Dial Your Race-Day Nutrition

Gels, chews, bars, “real” food—there are seemingly infinite choices when it comes to race-day nutrition. Here’s how to make sense of them.

When it comes to undertaking your first (or 50th) trail race, figuring out your nutrition plan can be just as intimidating as the training itself.

It is generally accepted that, when running, your body holds roughly 90 minutes’ worth of glycogen, or carbohydrate, stores. Running out of glycogen induces a sort of brain-fogged stumble, where your arms and legs are heavy and uncoordinated and the smallest incline feels like a mountain. (You may know this as “the bonk.”) In other words, if you’re racing 90 minutes or longer you’ll require some sort of caloric intake to keep you on top of your game.

The problem is, it seems there are as many options for running nutrition as there are for shoes, socks and clothing combined. Every running store has a cornucopia of gels, chews, drink mixes, bars and other goodies right next to the cash register. What’s more, every runner has unique individual fueling needs; what works for one runner may not work for another. Here’s how to go about making sense of all the options.

1. Experiment

Figuring out the approach to nutrition that works best for you is as simple as trying various foods and nutrition products until you find what you like.

“It’s important to try lots of different things—gels versus chews versus solids; which flavors work; which brands and consistencies work—so you can figure out what works best,” says Kurt Decker, the general manager of Minnesota’s Twin Cities Running Company and a veteran of over 50 ultramarathons. “The beauty of nutrition products is you can buy them in tiny, individual-serving quantities so you have the opportunity to test them all out.”

It is important to find not only your favorite option, but also a go-to backup. “Sometimes that source of calories that normally works for you just doesn’t—[because] it’s hot out, your stomach doesn’t agree, whatever—and it’s important to have something else that will work in that case,” Decker says.

2. Consider the event specifics

Simply put, the longer and slower you run, the more solid food your body will crave and be able to process. In races that will only last a couple of hours—say a half-marathon on trails—a few gels or servings of chews with simple sugar might suffice, but for longer races and ultramarathons, more fat and protein will be needed as your body uses a slower-burning gear.

Moreover, you tend to be running faster in a shorter race, and your body might not be able to process solid food as well; when you start running slower in an ultra, however, your stomach can better digest and absorb solid, calorie-dense food.

“When I’m running fast, I need something that’s really light and easy for the body to break down, and something like a Clif Bar might not do that,” Deckers says. “But in a long ultra, you can take some heftier foods because your body is burning and processing at a different rate.

“I’d never in a million years think of chomping on a Clif Bar during a marathon,” he adds. “But when I ran in the Grand Canyon, solid food tasted great and I was moving slowly enough that I wasn’t worried about my stomach revolting on me.”

3. Know your options

Gels and chews

Designed as a pre-packaged quick hit of 100 calories of primarily simple carbohydrates, gels are one of the simplest ways to measure the recommended consumption of 200 to 300 calories per hour during an ultra. They’re also easy to digest, which make them a good option for shorter races where you’re moving faster.

The downside can be their consistency; many runners’ stomachs don’t handle the viscous, sugar-heavy recipes well, especially over longer distances. Some brands are producing “whole-food” gels, with ingredients such as blended fruit, which you may find easier on the stomach.

Likewise, chews can provide some quick energy in a more solid form. “When you’re in that half marathon-and-under distance, I think gels and [chews] and those types of things work best, usually just with water,” Decker says. They can also work for longer distances, either alone or as a supplement, depending on the runner.

Solid food and “real” food

Many sports-nutrition brands manufacture solid foods, such as bars or wafers. (Clif recently turned some heads by producing packets of blended whole foods, including pizza and sweet-potato flavors.) These options are designed to give you more well-rounded nutrition in a form that is still somewhat easier on the stomach than, say, an actual slice of pizza.

When you’re moving slow enough during a long race, however, sometimes “real” food is the best option. Aid stations late in 100-mile courses frequently offer such options as grilled cheese, PB&Js, or—yes—pizza, since runners who have been moving that long can often process nearly anything.

“Some of those [solid] foods are richer in calories, and they have fat or protein,” says Decker. “Not only are they more calorie-dense, but they have nutrients your body needs when you’re going longer.” He compares fat- and protein-rich foods to slow-burning wood, and gels or chews to kindling: “If you’re going to keep the fire going for longer, you need to have a variety of types of wood.”

The catch with whole foods is that it can be difficult to push yourself to a point in training where you crave, or can digest, solid foods. Often your first time trying solid food mid-run will be during a race. If something looks appetizing, listen to those cravings!

Liquid calories

More than simple (and sugary) sports drinks, many drink mixes now feature complex carbohydrates and formulas designed to be friendly to dicey stomachs. They serve the dual purpose of providing quick-hit calories during shorter races, when solid food isn’t necessary, and filling in as a main calorie source for people whose stomachs simply can’t take anything remotely solid, even gels, during longer races.

“The advantage [with liquid calories] is that you have easier digestion, and there isn’t the texture of gels that some people are repusled by,” says Decker. “Most people can drink back anything, to a degree.”