Energy gels: should you take them? And what to replace them with
Energy gels have become a reflex in running, trail running and marathons. A fast hit of carbs, easy to carry, ready in seconds. During intense efforts, it works.
The problem is the autopilot: one gel every 30 minutes, whatever the pace. On an easy run, it's pointless. Over time, it's often poorly tolerated. So the right question isn't "gel or no gel", but at what intensity a gel becomes useful.
What's in a gel
A standard gel delivers around 20 to 25 g of simple carbs: glucose, fructose or maltodextrin. They enter the bloodstream quickly, which supports intense efforts when the muscles draw heavily on their sugar stores.
That's exactly what makes it a good tool at high intensity, and a bad reflex at low intensity. On a slow run, the body runs mostly on fat. Feeding it fast sugar every half hour holds back precisely what the session is meant to teach it: using its own reserves.
When a gel is useful: above 80 % of max HR
Our benchmark is simple: a gel is a tool for efforts above roughly 80 % of your maximum heart rate. End of a race, final climb, surges, race pace on a long effort. That's where fast carbs make the difference.
And even then, there's a limit: no more than 90 g of carbs per hour, gels, drinks and food included. Beyond that, most stomachs can't keep up.
| Type of effort | Carbs per hour | Gel? | Recommended fuel |
|---|---|---|---|
| Long Zone 2 run | 5 to 20 g | No | BSE Zone 2: 1 pouch every 2 h |
| Tempo, threshold, strength | 20 to 45 g | Rarely | BSE Tempo: 1 serving per hour + real food |
| Ultra, long race, efforts above 80 % max HR | 45 to 90 g maximum | Yes, occasionally | Tempo + Zone 2 + real food, and gels on the intense sections |
Why more and more athletes are moving away from them
Three reasons come up again and again.
- Taste: over several hours, the constant sweetness becomes hard to swallow.
- Energy: doses taken too close together make blood sugar spike and crash, and mental clarity goes with it.
- Digestion: bloating, cramps, nausea. A sign the stomach is saturated.
What to replace gels with? Alternatives by effort
There isn't one alternative to gels, but one per intensity. The right choice depends on what your body is burning at that moment.
On a slow long run: a fat-based foundation
In Zone 2, the body runs mostly on fat. So the most consistent fuel is rich in fats: nut butters, nuts, or a purée like BSE Zone 2 (macadamia, MCT, salt). Dense, steady energy with no blood sugar spike, supporting the effort without shutting down fat burning.
At a sustained pace: drink and real food
When the intensity rises, carbs become useful. That doesn't mean you need gels: a drink like BSE Tempo (15 g of carbs and 600 mg of sodium per serving) and real food are enough. Banana, fruit purée, dates, salted potatoes: a single banana provides around 25 g of carbs, often better tolerated than a gel.
On the most intense sections: the gel, in its rightful place
Above 80 % of max HR, at the end of a race or on a long climb, the gel still has its value: fast, compact, easy to take. Used occasionally, on top of a stable foundation, and without exceeding 90 g of carbs per hour in total.
How to choose
Three questions are enough:
- What intensity? Below your aerobic threshold, no gel. Above 80 % of max HR, the gel becomes a tool.
- What duration? Beyond 2 hours at a sustained pace, you need regular carbs: 20 to 45 g per hour, up to 90 g maximum on the longest and most intense efforts.
- What do you tolerate? Test everything in training, at race pace. On race day, you discover nothing new.
A detail people forget: your teeth
Sugary and often acidic products, taken every 30 minutes for hours, expose your teeth to sugar and acidity, with less saliva to protect them during exercise. A simple habit: a sip of water after each dose. And one more reason not to make gels the default foundation of every run.
Conclusion: the gel is a tool, not a foundation
Switching products isn't enough. You have to switch logic. On a slow run, eat the way the body burns: fat, salt, very little sugar. When the intensity rises, add carbs in small, regular amounts. And the gel keeps its place where it's most useful: on efforts above 80 % of max HR, without exceeding 90 g of carbs per hour.
That's the logic behind the gel we're developing ourselves, designed for those intense efforts and not for the Sunday run.
To go further: what to eat during exercise: carbs per hour, what to eat before a race, sports recovery: what to eat after exercise, aerobic base training explained and the long Zone 2 run.