Fueling for Distance Running

Typically people will refuel on runs lasting longer than 90-120 minutes. Distance is less important as this is a function of how long it takes to use up your easily accessible on-board carb storage. So running longer typically goes better if you refuel while you’re doing it. You’ll definitely want to do so during a race as that’s absolutely when you want to run best. This is entirely normal and expected.

There are bazillions of calculators to help figure out what you need (for carb intake per hour). I’d suggest starting around 20-30g and see how that works. That’ll probably be a gel packet or about 100 calories of energy chews per hour. How your stomach tolerates things and how you feel with different options is something you want to experiment with during training. Some people do great with gel, some people prefer smaller doses more frequently. Luckily there are loads of options. If your stomach is blessed, you will tolerate what your race provides (typically Gu and Gatorade).

You will feel much better. And it’s 200-300 calories tops for a half. And much better to fuel properly for a good run if you’re training for a race.

I start to lag about 100—110 minutes into a run. Distance varies hugely depending on what I’m doing. If I’m running for a couple of hours, I don’t bother refueling. If I’m running longer than a couple of hours, I refuel.

I don’t tolerate gels well-so I use energy chews (and Tailwind after about mile 16-since that’s when my stomach can’t tolerate anything solid anymore). I typically average about 20g carbs/hour starting in the second hour.

I do prep a bit the day before - not high fat/fiber foods and maybe some extra carbs. I have oatmeal/banana the morning of and I don’t move without coffee.

So as you can see-it’s pretty individual and you’ll just try things out to find out what works. A half is a significant physical effort-it’s not really the time to be scrimping on calories. So give yourself what you need. And that will be highly individual.

Congrats on the progress! It’s so exciting to hit these milestones.

For a half, I eat at mile 9. I do find that hydration helps- Gatorade or nuun.

For full marathons, I bring peanut m&ms. For a half, I do a gu at mile 7 or 8 depending on fatigue and such....that’s because I don’t include the one minute walk break.

I always eat oatmeal with cocoa, peanut butter and honey before a long run. Dinner before is a burger and fries.

After having run a lot of long distance, I can tell you it will be trial and error. Don’t let the “errors” slow you down. Also make sure you are fueling throughout the week. It is so hard to train in a deficit.

Enjoy your first half marathon!

Are you drinking enough water ? If you are somewhere warm and running for a while dehydration can make you feel fatigued. Also what are you eating ? I agree with littlegreen.. that eating beforehand is important because it will fill your glycogen levels up. I personally try and avoid very simple carbs while exercising because of they way they affect my blood sugar. I peak and then crash causing me to bonk just because of what I've eaten. I watched a programme about Wiggins (UK cyclist, tour de France winner) who swears by jam sandwiches :-) They work pretty well :-)

If you're maintaining a significant deficit, that can certainly impact performance as duration/distance increases. Fortunately, a half *shouldnt* require a substantial overhaul to your eating plan.

When my training gets heavy, I'll keep my lower calorie days for during the week when my training is lighter, then eat at or close to maintenance on the weekends when I have my longer workouts. It works for me and my preferences - your mileage may vary, but I do think there is merrit in the approach.

As for when to eat during the run... about 30 minutes before you start to struggle. If you know that's around a certain mile-mark or time, then you should be able to plain it fairly well.

Honestly I’ve come to the conclusion that what matters more is increasing the body’s tolerance of higher mileage (by running more/more miles) rather than fuel. At very high mileage - marathons etc- fueling starts to matter more, but not at shorter distances. I used to be quite concerned about fueling and tried Gus and chews and all that. Now I just run first thing in the morning on an empty stomach, even when I’m feeling hungry, and those often end up being my best runs. I think a lot of it is mental : having a gu at mile six or whatever provided a nice mini goal to look forward to.

However, I had the opposite problem of having a sensitive stomach during runs, so keeping it empty was always the safer option for me. If necessary I prefer to go for a simple Gatorade or similar to get a bit of a kick without the gi stress. You’ll have to see what works for you.

