For intense efforts over 90 minutes, carbohydrates aren’t optional. They are fuel for your body, keeping glycogen levels from crashing so you don’t hit the dreaded bonk. That’s where sports fuels—energy gels, drinks, and bars—come in.
But what’s the difference between these fuel types? And which one should you use? Let’s break it down.
New to this? Read our Fueling Guide.
Energy Gels
What They Are:
Energy gels are small sachets of highly concentrated simple sugars, sometimes with added electrolytes or caffeine. They deliver quick carbohydrates with minimal weight or bulk.
How to Use:
Tear the tab of the sachet just enough for the gel to come out—no need to rip the tab all the way off (with practice, you can do this with your teeth). Place your mouth over the opening, squeeze the gel, and swallow the contents. Follow with a swig of water.
Things to Watch Out For:
Always take gels with water. They are highly concentrated and, without water, the carbohydrates won’t absorb well.
When to Use Gels:
Energy gels are perfect when you need lots of fuel, but don’t want to carry lots of heavy fuel bottles. For example, in an ultra-trail race where you can get water at aid stations, or for long training rides where you’ll refill water at spigots along the way.
They’re also ideal when you want hydration and fueling separate. For example:
- If race day is colder than expected, you may not need to drink much. With an energy drink this would result in either underfueling or overhydrating (and lots of extra pee breaks or feeling sick from too much fluid in the gut). But, with gels, you can get carbohydrates independent of fluids.
- If it’s hotter than expected, you’ll be glad your bottle holds plain water rather than a carb-heavy mix. You can drink as much plain water as needed without overfueling.
Energy Drinks
What They Are:
Energy drinks are carbohydrate-rich beverages. They almost always include electrolytes to support hydration.
How to Use:
Mix the powder with water before drinking. Consuming the powder dry can alter gut osmolality and trigger GI distress.
Things to Watch Out For:
Not all “energy drinks” are built for performance. Many use sucrose as their main carbohydrate source, which is not as readily absorbed as maltodextrin and can cause upset stomach. Many also overdo certain electrolytes—especially magnesium—which can upset your stomach.
When to Use Energy Drinks:
Energy drinks are the best choice when you want to fuel and hydrate simultaneously. You won’t have to remember to take a gel since the fuel is mixed in with your fluids.
They’re also great for precise carbohydrate dosing. It might require some math, but you can calculate how much powder to add to your bottle to get the exact amount of carbohydrates you need. This is especially useful for gut training when you want to gradually increase carb intake to improve tolerance. Gels can’t be easily portioned like this, and once opened, they’re nearly impossible to reseal.
Energy Bars
What They Are:
Energy bars pack carbohydrates into a compact, chewable form. For endurance sports, it’s important to choose bars that don’t contain fiber, protein, or fat—these slow digestion.
How to Use:
Just eat it. Chew thoroughly to aid digestion.
Things to Watch Out For:
Many “energy bars” are snack bars in disguise. They often contain fiber, protein, or fat, which slow digestion and delay energy release. Having solid foods in the gut can cause discomfort, especially during high-impact sports like running. Hard or sticky textures can also be tough to chew while breathing hard.
When to Use Energy Bars:
For high-intensity endurance sessions, gels and drinks are usually the better choice. However, athletes sometimes crave a solid to chew on. The texture can also be a welcome break from liquids and gels. In this case, properly formulated bars can be used.
Note: Bars with fiber, fat, or protein, such as the Nduranz Training Bar 30, should be used for low- to mid-intensity sessions. Choose Nrgy Juice Bar 22.5 or Nrgy Chew Bar 22.5 for fueling high-intensity sessions.
Which Fuel Type Is Best?
Think of sports fuels like tools—each has a specific purpose. The “best” choice depends on your session conditions and personal preference.
Most endurance athletes use a combination of gels, drinks, and bars to meet their fueling needs. This flexibility lets you adjust carbohydrate and fluid intake for intensity, temperature, and convenience—and it helps prevent “flavor fatigue” over long sessions.
Whatever type of fuel you choose, test it in training first. That way, you’ll know exactly how your body reacts and avoid surprises on race day.
👉 Not sure how much to fuel? Try our Fueling Calculator.