There’s nothing like a long run for bringing out your mind’s deepest thoughts. Why am I here? What is the meaning of life? Could I eat candy instead of this gel? 

Unfortunately, you’re on your own with the first two. But there is scientific evidence to help determine your midrun fuel.

If you’ve ever heard someone say, “sugar is sugar,” they’re only kind of right. Yes, all simple carbohydrates have the same number of calories per gram (four), and all provide fuel that your body can use quickly. But there are significant differences, especially in the way your body digests them, explains Patrick Wilson, Ph.D., RD, an assistant professor in Old Dominion University’s Human Movement Sciences department. 

In 2015, Wilson authored a review of studies published in the Journal of Strength and Conditioning Research, which found taking in more than one type of carbohydrate (like glucose and fructose) could speed absorption of the fuel and lower your risk for GI misery. “Essentially your intestines have a maximal rate of absorption for specific sugars because the intestinal protein transporters can be saturated or maxed out above a certain rate. That’s a bad thing because it can lead to carbohydrate sitting in the gut, which is likely to cause GI symptoms and decrease performance,” he says, adding that anyone taking in more than 50 grams of carbohydrate an hour should be actively working to mix things up. It’s recommended to consume 30 to 60 grams of carbs per hour on runs 60 minutes or more. 

“Most sports foods provide different sources of carbohydrates, which for longer races or events, results in the body using different metabolic pathways to convert carbohydrates to sugar for fuel,” says Stevie Smith, a DC-based registered dietitian and five-time Ironman finisher. She adds, “Beyond that, products such as Clif Shot Blocks or Gu Chomps offer the electrolytes you need, like sodium, potassium, and magnesium, that candy doesn't.” 

Candy manufacturers, however, aren’t thinking about these things. In fact, they’re not thinking about athletes at all when they build recipes. And that may result in unintended consequences for marathoners who chug Skittles midrace. “We need to be mindful of what else is in the candy,” says Dina Griffin, R.D., a board-certified sports dietitian who works with athletes at e-NRG Performance in Boulder, Colorado. Things like artificial colors, preservatives and—in the case of Skittles—hydrogenated palm oil, can be a shock to the system.

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But if you practiced with candy and felt okay in your training runs you may be in the clear (as long as you replace your electrolytes in some other way). “If you wish to train with candy, I'd recommend first looking at lower fat or fat-free candy options, especially if working out at higher intensities to prevent GI distress,” says Smith. “In general, look for the simplest list of ingredients to get the benefit of the quick energy from the simple sugars without the risk of potential ill effects.”

There are elite athletes who use candy to fuel and live to talk about it. Ultrarunner Clare Gallagher bought a 1.9-pound tub of Sour Patch Kids before her victorious assault on the Leadville 100 last year. She went the candy route in part because it was cheaper than buying sports-specific chews, but also because she wanted something her crew could enjoy too.    
 
For candies made mostly from sugar (like Jolly Ranchers or We may earn commission from links on this page, but we only recommend products we back), Wilson advises a one-for-one calorie swap with your traditional sports nutrition. Bars like Snickers or Three Musketeers get more complicated. Since a fair portion of the calories come from fat (9 calories per gram), not carbs (4 calories per gram), you’ll need to figure out the exact number of carbohydrate calories the bar packs and use that number to figure out how much to eat. “You’d have to consume more calories of that candy to get the same amount of carbohydrate. That may be fine during an event like ultramarathon in which the average intensity is lower, but people tend to have more digestive issues with foods that contain substantial amounts of protein and fat during higher-intensity events like a half or full marathon,” says Wilson. 

Of course, there’s one other drawback to using candy instead of gels: Having it around the house is infinitely more tempting than having a packet of gels in your pantry. If you think you’ve got the self-restraint to keep Twizzlers on hand for training runs, go for it. But if you might find yourself indulging during marathon Netflix sessions, not marathon training sessions, be very, very careful. 

Want to try it? Here’s what fueling with candy might look like for a variety of distances. 

For runs or races shorter than one hour: Sorry, you probably don’t actually need any candy. If you want a sugar boost, consider swishing a carbohydrate solution, like Gatorade, then spitting it out. Research has shown that just tasting the sugar can give you a jolt of energy. 

For runs or races between one to two hours, a 2014 review of studies published in Haribo Gummy Bears recommends taking in 30 to 60 grams of carbohydrate per hour. This is what that looks like in candy form. 

1/4 cup We may earn commission from links on this page, but we only recommend products we back
Twizzlers 
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6 rolls of Smarties 
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For ultra-distance events, you may be able to consume products with more fat in them, since you generally run at a slightly slower intensity, says Wilson. But don’t forget to try them in training first. Still, it’s important to keep a close eye on the number of calories from carbohydrates each option provides. For example, a Snickers bar has 250 calories, but a large portion of those calories come from fat, not carbs. “That extra fat is basically providing calories without any likely benefit to performance,” says Wilson. If you were really craving a Snickers at mile 80 of a 100-mile race, it would be fine to eat one, but you’d need to also consume a gel or some other source of carbs within the hour to ensure you were getting enough quick-burning fuel. 

How many grams of carbohydrate you need can range from 40 to 110 grams per hour depending on your size, age, and your exercise intensity. For clarity’s sake, these recommendations are for 60 grams of carbohydrate per hour, which Wilson considers to be on the aggressive side, but not unrealistic for someone attacking an all-day event.

It’s also important to note that all of the fat-free options listed above would also work in ultra-distance events, and would carry less chance of gastric misery. But if you do want to fuel with chocolate, here are a few options.  

1.5 Three Musketeers
This has more carbohydrates per bar than a Snickers, so it may feel like less of a gut bomb. Still, there’s enough fat that you need to practice consuming these before race day. 

24 Flipz Chocolate Covered Pretzels 
Three servings (a serving is only eight pretzels) provides exactly 60 grams of carbs, plus fat and salt too—which every ultrarunner craves (and needs) late in a race. 

1 3/4 pack of M&Ms
They melt in your mouth, and possibly in your pack. Still, they’re loaded with sugar, and if you struggle with chewing and running, you can plop a few on your tongue and slowly let them dissolve.