TLDR: Are energy gels bad for you?
Not if you’re an endurance athlete. Despite what you’ve heard, energy gels are not bad for you when used appropriately in training and racing. If you’re running, cycling, or swimming for hours a week, your body burns through glycogen and fast-absorbing carbs like gels help maintain energy, support recovery, and reduce the risk of injury. The real problem? Applying public health messages about sugar and “ultra-processed food” to high-performance bodies. This article breaks down the science behind sugar, performance, and why gels are tools, not toxins.
Amira wasn’t obsessive. She trained hard, ate well, but she kept some sweets and a gel or two in her desk to help fuel post work sessions.
But the comments chipped away.
“Sugar again?”
“You actually eat those things?”
“Have you read Ultra-Processed People? That stuff’s poison.”
One day a gel wrapper fell out of her bag. Someone held it up like a sticky biohazard.
The drip-feed of judgment about sugar, health, “eating clean” wore her down. She started second guessing her fuelling, cutting back on carbs, what good was all this training if her health was going to be compromised?
That night, her coach messaged:
“You’re training for an Ironman and every blood test you’ve had from your GP looks great. You’re training to perform. Fuel like it.”
It was the reminder she needed.
Let’s say this clearly: public health advice is not the same as performance nutrition.
Most dietary guidelines are written for the average person, someone who sits most of the day, maybe exercises a few times a week, and is trying to reduce chronic disease risk.
If that’s not you, if you’re regularly logging double-digit training hours, then fuelling your body like you’re sedentary isn’t healthy. It’s harmful.
Sugar, in this context, is not “junk.” It’s glucose, maybe fructose. And these sugars are what your muscles need when you’re riding, running, swimming, or rowing for hours.
Sugar on its own doesn’t cause type 2 diabetes.
What causes problems is:
Eating too much energy overall
Being inactive
Carrying excess visceral fat (fat around the organs)
Having a low-quality diet over time
For more on the science behind this I’d highly recommend this article by expert in diabetes and all round nutrition hero Dr. Nicola Guess
As Dr Guess explains, our bodies can handle sugar well when muscles are active and you are using a ton of it! You know like during training for endurance sport. That’s literally what those carbs are for.
Let’s be clear about the context here.
A gel mid- long run isn’t a donut on the sofa.
When you’re training, that sugar:
Spares glycogen so you can go longer
Supports blood glucose to avoid fatigue
Helps you recover faster
Reduces injury risk by maintaining energy balance
During exercise, your body burns sugar rapidly. It’s not stored as fat. It’s not raising insulin in harmful ways. It’s literally keeping you moving.
Are energy gels bad for you during exercise?
Not when they’re being used to fuel endurance training.
Yes, sugar during training is fine.
But your diet shouldn’t be only sweets and processed snacks. Its really important as athletes we also take care of the boring nutrition fundamentals to keep us healthy and performing well. We all want to be in this sport for as long as we can and keeping healthy will help us to do that.
So between sessions, nutrient quality matters.
You still need:
Fibre from fruit, veg, and wholegrains
Micronutrients for immunity, bone health, recovery and more!
Protein to support muscle repair and adaptation
Healthy unsaturated fats to support hormone production and reduce risk for chronic disease
Instead of obsessing over whether sugar is “bad,” ask:
When used the right way, energy gels are not bad for you. The fear around sugar often comes from public health advice aimed at sedentary populations, not people training 6–15 hours a week. If your body is regularly depleting glycogen through training, fast-acting carbs like gels can be exactly what you need.
Paul is a sports nutrition consultant and educator with a PhD in Nutrition and Exercise Science. With over a decade of experience, Paul specialises in optimising performance and recovery for endurance athletes through evidence-based strategies. As a lecturer and researcher, Paul has published in peer-reviewed journals and worked with athletes, sports teams, and organisations to achieve peak performance.