But it might also depend on where in your training you’re at and how long/far you’ve been running in general? If you’ve recently increased your mileage or started a new training plan, sticking to a 500 calorie deficit at the same time still sounds like a lot to me. The general recommendation I’ve seen is to try to lose weight during down time and go up to maintenance while doing hard training. Both keeping a significant calorie deficit and upping your training at once is a pretty big ask from your body. Also, if you’re doing a traditional training plan with a long run, your calorie counts are going to vary a lot from day to day. You might consider eating to a weekly average, if you’re not doing so already.

speyerj wrote: »

Thanks for all the advice. Regarding some of your questions: I started running in November last year, but started training for the half in January. My half (now virtual ) is on July 4th. I'm averaging about 1500 to 1700 calories a day right now and have been losing between 1 to 2 pounds a week, but just recently decreased my deficit to slow the weight of loss to 1 lb/week. My daily calorie totals fluctuate, because my calorie burn fluctuates. I do short, fast runs (30 to 45 minutes) on Mondays and Fridays with strides, tempo or fartlek runs on Wednesdays. I've been building up my mileage slowly on the longer runs on Saturdays. As a beginner and still about 15 pounds overweight, I'm not fast. While I can do a 5k in under 30 minutes, my long slow runs are slow - about an 11 minute pace on a good day, so 9 miles takes me 100 minutes. I started carrying water for any runs over 6 miles, so I am hydrating along the way. I do think ingesting something after an hour of running, before I start to crash, might be good to try on my next big run and see how whether that makes a difference. I'll try that Zip-Fizz suggestion too for afterwards! I'm grateful that this coming weekend I get to dial it back to 5 miles before tackling 10 miles the following week.

From what you've said here I'm going to suggest you try slowing down a bit. I run distances, on trail for preference, and am on 12/13 min miles. Was working towards an Ultra before we got all screwed up.

Anyway, I have been increasing my distances gradually over the winter, and had got up to 18 miles. I have found the most effective strategy is to not worry about the speed while I am trying to increase the distance. As you get more used to the distance, and run more longer runs, your speed tends to pick up anyway.
The more steady approach might also help stave off the crash that your experiencing.

Just a thought, experimentation is always going to be the best way to find what suits you.

speyerj wrote: »

I do short, fast runs (30 to 45 minutes) on Mondays and Fridays with strides, tempo or fartlek runs on Wednesdays. I've been building up my mileage slowly on the longer runs on Saturdays.

I do think ingesting something after an hour of running, before I start to crash, might be good to try on my next big run and see how whether that makes a difference.

So prior to the long Sat, you are doing a short fast high glucose-using run on Fri?
Recovery, either for the muscles in general, but also for glucose restore - could easily be an issue.
Perhaps for the Fri run, figure 80% carb was source for the calories burned.
Are you eating that many carbs after the run prior to Sat?

Also, digestion slows when doing aerobic endurance as blood is not normally sent to stomach for digestion - you'll need to test, but I find on long bike rides if I know I'm going longer than 120 min and will need the fuel, I better start the refueling at about 90 min. There is a lag time even for simple sugars - just have to see what yours is.

But I'll bet you'll find it's other issues that are the cause.

I always used zip-fizz as assist during the workout. Along with other things. Afterwards is much easier.
For sodium/potassium afterwards - a small can of V-8 is great if you can handle the taste.

In both of your meal examples you're getting 120ish and 200ish calories from carbs (1 g carbs = 4 cal) the protein shake with the frozen fruit probably contained more simple carbs that are available fairly quickly. Most endurance athletes that I know tend to eat 50 to 60% of their calories from carbs, you may find that adjusting your macros helps.

Also, if you drink too much water (i.e. your pee is clear) you may be diluting the electrolytes in your blood. Look up hyponatremia.