Simple Carbs Before a Workout: What to Eat and When
Nora FiermanYou know you need carbs before exercise. But "eat carbs" isn't very specific advice when you're standing in your kitchen deciding between oatmeal and a banana 45 minutes before a run.
The answer depends on something most athletes never think about. Not all carbohydrates behave the same way in your body. Simple and complex carbs digest at different speeds, hit your bloodstream differently, and are suited to different windows around your workout. Get the type right for the timing and you'll have steadier energy and fewer GI issues. Get it wrong and you'll either bonk early or spend your warm-up regretting breakfast.
Here's what the research says about simple carbs before a workout, when complex carbs are the better choice instead, and how to apply it to running, cycling, and race day.
What Makes a Carb "Simple" vs. "Complex"
Carbohydrates are classified by their molecular structure, which determines how quickly your body breaks them down. Simple carbs are made of one or two sugar molecules - think glucose, fructose, or sucrose - and digest fast, delivering a quick hit of energy. Complex carbs are longer chains of sugar molecules that take more time to break down, releasing energy more gradually.
This digestion speed is also reflected in the glycemic index (GI), a measure of how quickly a food raises blood sugar. High-GI foods (white bread, sports drinks, ripe bananas) spike blood glucose fast. Low-GI foods (oats, whole grains, legumes) raise it slowly and keep it more stable over time.
One important caveat: the simple-versus-complex label doesn't always predict GI accurately. White rice is technically a complex carbohydrate, but it has a high glycemic index similar to pure glucose. Fructose from fruit is technically simple, but digests more slowly than glucose. Classification matters less than the practical question: how fast does this food actually raise your blood sugar, and is that what you need right now? Fat content matters too. Adding fat to a carb source slows digestion regardless of whether the carb itself is simple or complex.
Why Simple Carbs Are the Right Choice Right Before a Workout
This is the core answer to "what carbs should I eat before a workout." For the window immediately before exercise, generally 15 to 30 minutes out, simple, fast-digesting, low-fat carbs are the better choice.
The reasoning is straightforward. Your body needs glucose available in the bloodstream quickly once you start moving, and simple carbs deliver that without requiring extended digestion time. Complex carbs, and carb sources with added fat, eaten too close to a workout are still being broken down when you start exercising, which can mean less available energy when you need it and a higher chance of GI discomfort from food still sitting in your stomach.
Research on glycemic index and exercise performance supports this distinction by intensity and timing. High-GI, low-fat foods are useful directly before, during, or after exercise to rapidly deliver carbohydrate while limiting how much volume sits in your gut, while lower-GI choices are better suited to your regular daily eating.
The Best Simple Carbs to Eat Right Before a Workout
Bananas — a ripe banana is one of the most reliable pre-workout simple carbs. Fast-digesting natural sugars, potassium for cramp prevention, and gentle on the stomach. Best eaten 15 to 30 minutes before starting.
Dates — concentrated natural sugar in a small, portable package. A couple of Medjool dates 20 to 30 minutes pre-workout deliver fast carbohydrates without much volume.
Honey — a tablespoon of honey is almost pure simple sugar, easy to digest quickly, and works well stirred into a small pre-workout snack or taken directly.
Fruit juice — a small glass of fruit juice 20 to 30 minutes before exercise is a classic, effective option. Liquid carbohydrates digest fast and double as hydration.
Sports drinks — formulated specifically for fast carbohydrate delivery and hydration together, carb drinks like Trailwind or Skratch are a convenient pre-workout (and mid-workout!) option, particularly in hot conditions where you also need to start hydrating ahead of fluid loss.
Pretzels or salty crackers — a small handful of pretzels or crackers delivers simple carbs along with sodium, which can be useful before a long or hot workout where you'll be sweating heavily. Low in fat and fiber, so they digest quickly without sitting heavy.
Plain potato or rice chips — similar logic to pretzels: low-fat, salty, fast-digesting carbohydrate. Popular with longer-distance runners and cyclists who want a savory pre-workout option instead of something sweet.
Saltine crackers with jam or honey — a classic, simple combination that pairs fast carbs with a little sodium. Easy on the stomach and easy to portion in small amounts before heading out.
White bread or a bagel — refined white flour is digested quickly due to its low fiber content, making a small piece of white toast or half a bagel a reasonable simple-carb option in the 30-to-60-minute window, especially for athletes who want something more substantial than fruit alone.
What About an Hour or More Before — or During Long Efforts?
The 15-to-30-minute window calls for pure fast sugar. But once you're an hour or more out from starting, or once you're well into a long endurance effort, the calculus changes. At that point, a little fat alongside your carbs isn't a liability. It can actually help sustain energy over a longer window rather than spiking and dropping quickly.
