Our Members Asked:
Energy Gels: What Are They Used For and Do They Contain Their Labeled Ingredients?

Answer:
What Are Energy Gels?
Energy gels, also known as carbohydrate gels, are easy-to-carry, concentrated sources of carbohydrates that can fuel endurance athletes during activities such as marathons, cycling, and triathlons. These gels help maintain stable blood sugar levels, reducing the risk of fatigue and improving performance during endurance activities (Baur, Eur J Appl Physiol 2021; Kozlowski, J Strength Cond Res 2021).
Research suggests that consuming energy gels before or during exercise can enhance intermittent endurance capacity — the ability to sustain high-intensity bursts of activity with short recovery periods (Phillips, Eur J Appl Physiol 2012). Additionally, some people with diabetes use energy gels to stabilize blood sugar levels during episodes of hypoglycemia (low blood sugar) (Bhaskarabhatla, Compr Ther 2005).
Do Energy Gels Contain the Carbohydrates They Claim?
Independent testing of eight energy gel brands popular in 2024 revealed that not all products contain the carbohydrate levels stated on their labels. While seven of the tested products contained at least 85% of their stated carbohydrate content, one product contained only 28%, and this was found to be a consistent problem with other energy gels by the same brand (Tiller, Int J Sports Nutr Exer Metab 2024).
Sign in as a member for details, including brands tested and the differences in measured vs. labeled amounts of carbohydrates in the tested energy gels. Also learn about possible side effects of energy gels.
Why This Matters for Athletes
For athletes who rely on adequate carbohydrate intake for sustained performance, choosing a reliable energy gel is essential. Under-delivery of carbohydrates can lead to early fatigue, muscle cramps, and decreased endurance — all critical concerns for long-distance runners and cyclists (Lodge, Nutrients 2023).
Final Thoughts: Are Energy Gels Worth It?
Energy gels can function as a convenient sports nutrition tool that might help improve performance during endurance activities when chosen wisely. If you use them for marathon training, cycling, or triathlons, ensure you're selecting brands that consistently deliver their promised nutrition.
Join today to unlock all member benefits including full access to all CL Answers and over 1,400 reviews.
Join NowAlready a member? Sign In Here.
Join now at www.consumerlab.com/join/
Edward22197
March 07, 2025I've been using GU gels for about five months now. Previously, I avoided carbs before endurance training. Now, I run faster and I enjoy running so much more. I can't detect a caffeine effect.
Reply to this post…
stephen22109
March 01, 2025Former runner who used GU and on long runs they definitely helped me. Lately when biking in gym I have used Maurten and while more expensive they taste less sweet to me so I like that. Whether they help me with hard biking remains to be seen, but since I generally do the bike in the morning in fasting state I figure having a little boost for short duration hard biking can’t hurt. Ultimately my personal opinion is that these products generally benefited me on long duration events.
Reply to this post…
Charlotte22107
March 01, 2025I've been using GU gels since 1999. Two words: they deliver. Some flavors are caffeinated, some not--Caramel Macchiato is equal to a cup of coffee--so you can choose between just calories (all have amino acids and Vits C and E) and those with a caffeine punch. I don't like all the flavors, but Vanilla, Sea Salt Caramel, and Cara Macchiato are unrivaled classics.
Reply to this post…