons until the late 60ies/early 70ies, and they were able to run low 2:10s or even faster. They did not even drink water.

Time’s please wrote:

So go ahead and tell us your PB’s. If you are honest about them it will be clear that you are slow. No elite marathon runner is going to run a marathon without “fuel”.

I'd like to know what fuel Steve Jones used.

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.

You should experiment with gels in your long runs to make sure they don't cause any stomach distress and then try it in a marathon. You spend hundreds of hours training and hundreds of dollars to register for and travel to races. It just seems silly to leave a simple performance boost on the table without even trying it.

2:25 is solid. And since you're almost at an OTQ, I would perhaps experiment with some fueling if I were in your position. But on the other hand, it it might only be worth a minute, is that worth it? I was guessing it could be more. Though it might depend on any fade over a given runner's final miles. Not that carbs would cover all of that. But if someone is bleeding 30 seconds a mile for the final 10k, could proper fueling cover half that? If it could, well, that's why I think I'd experiment a bit if I were you.

I'm sort of similar in that I run all my training in a fasted state. I'll carry a gel during my long run and then never take it because I'm not hungry or feel at a loss of fuel. I take in gels during races because "I'm supposed to" but don't feel any better or worse because of it. In my best marathon I only took 1 and ran in the 2:40s. In my worst marathon I took 3 gels and still "bonked".. I think it had more to do with flying across the country and not getting any sleep.

Thanks for the feedback; this has been helpful. I guess it is true - why not experiment? I have a marathon planned for the end of April and will give Gu or something similar a try on some of my long runs during the cycle. I had never considered that my body may slow down in attempt to mete out my energy stores at the end of the race. During my PR, I did get into the high 5:20s for miles 15-20 and then went back to the low-mid 5:30s for the final 10k. I had previously thought that this was due to the adrenaline I experienced from 15-20 (I was 2 minutes down at halfway and caught the leader at 20.4 miles), but I suppose it could have also been a fueling thing. I had not considered that. As many have said, it's worth a try.