Complete Guide to Running Fuel

When I started training for my first half-marathon, I was so surprised to learn that I would probably need to eat while racing.  My mind went insane.  How in the world do you chew, swallow, and eat food while you’re moving?!  I could barely navigate the sidewalk without tripping over nothing, and it took every ounce of mental fortitude I had to not sit down on the curb during most of my runs.  I couldn’t imagine trying to throw eating on top of all that.  10 years later, and I wouldn’t dream of heading out the door for a long run without multiple running fuel options.

It’s taken a lot of trial and error, patience, and some close calls with GI distress to learn what works well for me. And much like the development of babies in the first year of life, just when I think I have my fueling figured out something changes and I have to recalibrate. Because what works well is so individual, I don’t want to give recommendations on any product over another. I’m happy to share what works for me, with the understanding that my stomach and your stomach may not be on the same page.

long run fueling - running fuel - running gels - what to eat for a long run

But what I can do is share some different options, and encourage YOU to explore and experiment until you find something that works well for you.  I also want to share how these different fueling options can be used most effectively, and who might find them more or less appealing.

Before we get into the different fueling options, it’s important to consider a few guidelines for good fueling strategies.  According to conventional advice, runners are encouraged to eat roughly 150-300 calories per hour of running for any runs that go beyond an hour.  Every runner is different, but if you find yourself feeling low on energy, you’ve waited too long.

So a few pieces of fueling advice:

  1. Use long runs to practice your fueling
  2. Be willing to explore different kinds and types of fuel
  3. Make sure to drink water when eating fuel
  4. Plan to eat before you feel hungry
  5. If you find yourself feeling “out of gas,” this likely means you need fuel more and sooner
  6. Don’t force yourself to run and eat – you can certainly walk a few steps without any significant consequences

And if you need a few idea’s for what to eat BEFORE you head out the door, check out my recommendations on What to Eat Before a Run.

Complete Guide to Running Fuel

Now that we’ve covered the basics of HOW to eat while running, here are some of the options worth giving a shot during your runs.


Gels are probably the most well known fueling option for runners.  And for good reason.  Gel packets are small, convenient, and usually pack a 100+ calorie punch.  They require zero chewing, so if you are someone who wants to save as much energy as possible, these may be a good option for you.  And let me happily tell you, there are about a thousand options with it comes to running gels. 

There are traditional gels from companies like Hammer, ClifShot, and GU that are created in labs to serve the purpose of providing easily digestible carbs in a tasty flavoring. If you don’t mind the texture of gel (it’s exactly what you think of when you hear the world “gel”), you will definitely be able to find a flavor that appeals to you.

long run fueling - running fuel - running gels - what to eat for a long run

In recent years, there have also been more companies focused on providing gels that are created with more natural ingredients.  Products like HoneyStinger, Huma, and Spring Energy are all options I have had good luck with.  HoneyStinger is made primarily with honey (makes sense, right?), where Huma features energy from chia seeds, and Spring Energy is more of a pureed fruit option.

Some people prefer the convenience of traditional gels since they are available at most running stores and even grocery retailers.  Many runners find that some of these fuels are harder to digest.  For runners who have a hard time with traditional fuels, I would recommend giving one of the more natural gels a shot to see if they are easier on your system.


Chews are really an evolved form of gel.  They are great for anyone who has a hard time with the consistentcy of a gel, but still want something that is quick and easy to digest.  If you are someone whose stomach churns at the thought of a gel, chews might be a better option for you.

Similar to gels, there are traditional and more natural varieties. They are often made by the same companies that produce gels. Some things to consider when selecting a chew to try out, besides flavor, are whether they are caffeinated or non-caffeinated, how many chews are considered a serving, and how firm or solid they are.

long run fueling - running fuel - running gels - what to eat for a long run

One interesting option in the space is SportsBeans, which are essentially a cross between jelly beans and chews.  They are pretty tasty in my opinion, and potentially more palatable for some people.  Other chew options to keep an eye out for are ClifBlocks, GU Chews, Skratch chews, HoneyStinger, and Gatorade chews.

The one downside I caution runners to be aware of when it comes to chew-type fuels is that they do take up a bit more space than something like a gel.  Not a big deal if you can get away with carrying one package, but a little more challenging if you find that you need take 3 or 4 with you.


If eating on the run is just not your jam, don’t worry, I’ve still got recommendations for you!  There are tons of great options that require zero chewing.  Just mix up a package with some water, and you’ve transformed your hydration into nutrition.  You magician. 

