How To Carbo-Load Correctly (Including Which Carbs To Eat)

Ray Bass is the associate movement and wellness editor at mindbodygreen and a NASM-Certified Personal Trainer. She holds a degree in creative writing from the University of Pennsylvania, with honors in nonfiction.

As we discovered in an article last week, carbo-loading isn't for everyone. Unless you're an endurance athlete or competing in a race that will last over two hours, carbo-loading just isn't necessary.
But let's say you do meet those conditions—perhaps you're running your first or 15th marathon, competing in a Tough Mudder, or taking on an athletic feat of similar ferocity and duration. Well in that case, yeah, you should consider carbo-loading and seeking out expert advice before you do.
We went ahead and did that for you because the rules of carbo-loading are a bit counterintuitive (or at least, they were to me). Here’s how to properly carbo-load.
What are the best carbs for carbo-loading?
At this point, many of us know the basics of carbohydrates. Simple carbs spike your blood sugar; complex carbs are most slowly absorbed into our system, and are thus deemed healthier carbs. But carbo-loading turns the healthy carb notion on its head. When using carbs to prepare for a race, it's actually the simple, fiberless carbs that you want to eat—not the quinoa and buckwheats of the world.
"Generally, the best carb sources for loading are easily digestible ones," says Jaime Schehr, N.D., R.D. "Think sweet potatoes or pasta, white rice, and bananas. Carbs that are too high in fiber cause GI distress."
Amy Shah, M.D., echoes this sentiment, adding that, in her experience, avoiding wheat is wise for most people (race or no race). For anyone carbo-loading, she recommends rice as a better choice, especially if you're doing an ultramarathon or long race.
"Simple carbs without a lot of extra insoluble fiber are the way to go the night before a race," she says. "My ideal choices would be a sweet potato or even a regular potato. Knowing what we do about wheat, I would say it's not the ideal choice for most people. I would say 75% of the people I work with have some GI sensitivity to wheat."
So in short, the carbs that are most effective for carbo-loading actually aren't what we've been taught are the "healthiest" carbs. Stick to carbs with little to no insoluble fiber the night before a race—this will ensure that your glycogen stores are full and save you the stress of stomach issues in the morning.
When is the best time to carbo-load?
In terms of when you should consume your carbs, experts recommend doing so 24 to 48 hours before your event. This gives your body time to store them. Beware, though—eating carbs too close to a race could come back to bite you.
"Twenty-four to 48 hours is generally recommend for carbo-loading," Schehr says. "Carbo-loading a few hours before the event is not recommended, as the stomach may be full, and that could negatively impact your performance."
OK, 24 to 48 hours it is.
Reminder: Not everyone needs to carbo-load.
Before you start carbo-loading, it's imperative that you figure out whether you really should be carb-loading. While the consequences of doing so without needing to aren't catastrophic, pointless carbo-loading could jeopardize your fitness and health goals, whether you're racing or not.
We recommend abiding by across-the-board expert guidelines: If you're working out or competing for less than two hours, carbo-loading probably isn't for you.
"Remember, you don't need to carbo-load if you're doing an hourlong workout," Shah says. "In fact, only if you're working out for over two hours do you need to worry about this concept."

Ray Bass is the associate movement and wellness editor at mindbodygreen and a NASM-Certified Personal Trainer. She holds a degree in creative writing from the University of Pennsylvania, with honors in nonfiction. A runner, yogi, boxer, and cycling devotee, Bass searches for the hardest workouts in New York (and the best ways to recover from them). She's debunked myths about protein, posture, and the plant-based diet, and has covered everything from the best yoga poses for chronic pain to the future of fitness, recovery, and America's obsession with the Whole30 diet.