If you've ever felt your legs go heavy halfway through a long run, or wondered why some runners seem to hold up so much better than you, energy gels might be part of the answer. But they're not a one-size-fits-all solution, and using them correctly makes all the difference.
In short
Under 45 to 60 minutes: no gel needed. Beyond 90 minutes (half marathon, marathon, trail): aim for about 30 to 60 g of carbs per hour, or one gel every 30 to 45 minutes, up to 90 g per hour in ultras if your gut is trained.
Always take your gel with water, and test your products in training, never for the first time on race day.
Table of contents
Why does your body need fuel while running?
Your body stores energy as glycogen in your muscles and liver. For most runners, those reserves last about 60 to 90 minutes of sustained effort. Beyond that, without refueling, muscle fatigue sets in faster, focus drops, and your perceived effort climbs sharply.
That's where energy gels for running come in: by delivering fast-absorbing carbohydrates (and often key electrolytes), they help slow the progression of fatigue, keep your energy steady, and get you to the finish line in much better shape.
At what distance do energy gels become useful?
General rule: under 45 to 60 minutes of effort, your body doesn't need extra fuel mid-run. For a 5K or 10K at your usual pace, a good meal beforehand is plenty.
It's beyond 90 minutes of effort, and especially at the half marathon and marathon distance, that gels become a real performance tool. The longer the race, the more your fueling strategy impacts your result, and your enjoyment of the run.
| Effort duration | Gels needed? | Guideline |
|---|---|---|
| Under 45 min | No | Water is enough |
| 45 min to 1 h 30 | Maybe | Depending on intensity; 1 gel if needed |
| Over 1 h 30 (half, marathon) | Yes, recommended | 30 to 60 g of carbs per hour |
| Ultra, multi-hour trail | Yes, essential | Up to 90 g per hour, trained gut |
How many gels, and when?
Most gels deliver 25 to 30 g of carbs. For efforts over 90 minutes, the usual target is 30 to 60 g of carbs per hour, which works out to one gel every 30 to 45 minutes. Well-trained ultra runners go up to 90 g per hour, but that tolerance is built gradually.
- Your first gel: take it around the 45-minute mark, before you feel tired. Waiting for the wall is too late.
- Then, on a regular schedule: set an alert on your watch or tie your gels to the course aid stations.
- Caffeine: save caffeinated gels for the second half of the race or key moments, and test your tolerance in training.
Example for a 3:45 marathon
One gel at 45 minutes, then one every 35 to 40 minutes: about 5 to 6 gels in total, each with a few sips of water. Save the caffeinated gel for kilometre 30.
The biggest mistake runners make
A lot of people give up on gels after one bad experience (cramping, nausea, a gel that was impossible to choke down) and conclude that "gels just aren't for them."
The reality is that not all gels digest the same way. Texture, ingredients, sugar concentration, caffeine content or lack thereof: all of these affect how your body responds. It's worth taking the time to test different brands and formulas of energy gels and chews on your long training runs to find what works for your stomach and your performance.
A few brands worth trying
Good news if you're looking for natural options: several Canadian and Québec brands make high-quality gels with recognizable ingredients. Here are the ones our runners use most.
Also worth trying: if you prefer a drink format, Upika is a Québec brand that delivers running fuel as a drink mix. To see everything, browse our energy gels and chews collection.
How to practice your fueling strategy
Don't wait until race day to try your gels for the first time. Ideally, start incorporating them into your long runs 8 to 10 weeks before your event. Here's a progressive approach:
- Start with a solo test: try one gel during a moderate long run to see how your stomach handles it.
- Build gradually: add one more gel per long run, simulating race conditions (same time of day, same pace, with water).
- Track your observations: which gel? at what minute? how did you feel 15 minutes later? Keep a simple log.
- Arrive at your event with a confirmed plan: you'll know exactly what to take, when, and how much, with no surprises.
Don't forget the water
An often-overlooked point: a gel without water can cause digestive discomfort. Concentrated carbohydrates need to be diluted to be properly absorbed. Always take your gel with a good sip of water, never dry, and never with a sports drink that's already high in sugar.
To carry gels and water without thinking about it, a belt or vest makes all the difference: see our hydration accessories. And in hot weather, read our guide to hydration and electrolytes for running.
Frequently asked questions
Ready to find your gel?
Test different brands on your long runs: it's the only way to find what works for you. And if you're unsure, drop by our store and we'll help you build your fueling plan.
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