This is where a smoothie pouch like Neve's Boysenberry Beet fits. It combines banana and boysenberries for natural carbohydrates, plus beet-derived nitrates and electrolytes from sea salt and coconut. Because it contains coconut cream, it has fat content and digests a bit more slowly than a banana or a straight shot of juice, which makes it a better fit roughly an hour before activity, or as fuel during a long run, ride, or hike, rather than something you grab in the final 15 minutes before walking out the door.
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Neve's Boysenberry Beet pouch delivers natural carbohydrates from banana and boysenberries alongside beet-derived nitrates and electrolytes. With coconut cream for sustained energy, it's designed for about an hour before activity or for fueling during long efforts.
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When Complex Carbs Are the Better Choice
Simple carbs aren't always the answer. For the meal you eat two to three hours before a workout, and for your regular day-to-day eating, complex carbs are generally the better fuel source.
Complex carbohydrates digest more slowly, providing steady energy release rather than a quick spike and drop. This makes them ideal for the pre-workout meal, where you have time for digestion before you start moving, and for daily nutrition where stable blood sugar matters more than a rapid burst of fuel.
Good complex carb sources for the pre-workout meal: oatmeal, whole grain toast, brown rice, sweet potatoes, quinoa, and whole fruit eaten with its fiber intact rather than juiced.
A practical framework: two to three hours before a workout, eat a balanced meal built around complex carbs with some protein, like oatmeal with banana and nut butter, or rice with eggs and vegetables. Around the one-hour mark, a smoothie pouch works well to top off energy with some sustaining fat alongside the carbs. Then, 15 to 30 minutes before you actually start, switch to a pure fast-sugar option if you need one more boost, particularly for longer or more intense sessions.
Simple Carbs During Exercise: Why This Window Is Different Again
During exercise, particularly efforts over 60 to 90 minutes, fast-digesting carbs dominate, but the picture is more nuanced than the 15-minutes-before window. Your body's reduced blood flow to the digestive system during exercise makes complex carbohydrates and high-fat foods harder to break down efficiently mid-effort, which is part of why gels, chews, dates, and bananas are common in-race fuel.
But for longer efforts, over two to three hours, a smoothie pouch with some fat content, like Neve, becomes a reasonable and even useful option. The slight digestive slowdown from the fat provides more sustained energy release over a multi-hour effort, which is a different need than the rapid-fire glucose hit you want in the first 90 minutes or during a hard surge.
The general guideline for endurance exercise: 30 to 60 grams of simple carbohydrates per hour for efforts over 90 minutes, scaling up toward 60 to 90 grams per hour for longer or harder efforts. Using multiple carb sources together, like glucose and fructose combined, as found naturally in fruit, can improve absorption rates compared to a single sugar source alone.
Good Carbs for Runners Before a Race
Race-day nutrition follows the same simple-versus-complex principle, with one added layer: how far out from the start you're eating.
Two to three hours before the race: a complex-carb-forward meal. Oatmeal, toast, or rice with a banana. This tops off glycogen stores without sitting heavy when the gun goes off.
About one hour before the race: this is a good window for a smoothie pouch if you want something more substantial than a pure sugar hit. The fat content won't have time to cause issues but will help sustain you into the early miles.
Fifteen to thirty minutes before the race: a small amount of pure simple carbs. A banana, a few dates, or a small amount of honey or juice. This gives you an immediately available glucose boost right as you're warming up, without anything still digesting when the gun goes off.
During the race: fast carbs early on, with the option to bring in something more sustained, like a smoothie pouch, for efforts running past two to three hours.
Best Carbs for Running a Marathon
Marathon distance adds a few specific considerations beyond shorter races.
Carb loading in the 36 to 48 hours before a marathon, increasing complex carbohydrate intake to maximize glycogen stores, is well-supported practice for events of this length. This isn't about a single pre-race meal; it's about elevated carbohydrate intake across the day or two leading up to race morning.
On race morning itself, the same framework applies: a carb-forward breakfast two to three hours out, a smoothie pouch around the one-hour mark if desired, then pure fast carbs in the final 15 to 30 minutes. During the marathon, fast carbohydrates are essential from around mile four or five onward, with consistent intake every 30 to 45 minutes.
The Bottom Line
The question isn't simple carbs versus complex carbs, it's the right carb at the right moment. Complex carbs power your pre-workout meal and your daily nutrition. Pure simple carbs take over in the final 15 to 30 minutes before you start and during the early part of a hard effort. And carb sources with a bit of fat, like Neve, earn their place roughly an hour out or during longer efforts, where sustained energy matters more than an instant spike.
Get the timing and the food type right together, and your body has exactly the fuel it needs, exactly when it needs it.
🌿 Real, sustained fuel for the long haul.
Neve smoothie pouches combine whole-food carbohydrates with natural fat from coconut for sustained energy, built for about an hour before activity or for fueling through a long run, ride, or hike. Resealable, portable, and made for athletes who need fuel that lasts.
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