SPORTS GELS - WHAT'S ACTUALLY IN THEM? - Skyrunner® World Series

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Gels are athletes most favored form of fuel during a race. But what is it in these small packs of power that gives us so much energy? Gels differ from product to product and sometimes, athletes take them not knowing what they are made of or if the product they chose has the best composition for them. So, rather than taking a stab in the dark, here, the nutrition experts at PROZIS explain what you’re likely to find in your energy gels and the effects these ingredients will have on your skyrunning performance.

Buff® EpicTrail Alexis Berg

Buff® Epic Trail
©Alexis Berg


Energy gels are a portable and convenient way to enhance performance during a race. Your body uses carbohydrates as its major fuel when racing so the main goal of sports gels is to provide carbohydrates that are rapidly digested and absorbed in your bloodstream to replenish carbohydrate stores that are depleted (for each sachet of gel you get ~25g of CHO).


Usually, the main ingredients are maltodextrin and sugars like fructose, a very rapidly oxidized carbohydrate mix. Besides that, gels have very little, or no, fat and protein, so these do not interfere in carbohydrate absorption.

Maltodextrin can also be found in gels – a starch-based ingredient widely used in sports drinks and other food products. It is obtained through the hydrolysis of starch from sources such as corn, rice, or potato, where the starch is broken down into smaller pieces, resulting in shorter chains of sugar molecules composed by glucose units.

Fructose is a simple sugar that can be found in many fruits, vegetables, and honey. It’s a monosaccharide that is absorbed and then turned into glucose in the liver to be metabolized.

Besides that, some energy gels may have caffeine or electrolytes. Caffeine is a stimulant with proven benefits for endurance performance that improves cognitive function, vigilance and alertness and reduces the perception of fatigue during exercise.

Electrolytes are useful to replace large sodium losses that occur during the race and for the post exercise rehydration.


It depends on how quick you race. The higher the intensity of the exercise, the more carbohydrates your body consumes. One good strategy is to remember these recommendations for the ingestion of carbohydrates during a race:

  • 30g CHO/h if you are running 1-2h ~ 1 gel per hour.
  • 60g CHO/h if you are running 2-3h ~ 2 gels per hour.
  • 90g CHO/h if you are running more than 2,5h ~ 3 gels per hour.

Besides gels there are other valid options like sports beverages or sport bars rich in carbohydrates. There is no one rule fits all, so every athlete has to know which product works best for them. Most important is know that timing is key – knowing when to take each type of product (before, during or after the race) is truly important since a product that works for you before may not be so easy to transport and take during the race.

PROZIS sports gels skyrunning nutrition