When I started experiencing weird and new GI issues during my runs, I decided to try shifting my fueling exclusively to liquid calories. It’s not a diet I recommend in everyday life (eating is important, friends), but it can solve some problems for some runners. And by some runners, I mean me. I also love the fact that I can take sips of nutrition more consistently throughout my run. Rather than eating 100 calories at once, I can drink smaller amounts, giving my stomach less to process.

long run fueling - running fuel - running gels - what to eat for a long run

Ultra-runners have long known the benefits of liquid fueling, but drink mixes are becoming more popular in the road racing community lately as well. For ultra-runners, one of the biggest benefits of liquid calories is how easy it can be on the digestive system. Traditional fuels recommend consuming 4-8oz of water with every serving. That’s not what you get in the half a dixie cup that’s handed to you at mile 8.

If you don’t properly hydrate with your fueling, your stomach can have a harder time breaking things down. Which can lead to GI distress. The other great thing about liquid calories is that runners have the option of dilulting or concentrating the mix. If you need more calories, add less water. Easy peasy! Most of these mixes also include elctrolytes, which means that runners can get hydration, electrolytes, and calories all at the same time.

long run fueling - running fuel - running gels - what to eat for a long run

At this point, I have tried out both Nuun Endurance and Tailwind.  I love the flavor of Nuun endurance and have found that it doesn’t leave an after-taste or feeling of grit in my mouth.  However, when it comes to the cost per calorie, it is a slightly more expensive option.  1 scoop = 60 calories, while 1 scoop of Tailwind = 100 calories.

I usually adjust my concentration when I carry Nuun so that I get more calories, but it is pricier than Tailwind.  Which I also love.  Both options have caffeinated and non-caffeinated varieties.  One option that I haven’t tried personally is Skratch Labs, but I’ve heard other runners have had great success with this product as well.

One item to consider with liquid calories is the fact that you do have to carry water with you.  May not be a big deal on a trail run, but can be unwanted additional weight in a road marathon.  If you’re not prepared to carry water during your race, I’d recommend looking for solid calorie options.

Regular Food

Not every runner wants to eat something different than foods they would eat as a regular snack.  For runners who prefer real foods, there are plenty of options.  Most fruits (dried or raw) can work decently well, but watermelon, bananas, and grapes are some of the more popular options.  I’ve found that if you can find a way to keep them cold, frozen grapes are absolutely amazing on a hot run.  If you want something close to a whole food, but with the convenience of single serving packaging, HoneyStinger or Stroop waffles can be a great option.

Related Post: Insane Things Only Runners Understand

long run fueling - running fuel - running gels - what to eat for a long run

While not considered real foods, options like pretzels, oatmeal balls, and the good old fashioned PB&J sandwich can also provide a quick hit of calories. I do recommend some caution with some of the heavier foods, as digestion can be problematic. If you’re planning on running a fast race, these may not be the best options for you.

There’s also the option of the gas station finds.  Foods that you maybe wouldn’t intentionally rely on for fueling, but can be great when you unintentionally drop your chews on the parking lot ground.  Or just walked out the door half-awake.  Things like Starbursts, Gummy Bears, Jelly Beans, Skittles or ClifBars can do the trick, but be careful with how well your stomach can handle foods that haven’t been trialed.


While not technically considered a source of calories or fuel, it is important to remember that runners need to be conscientious of replenishing their electrolytes either after or during a run.  Especially during Summer months, when hot and humid runs mean more sweating.  Not replenishing electrolytes can make it more difficult for your GI system to process your fuel, and can contribute to feeling more depleted.

Related Post: Running in Heat & Humidity

I have had nothing but great experiences with both Nuun and Liquid I.V. as electrolyte supplements. I typically use Nuun on any day that I exercise more than one hour outside, and reach for the Liquid I.V during my weekly long runs. Liquid I.V. has gone a long way to help me reduce muscle cramping and stomach issues during my long runs. And now that my trail runs are exceeding 3 hours, I definitely need all the extra help I can get for surviving.

long run fueling - running fuel - running gels - what to eat for a long run

There’s also the option to take salt tablets before or after a run, as well.  In the past, I’ve used SaltStick, and have had no issues.  I just prefer the sweetness of liquid electrolytes.  I’ve also grabbed single serving Coconut Water to guzzle after my long runs when the weather is particularly humid.

Is this a complete list of every fueling source available to runners in the U.S.? No.  It would take me months to get a full list, and there would probably be new options by the time I finished.  But I hope that having list of options has helped you realize that if a running fuel isn’t working for you, there’s so many others that might be exactly what you need.  You don’t have to run with an upset stomach.  You don’t have to take fuel that tastes disgusting.  Keeping trying other fuels out until you find something that works and is palatable.  Just like running shoes, there’s a million options, and one is bound to work perfectly for you.

And if you have a suggestion on a great, but lesser known, running fuel, I’d love to hear your recommendation in the comments.  I’m always looking to try out new kinds of nutrition!

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