Maximize Performance: Understanding Carbohydrate Loading

Are you preparing for an endurance event? Whether you’re a long-distance runner, cyclist, swimmer, or triathlete, your performance depends heavily on your body’s stored energy—specifically, muscle and liver glycogen. When these stores run low, fatigue sets in, limiting your ability to sustain effort. That’s where carbohydrate loading, or glycogen supercompensation, comes in.

What Is Carbohydrate Loading?

Carbohydrate loading is a dietary strategy designed to maximize glycogen stores in the muscles and liver before prolonged exercise. By increasing carbohydrate intake in the days leading up to competition, athletes can extend their endurance and delay the onset of fatigue during long-duration events.

Stored carbohydrates (CHO) are a vital fuel source, especially as exercise intensity rises. Since glycogen reserves are limited, boosting them through strategic nutrition can make the difference between hitting the wall—or crossing the finish line strong.

Who Should Carb Load?

Carbohydrate loading is most beneficial for athletes participating in continuous, high-energy events lasting longer than 90 minutes, such as:

• Long-distance running
• Swimming
• Cycling
• Triathlons
• Cross-country skiing

Athletes in sports involving repeated bursts of high intensity—like soccer, lacrosse, or tournament tennis—may also benefit from this approach to sustain performance throughout long competitions.

How to Carb Load: Two Common Methods

1. The Classic Method

The traditional carb-loading strategy starts about one week before competition:

• Days 1–3: Glycogen depletion through intense training and low carbohydrate intake (50–100 g/day).
• Days 4–6: A carbohydrate-rich diet (70% or more of total calories from carbs) combined with reduced training intensity.

This approach can significantly boost glycogen stores but requires careful planning and recovery time.

2. The Evolved Method (Preferred)

Modern athletes often use a simpler, more practical version:

• Increase carbohydrate intake to 8–10 g/kg body weight per day for 2–7 days before the event.
• Pair this with 1–2 days of reduced exercise to allow glycogen to accumulate.

For a 150-pound (68-kg) athlete, that equals roughly 400–700 grams of carbohydrates per day—spread across meals and snacks.

Tips for Effective Carb Loading

• Focus on high-quality carbohydrates such as oats, rice, pasta, potatoes, fruits, and whole grains.
• Include moderate protein and limited fat to avoid digestive discomfort.
• Hydrate well—each gram of stored glycogen binds with about 3 grams of water.
• Avoid trying carb loading for the first time on race week; practice during training to find what works best.

The Bottom Line

Carbohydrate loading is a proven way to maximize endurance and delay fatigue during long-duration events. When done correctly, it helps you perform at your best by ensuring your body has the energy it needs to go the distance. Plan ahead, fuel smart, and give your glycogen stores the boost they need to power you across the finish line.