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What’s an Energy Gel? The Gooey Elixir that Endurance Athletes Can’t Live Without



Here’s the simple and classic definition of an energy gel: it’s typically a carbohydrate-rich, gel-like substance conveniently packaged to replenish lost calories and nutrients during exercise.

Yet, with the advancement in nutritional science, the uniqueness of individual athletes, wide-ranging endurance disciplines, and personal tastes, we are seeing a fast-growing variety of energy gel options in the market.


Today, let’s stick to the basics, talk like a layman, and just go over some prerequisites for an effective energy gel.

For glycogen replenishment

Carbohydrates are the primary fuel in endurance sports, especially at higher intensities. The macro-nutrient is stored in our skeletal muscles and liver in the form of glycogen, and our body can only store a limited amount.

To maintain optimal anatomical functions and avoid slamming into the dreaded “wall“, glycogen must be replenished, and that’s where energy gels play a role.


It’s essentially concentrated sugar water

Putting all the fancy science and marketing aside, the most important function of energy gels is delivering simple sugars such as glucose and fructose, which can be quickly converted into glycogen. Many energy gels do not contain protein, fiber, and fat to enable quick digestion.

(We know, we know…there are many fat-as-fuel athletes out there, but for the sake of providing a simple intro, we’re sticking with the more traditional gels here.)

How much energy do energy gels have?

Most energy gels provide between 20-30g of carbohydrates in a 100-calorie sachet. Let’s use marathon running as an example, and please be reminded that no two athletes are the same.

A relatively fit runner can store between 90-120 minutes worth of glycogen going at marathon to near lactic threshold pace.

Here’s a good starting point. Consume 1g of carbohydrate per kg of body weight per hour. Meaning a 60-kg athlete should take in 60g of carbohydrates each hour, about 2-3 energy gels. Don’t forget to test it out during training for a more precise and customized fueling strategy.

On-the-move convenience

Last but definitely not least is packaging. An energy gel must be compact and lightweight enough to fit in various pockets, belts, packs, and vests. Grabbing the sachet, tearing it open, and sucking down the gel should be seamless since athletes move at fairly high intensity while refueling. Extra physical and mental efforts exerted can make a difference when every minute counts.

When selecting an energy gel for your next challenge, remember to check the following:

  1. Does it have the right carbohydrates for fast glycogen conversion? Is it easily digestible?
  2. Does it pack enough carbohydrates and calories?
  3. Does it fit in your fuel-carrying gears? And is the packaging designed for easy consumption at race effort?

We hope you find this brief energy gel introduction helpful. Please leave a comment and let us know your thoughts.







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