What is the best carb for athletes?

October 22, 2025 •

5 min read

Carbohydrates are the body's primary fuel source, and studies show that maximizing muscle glycogen stores through strategic carbohydrate intake can improve performance in endurance events by up to 25%. However, the "best" carb depends entirely on the athlete's specific needs, timing, and type of activity. This guide will explore how to select and time your carbohydrate intake to maximize athletic performance and recovery effectively.

Quick Summary

This article examines the types of carbohydrates and when athletes should consume them for optimal energy, training, and recovery. It provides guidance on strategic fueling with complex and simple carbs, covering pre-workout, intra-workout, and post-workout timing for different sports and activity durations.

Key Points

Timing is Crucial: Use slower-digesting complex carbs for daily energy and sustained fuel, but switch to fast-acting simple carbs immediately before, during, and after intense training or competition.
Choose the Right Carb for the Moment: Opt for whole foods like oats, quinoa, and sweet potatoes for foundational nutrition, and use rapid sources like bananas, dried fruit, or sports gels for immediate performance and recovery benefits.
Fueling for Endurance: Athletes in events longer than 90 minutes should consume 30-90+ grams of simple carbohydrates per hour during exercise to maintain energy levels and delay fatigue.
Prioritize Recovery: Immediately post-workout, consume high-GI simple carbs combined with protein (approx. 4:1 ratio) to rapidly replenish muscle glycogen stores and promote muscle repair.
Train Your Gut: Practice your fueling strategy during training to condition your gut to absorb higher carbohydrate quantities and prevent gastrointestinal distress on race day.
Individualize Your Plan: Factors like training intensity, sport type, and personal tolerance should guide your specific carbohydrate choices and quantities.
Carb-Loading is Event-Specific: Carb-loading is most beneficial for endurance events over 90 minutes and involves increasing carbohydrate intake 1-3 days prior. It is generally not necessary for shorter-duration activities.

Understanding Simple vs. Complex Carbs

The fundamental distinction in carbohydrate choice for athletes lies in their digestive speed and glycemic index (GI), a measure of how quickly a food raises blood sugar levels. Simple carbohydrates are digested rapidly, providing a quick burst of energy, while complex carbohydrates are digested more slowly, offering a sustained release of energy over a longer period. Both play a critical role in an athlete's diet, but their timing is key.

Simple Carbohydrates

These are fast-acting sugars found naturally in fruits, honey, and dairy, as well as in refined foods like white bread and sugary sports drinks. For athletes, simple carbs are beneficial for:

Quick Energy: Ideal for consumption right before or during intense, prolonged exercise to prevent fatigue.
Rapid Recovery: Post-workout, high-GI simple carbs can quickly replenish depleted muscle glycogen stores, which is crucial for athletes with multiple training sessions in a single day.

Complex Carbohydrates

Complex carbs are longer chains of sugar molecules found in whole grains, legumes, and starchy vegetables. They are a valuable source of steady energy for athletes and should form the foundation of their daily nutrition plan. Key benefits include:

Sustained Fuel: Provides long-lasting energy for endurance activities and supports daily training.
Nutrient Density: Whole-food complex carbs contain beneficial fiber, vitamins, and minerals that support overall health.

Optimizing Carb Timing Around Your Workout

The timing of carbohydrate intake is as important as the type consumed. Athletes can optimize their fueling strategy by matching the carb type to their training schedule.

Pre-Workout Fueling

2-4 hours before: A balanced meal with complex carbs, lean protein, and some vegetables is ideal. This allows for proper digestion and ensures your glycogen stores are topped up for the workout ahead. Good examples include oatmeal, whole-grain pasta, or sweet potatoes.
30-60 minutes before: A small, easily digestible snack featuring simple carbs is perfect for a quick energy boost. This is especially useful for morning sessions or intense workouts lasting over an hour. A banana, a granola bar, or a piece of toast with jam are excellent options.

Intra-Workout Fueling

For exercise sessions lasting longer than 60-90 minutes, such as marathons or long cycling races, consuming carbohydrates during the activity is essential to maintain energy levels and delay fatigue. Aim for 30-90+ grams of easily digestible simple carbs per hour, depending on intensity and duration.

Recommended sources: Sports drinks, energy gels, chews, or easily transportable whole-food options like bananas or dried fruit.
Consider hydration: During exercise, particularly in high-intensity activities, carb-electrolyte drinks can be more effective than water alone for maintaining fluid balance and fueling muscles.

Post-Workout Recovery

Rapidly replenishing glycogen stores after a hard session is critical for effective recovery, particularly for athletes with multiple sessions or competitions scheduled in a short window.

Immediately after (0-30 minutes): A combination of high-GI simple carbs and protein is best to maximize glycogen resynthesis and kickstart muscle repair. Chocolate milk is a classic example that provides an ideal carb-to-protein ratio.
1-2 hours later: A complete, balanced meal incorporating complex carbohydrates will continue the glycogen refueling process.

