As both a runner and a running coach, I know how important it is to have a solid fueling plan—especially for long-distance races like the half marathon and marathon. One of the most effective tools for staying energized and avoiding the dreaded wall is using energy gels.
These small but powerful packets provide a quick source of carbohydrates to help preserve your glycogen stores and keep your muscles firing through every mile.
In this guide, I’ll walk you through everything you need to know about running with gels—including what they are, how they work, when to take them, and how to decide if they’re the right choice for your fueling strategy.
What Are Energy Gels?
Energy gels are one of the most widely used fueling tools for endurance athletes. They provide a quick source of carbohydrates—usually around 100 calories or 20–25 grams per gel—to help maintain energy levels, preserve glycogen stores, and delay fatigue during long efforts.
Most gels contain a blend of simple sugars like glucose and fructose, though some use maltodextrin, a less sweet, easily digestible carbohydrate that can be easier on the stomach for some runners.
Formulations vary by brand, and ingredients like electrolytes (sodium, potassium, magnesium) and caffeine are often included to support hydration and focus.
Runners who are sensitive to fructose should look for gels made primarily with glucose or maltodextrin to reduce the risk of GI issues. Likewise, if you find gels overly sweet or thick, options with a higher ratio of maltodextrin tend to have a more neutral taste and smoother texture.
Caffeine can enhance endurance and alertness, but it may also cause digestive distress or an increased heart rate in some individuals, so it’s important to test caffeinated gels in training first.
Ultimately, the best energy gel for you will depend on your personal taste preferences, digestive tolerance, and fueling needs. Always try different brands, flavors, and timing strategies during long runs to find what works best—never experiment for the first time on race day.
Why Running With Gels Works
Because the carbs in energy gels are simple sugars, very little digestion is required before the sugars can enter your bloodstream as usable glucose.
This means that you get usable energy quickly, and the digestive system does not need to work hard to break down complex carbohydrates, proteins, fat, or fiber, which take quite a bit of time and are relatively incompatible with high-intensity exercise.
This is because when you are running or performing the high-intensity exercise, blood flow increases to the heart and muscles, and to compensate for the higher oxygen and nutrient needs of these tissues; blood flow decreases to the digestive tract.
This is why it is difficult to digest food while running, and consuming too many carbohydrates, a heavy meal, fatty foods, or excessive fiber or amino acids before or during exercise can cause cramping, bloating, diarrhea, gas, nausea, and vomiting.
Energy gels, energy chews, sports jelly beans, Gu chomps, and sports drinks are running nutrition products specifically formulated with only simple sugars so that the digestion is minimal and the fueling provides a quick energy source to keep your energy levels stable during longer runs or races.
Note that energy gels aren’t necessarily “healthy” for your everyday running nutrition plan. They are highly processed, but this type of running fuel has its place in your training and racing.
There are also more natural energy gels like Huma Chia Energy Gels. Studies have demonstrated1Lestari, Y. N., Farida, E., Amin, N., Afridah, W., Fitriyah, F. K., & Sunanto, S. (2021). Chia Seeds (Salvia hispanica L.): Can They Be Used as Ingredients in Making Sports Energy Gel? Gels, 7(4), 267. https://doi.org/10.3390/gels7040267 that chia seed gels can provide equally effective performance benefits to standard processed energy gels.
When Do You Need to Use Gels?
Using energy gels is usually unnecessary if you are running under 60 minutes.
When runs and races approach the one and a half hour mark, fueling becomes necessary to perform at your best.
This is because you will need to preserve your glycogen stores, manage your energy levels, and prevent the dreaded feeling of bonking when your muscles run out of carbohydrates as a fuel source.
According to the American College of Sports Medicine (ACSM),2American College of Sports Medicine. (2009). Nutrition and Athletic Performance. Medicine & Science in Sports & Exercise, 41(3), 709–731. https://doi.org/10.1249/mss.0b013e31890eb86 endurance athletes in general should ingest 30–60 grams of carbohydrates per hour during workouts lasting 1-3 hours or more.
Because each energy gel has about 25 grams of carbohydrates, you should have one gel every 30-40 minutes.
If you want an even more specific calculation for you individually, you can use a simple formula to estimate your carbohydrate needs for optimal performance.
Keep in mind that this is a general guideline based on body weight, and individual needs can vary depending on factors like intensity, weather conditions, and how well your body tolerates fuel while running.
To estimate: Your weight in kilograms = grams of carbohydrates per hour you should consume.
So, if you weigh 70 kilos, aim to consume around 70 grams of carbohydrates each hour during the race–about 2-3 gels depending on the nutritional content.
