Cycling Glycogen Calculator

Glycogen is the stored form of carbohydrates in your muscles and liver. It's the primary fuel source for high-intensity cycling efforts. When glycogen stores are depleted, performance drops dramatically—a condition known as 'bonking' or 'hitting the wall.' Proper glycogen management is crucial for optimal cycling performance, especially during longer or more intense rides.

Our calculator uses scientifically validated formulas based on body composition, training status, and exercise intensity. While it provides a good estimate, individual variations in metabolism, gut absorption, and training adaptations can affect actual carbohydrate needs. We recommend using the calculator as a starting point and adjusting based on your personal experience.

The amount varies based on ride duration and intensity. For rides under 60 minutes, your stored glycogen is usually sufficient. For 1-2 hour rides, aim for 30-60g of carbs per hour. For rides over 2-3 hours, 60-90g per hour is recommended. Very intense or long rides may require up to 90-120g per hour, which typically requires training your gut to handle this amount.

The simple calculator requires minimal inputs (gender, age, height, weight, and ride details) and makes reasonable assumptions about your body composition and physiological factors. The elaborate calculator allows for detailed customization including body fat percentage, activity level, body type, and precise performance metrics for maximum accuracy.

While optimized for cycling, the calculator's principles apply to other endurance sports. However, the muscle recruitment patterns and energy demands differ between sports, so the results will be most accurate for cycling activities. For other sports, consider the results as a general guideline rather than a precise recommendation.

Common signs include a sudden drop in power output, heavy legs, difficulty maintaining pace, mental fatigue, inability to concentrate, irritability, and feeling unusually hungry or empty. These symptoms are often referred to as 'bonking' and indicate that your carbohydrate stores are critically low.

Carb loading involves increasing carbohydrate intake for 1-3 days before a major event. Aim for 8-12g of carbs per kg of body weight daily, focusing on easily digestible sources. Reduce training volume during this period to maximize glycogen storage. The calculator's 'Carb Loaded' option accounts for this increased storage capacity in its calculations.

For rides over 60 minutes, a mix of glucose and fructose in a 2:1 ratio allows for optimal absorption (up to 90g/hour). This is because these sugars use different intestinal transporters. Sports drinks, gels, chews, and easily digestible foods like bananas, rice cakes, or energy bars are all good options. Personal preference and gut comfort should guide your choices.