Comparison of Carbohydrate Sources for Athletes


Carbohydrate Source	Type	Best For	Glycemic Index (GI)	Key Nutrients	Notes
Oats	Complex	Pre-workout fuel (several hours out), daily staple	Low	Fiber, magnesium, B vitamins	Provides sustained energy, can be prepared in various ways.
White Rice/Pasta	Simple/Complex	Pre-competition fueling (with low fiber), post-workout recovery	High (white)	Carbohydrates	Highly digestible for rapid energy or glycogen replenishment; less fibrous options useful near events to avoid GI distress.
Sweet Potatoes	Complex	Pre-workout meal (several hours out), post-workout recovery	Low to Moderate	Vitamins A & C, potassium	Versatile option for sustained energy and nutrient intake.
Bananas	Simple	Pre-workout snack (30-60 min), during prolonged exercise	Low to High (ripeness matters)	Potassium, natural sugars	Convenient, easy-to-digest portable fuel source.
Energy Gels/Chews	Simple	During exercise > 60-90 min, intra-workout top-ups	High	Concentrated carbs, electrolytes	Designed for rapid absorption and quick energy.
Whole Grain Bread	Complex	Daily carbohydrate intake, pre-workout meal (not immediately before)	Low to Moderate	Fiber, vitamins	Sustained energy source for daily training needs.

Conclusion: Personalized Fueling for Peak Performance

There is no single "best carb for athletes"; rather, the optimal strategy involves a periodized approach that matches carbohydrate intake to an athlete's training schedule and intensity. The fundamental principle is to utilize complex carbohydrates for sustained, daily energy and to strategically deploy simple carbohydrates around workouts to meet immediate fueling needs and support rapid recovery. Factors like gut tolerance, individual preference, and specific sport requirements should guide your choices, with testing during training being crucial before competition day. The key is to understand your body's specific demands and to use both simple and complex carbohydrates as powerful tools to maximize energy, endurance, and performance. Ultimately, a food-first approach with high-quality carbohydrate sources is recommended, with supplements complementing dietary intake when needed.

How to Choose the Right Carbs for Your Sport

Your sport's demands dictate your carbohydrate needs. High-volume endurance athletes require a higher overall daily intake and more simple carbs during prolonged activity. Strength and team sport athletes need a balanced mix for muscle function and recovery from high-intensity bursts, though fueling during sessions may be less critical.

How to Structure Your Daily Carbohydrate Intake

Aim for a daily intake of 5-10 grams of carbohydrates per kilogram of body weight, adjusting for training volume and individual factors. Prioritize complex, nutrient-dense whole foods for regular meals. Around intense workouts, include simple carbs for quick fuel and recovery.

The Role of GI and Fiber

While GI is a useful concept, especially for immediate fueling and recovery timing, it is not the only factor. Many whole-food complex carbs have a low GI, providing steady energy, but athletes should limit high-fiber intake immediately before intense events to prevent potential gastrointestinal issues.

When to Consider Supplements

For exercise lasting over 90 minutes, supplements like sports drinks, gels, or chews can be necessary to meet high hourly carbohydrate needs (e.g., 60-90g/hr) that might be impractical to obtain from solid food alone. Supplements offer a concentrated and easily absorbable source of simple carbs during activity.

Gut Training for Carbohydrate Intake

Just like training your muscles, you can train your gut to tolerate higher carbohydrate intake during exercise. By gradually increasing carb consumption during training sessions, athletes can improve absorption efficiency and minimize gastrointestinal discomfort on race day.

Combining Carbs with Other Macronutrients

Pairing post-workout carbs with a small amount of protein enhances muscle glycogen synthesis and accelerates muscle repair. A carb-to-protein ratio of approximately 4:1 is often recommended for optimal recovery.

Conclusion: A Tailored Approach is Key

The most effective carbohydrate strategy for an athlete is not a one-size-fits-all solution but a personalized plan tailored to the timing, intensity, and duration of their activity. By understanding the roles of simple and complex carbs and periodizing intake, athletes can optimize their fueling and recovery to achieve peak performance. Start with a food-first approach, experiment with timing and sources during training, and use supplements strategically to meet your goals.

Frequently Asked Questions

No, simple carbohydrates are not bad for athletes when timed correctly. While sedentary individuals should limit sugar intake, athletes need fast-acting carbs before and during high-intensity exercise and immediately after for rapid glycogen replenishment and recovery.

The daily carbohydrate needs for an athlete can range from 3 to 12 grams per kilogram of body weight, depending on the training volume and intensity. For general training, 5-7 g/kg is a good target, while endurance athletes in heavy training may need 7-10 g/kg or more.

Carb-loading is typically not necessary for shorter events like a 5k. Your body's normal glycogen stores are sufficient. Focus instead on a balanced, carb-rich meal a few hours before and a small, quick-acting snack 30-60 minutes before the race.

For immediate post-workout recovery, high-glycemic carbs like white rice, white bread, and sports drinks are most effective for rapidly replenishing muscle glycogen, especially when paired with protein. Chocolate milk is a popular option that provides both carbs and protein.

Yes, many athletes use solid foods like bananas, dried fruit, or even rice cakes for fueling during exercise, particularly for long endurance events. It is important to experiment during training to ensure gastrointestinal tolerance.

The glycemic index (GI) is relevant but should not be the sole determinant of food choice. Athletes can use high-GI foods for fast fuel delivery around workouts and low-GI foods for sustained energy at other times. The food's context, tolerance, and timing are paramount.

To prevent gastrointestinal (GI) distress, practice your fueling strategy during training to improve gut absorption. Also, reduce high-fiber foods in the 24-48 hours before a major event and consider consuming multiple carbohydrate types (e.g., glucose and fructose) for better absorption.