How Do You Carry Energy Gels While Running?
There are different ways to carry energy gels during a marathon or long run, such as:
- Tucked in the pocket of your running shorts
- Pinned to your shorts or race bib
- In your hydration pack
- Pinned to the inside edge of your hat
- Holding gels in your hand
- Wearing a waist pack or hydration belt
- Putting them in the pocket of a handheld water bottle
Are There Any Alternatives For Fueling?
Other sports nutrition or running nutrition products can be used instead of energy gels.
Remember that some of the alternatives will not provide the exact same number of grams of carbohydrates, calories, electrolytes, or overall nutrition, so you will need to look at the nutrition facts when designing your fueling strategy.
Here are some sports nutrition energy gel alternatives, many of which you can get on Amazon or your local running store:
- Honey Stinger Waffles
- Stroop Waffles
- Gu Energy Chomps
- Sports Beans (some are caffeinated)
- Energy bars
- Energy chews
- UnTapped Maple Syrup packets or similar
- Jelly Babies in the UK
- Sports drinks
There are also alternatives for those who do not like the taste or consistency of gels.
I often recommend trying whole foods alternatives, particularly if you don’t have a sensitive stomach or haven’t had much luck with various sports nutrition-fueling products.
Some of the best alternatives to energy gels for running nutrition include the following:
- Raisins
- Other dried fruits such as dried pineapple chunks, dates, figs, dried cranberries, and dried apple rings
- Banana chips
- Fresh bananas if you carry a hydration pack or a running vest and have space for larger running fueling options
- Applesauce packets
- Baby food packets high in carbohydrates, such as mashed banana, sweet potato, pears, apples, oatmeal, etc.
- Maple syrup packets
- Honey packets
- Yogurt covered raisins
- Jelly beans
How Do You Use Energy Gels?
#1: Practice Your Marathon Fueling Strategy
Do not wait until race day to try to use energy gels.
Use your long training runs to practice your exact fueling strategy, including the timing and type of fuel source you will use on race day.
Many runners experience GI upset with excessive intake of simple sugars, but with practice, you can actually train your gut to handle digesting these products while running more easily.
#2: Experiment With Different Types Of Energy Gels or Alternatives
There isn’t a “best energy gels for runners.”
As a marathon runner myself, I have a super sensitive stomach, and I am well aware that certain energy gels work well for me, and some energy gels and sports nutrition products just don’t.
Every runner will have their own preference in terms of palatability, taste, and digestibility for gels, chews, sports beans, sports drinks, or any other type of running nutrition.
Maurtens 100 Hydrogel has no flavor or colors, so it can be a good option for those who just can’t get them down.
Gels come in different thicknesses, from very thick like a paste, to quite liquidy, like a sports drink. Try these different types in your long run to see which ones work best for you.
#3: Drink Water With Energy Gels
Make sure to drink at least 4 to 6 ounces of water with every energy gel to help wash down the consistency and facilitate digestion of the glucose into your bloodstream.
This will also help manage your hydration in tandem with your fueling, so you don’t have to think about drinking sports drinks or water separately from fueling.
If you take energy gels with a sports drink, it may be too much sugar to ingest all at once and can upset your stomach.
#4: Use Your Teeth
It is sometimes difficult to open energy gel packets while running, so if you can’t rip it with your fingers, I sometimes rip it open with my teeth (this is not dentist-approved advice!).
#5: Use Caffeinated Energy Gels Sparingly
If you like caffeine for running to enhance endurance3Guest, N. S., VanDusseldorp, T. A., Nelson, M. T., Grgic, J., Schoenfeld, B. J., Jenkins, N. D. M., Arent, S. M., Antonio, J., Stout, J. R., Trexler, E. T., Smith-Ryan, A. E., Goldstein, E. R., Kalman, D. S., & Campbell, B. I. (2021). International society of sports nutrition position stand: caffeine and exercise performance. Journal of the International Society of Sports Nutrition, 18(1). https://doi.org/10.1186/s12970-020-00383-4 and increase energy levels, consider caffeinated gels.
However, unless you are only having one or two gels on your training runs or during your race, you won’t be able to have caffeinated gels for every gel as this would be too much caffeine.4Mayo Clinic. (2020, March 6). Caffeine: How much is too much? Mayo Clinic; Mayo Foundation for Medical Education and Research. https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/caffeine/art-20045678 Instead, alternate.
Consider working with a sports nutritionist to help you work on a marathon fueling strategy and overall running nutrition plan.
To accompany your race fueling, check out our hydration guide for runners:
