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“If you give a man a fish, you feed him for a day. But if you give him a fishing rod, you feed him for a lifetime.”

We lead different lives, are born with diverse athletic genes, and love a variety of endurance activities. Let’s be frank. The energy gels that we’ve reviewed and worked for us may not work for you. So instead of “forcing” our opinions onto you, Runivore has always aimed to provide you with the knowledge to design nutrition and fueling strategies that suit you.

When choosing your energy gels, we recommend that you take these four criteria into consideration:

  1. Activity type
  2. Ingredient
  3. Flavor
  4. Packaging


Activity – Marathon? Ultra? Cycling? FKT?

First and foremost, what are you fueling for? Which endurance sport discipline? What is the distance? How hard do you plan to go? What’s your goal time?

In addition, if it’s an off-road event at more remote locations, you might be on your own for hours in the wild with few aid stations. Will you be racing light with only your shorts and bike jersey pockets for carrying energy gels? Or is your event a mountain 100-miler where you will have a 10+ liter race vest, a crew, and a pacer?

Click on these links for calorie and carbohydrate calculators to get started. Here are also three rules of thumb:

  1. A relatively fit runner can store between 90-120 minutes worth of glycogen going at a marathon to near lactic threshold pace. If your race is under 90 minutes, you may not need to refuel mid-race. When moving below marathon to near lactic threshold efforts, you may not deplete glycogen stores as rapidly.
  2. Consume 1g of carbohydrate per kg of body weight per hour. This means a 60kg athlete should take in 60g of carbohydrates each hour, about 2-3 energy gels.
  3. Every 20-25g of carbohydrates (about the amount provided in one pack of energy gel) require 250 ml of water to process.

Train your stomach to better understand what your body needs.


Ingredient – What are energy gels made of?

This is especially important for athletes with sensitive stomachs and food allergies.


Carbohydrates are the primary fuel for endurance challenges. They come in complex (natural foods such as whole grains, vegetables, and some fruits) and simple (glucose, fructose, maltodextrin, honey, maple syrup) forms. Simple carbohydrates are easier to process for mid-race fueling and provide a faster mouth-to-muscle reaction. However, I’d suggest using healthier complex carbohydrates for daily nutrition and training.


There are six main electrolytes: potassium, sodium, chloride, calcium, phosphate, and magnesium. Electrolytes are substances that produce an electrical charge and become ions when dissolved in our blood. They then become enablers of critical functions within our body, such as electrical signaling, muscle contraction, sending nerve impulses, balancing fluids in the body via osmosis, and maintaining the blood’s acid-base balance.

Here are two articles on the two electrolytes the human body loses the most during exercise – sodium and potassium.

Natural vs. artificial

There are two schools of thought.

Sugar is sugar. The source of the sugar doesn’t matter because the human body will metabolize it into glycogen regardless.


Natural over synthetic. The production process of artificial carbohydrates is different from how nature does it. Despite the similarities in chemical structures, your body may react less favorably to artificial ingredients. Therefore, natural nutrients are more bioavailable and less harmful.

As with most sports nutrition topics, expert opinions vary, and credible scientific research supports both sides. However, just like training, fueling is more art than science. A person’s body, lifestyle, daily responsibilities, and training goals often determine the most practical solution. Determine what works for you.

If you are interested in more natural options, here are five all-natural energy gels we’ve tried and liked.

Branded-chain amino acids 

For events that go far and long (ultramarathons, ironman triathlon, or peak bagging), you might need more than just sugar and salt. After all, We deplete more than just carbohydrates and electrolytes during exercise.

L-Leucine, L-Valine, and L-Isoleucine, known as branched-chain amino acids (BCAA), are three of the nine essential amino acids. (Essential amino acids can’t be produced by the human body and must come from food).

Amino acids are the building blocks of proteins and are critical to many bodily systems. BCAAs, in particular, are crucial components in the muscle repair process – although scientists are still investigating the repair benefits of consuming BCAAs during endurance activities.


Vitamins are critical micro-nutrients that govern a vast range of human body functions.

Vitamin B complex is made up of eight vitamin Bs responsible for:

  • Metabolizing nutrients
  • Growth of red blood cells
  • Energy levels
  • Eyesight
  • Brain function
  • Digestion
  • Nerve function
  • Hormones and cholesterol production
  • Cardiovascular health

Vitamin C, also known as ascorbic acid, supports:

  • Cell protection
  • Blood vessels, bones, and cartilage health

Vitamin D support:

  • Regulation of calcium and phosphate levels
  • Bone and muscle health

Several other vitamins are necessary to make up a healthy daily diet. Learn more here.

Many manufacturers add vitamins into their energy gels. When you’re pushing yourself to the limit, it’s not a bad idea to also replenish micro-nutrients.

To caffeine or not to caffeine?

The benefits of this naturally occurring chemical compound are well documented, from muscle fatigue delay and improved nerve signal transmission to better mood and enhanced focus. However, it also has side effects such as upset stomach, frequent urination, insomnia, and dependence.

If you are a regular and heavy consumer of caffeine beverages, the effects of caffeinated energy gels might be negligible. In my personal experience, to get a real performance boost on race day, I had to cut off caffeine for at least 5-8 days before a race.

Nutritional value and how to read energy gel labels

Ingredients: Items are listed in order of predominance and in descending order.

Serving Size: The typical size of an energy gel is about 30g, but it might be bigger, especially if it’s an isotonic (meaning already been mixed with a good balance of water).

Calories per serving: An ideal energy gel should provide about 100 calories.

Total Carbohydrates: this is where the bulk of the energy is contained. A subset of this includes Total Sugars, which count sugars contained in natural foods within the gel, plus Added Sugars, which include concentrated sugars like maltodextrin or fructose.

Total Fat & Cholesterol – these have to be included on the label according to FDA regulations but are not really too relevant to the benefits of energy gels. Seeing 0 in these categories is a good thing most of the time.

Sodium – when you sweat, your body sweats out salt along with other electrolytes (like sodium and potassium). Many energy gels will naturally contain or add ingredients to help you replenish the lost electrolytes.

Protein – gels are not meant to be a steak dinner, but in some cases, they will contain BCAAs.

example nutrition label energy gel

Please carefully read nutritional and ingredient labels if you have food allergies or practice specific diets such as gluten-free or veganism.

Flavor – be kind to your taste buds

This is the most subjective component of your fuel plan but arguably the most critical.

I’m in the camp of “there are no tasty energy gels, only tolerable ones.” The digestive tract begins with the mouth, meaning your taste buds are part of the equation of whether an energy gel might cause gastrointestinal issues.

Gels can be sickeningly sweet and come in thick syrupy pastes. Not a winning, delicious combination. Consuming packages of gel one after another may cause sweetness fatigue – when you simply can’t imagine yourself eating another. And if you don’t select options that agree with your taste buds, nausea and even vomiting are not uncommon.

For example, to fuel a marathon PB attempt, you might need to eat upwards of six energy gels or more. That’s a lot of syrupy sugar water.

On race day, you will be going hard, and you will be tested physically and mentally. Take care of your taste buds and eliminate preventable discomforts such as bad-tasting fuel.

Honestly, we don’t have a lot of advice when it comes to flavor since, like we’ve mentioned, it’s highly subjective. But hopefully the following tips are helpful.

1. Start with your favorite foods. For example, if you like chocolate, there’s a good chance chocolate-flavored gels work for you. If you enjoy the tartness of citrus fruits, look for flavors based on orange or lemon.

2. Know your consistency preference. Some gels are thick syrups, some are lighter and watery, and some are like crushed jello. Use them on your workouts and see what agrees with you.

3. If you follow a clean diet, try energy gels that use natural ingredients. “Organic”, “all-natural”, and “from natural source” usually indicate goodies made by Mother Nature.

4. There are alternatives that are just as effective as energy gels. For example, honey and maple syrup have garnered many loyal followers from the professional rank to weekend warriors.


The energy gel package must be compact enough for whatever you will use to carry your race fuel. The packaging should also be easy to open and doesn’t create a mess. I would also avoid see through packaging as this may affect shelf life. Nothing is more annoying than struggling to tear open a sachet while fatigued or sticky fingers. Here are a few considerations.

Weight vs. the amount of carbohydrates – ideally, each energy gel sachet should weigh about 30g and provides 100 calories and 20g of carbohydrates. Extra weight slows you down. Cut weight where you can.

One-hand snap design – there are many interesting new packaging designs out there. Here’s one from 32GI. It’s really quite convenient when only one hand is required.

You can close it back up – some energy gels comes with a twist cap. You can take a few sips and close it again. Convenient and mess-free. Consume in smaller regular dosages to avoid over stressing the digestive system.


Last but not least, practice, practice, and practice. You can train your gut just like you train your legs, heart, and lungs. Don’t try anything new on race day you haven’t practiced using. Follow the simple guidelines above and begin planning and refining your energy gel strategy as you build up towards kicking ass on race day.