Of the three nutrients that provide energy, carbohydrate and fat are the main ones that fuel endurance exercise. As exercise intensity increases, the body's fuel source crosses over from predominantly fat to a higher percentage of carbohydrate. The easier you ride, the more fat you will burn; but, when things start to get faster or more punchy/technical, the more carbohydrate you need to sustain the effort. Of course, with proper training and nutrition, physiological adaptations over time allow us to improve fat oxidation at a higher percentage of our maximal aerobic capacity. Carbohydrate, however, still remains an essential energy source for endurance performance and recovery from mountain bike training and racing.
Stored glycogen (carbohydrate stored in the liver and muscle) and carbohydrate supplements such as sports drinks, gels, and gummies are the primary source for carbohydrate fuel that allows you to keep up the effort and pace during training and racing. Here's five tips that will help you to properly fuel your ride:
1) For < 60 minutes of easy riding (active recovery or very easy endurance riding), 0-30 grams of carbohydrate per hour is sufficient. Example: Water, nuun electrolyte supplement in water, 1 gel, or 1 serving of gummies (~100-120 calories) per hour.
2) For 60-120 minutes of easy endurance riding, 30 grams of carbohydrate per hour is usually sufficient. This could be achieved with a mix of sports drinks, gels with water or nuun, and/or gummies plus water or nuun. Typically, mountain biking will include some intensity due to the nature of the terrain and obstacles so depending on the ride length and difficulty, it would be OK to take in slightly more than 30 g carbohydrate per hour.
3) For rides longer than 2 hours, take in up to 60 g carbohydrate per hour (240 calories per hour). This is best done using a sports drink such as SWORD with gels and/or gummies.
4) Before harder practice rides or races, eat a carbohydrate rich snack or meal before training. This should be something easy to digest such as: banana, toast, rice, waffle, or even sports drink or gummies. The closer to the training session or race, the more "simple" the carbohydrate should be. For example, if you have less than 30 minutes before riding or racing, use sports drinks, gels, and gummies.
5) To optimize stored muscle glycogen for the next training session or race, take in approximately 50-60 grams of carbohydrate with fluid immediately after a hard training session or race. A small amount of protein (10-15 grams) can also be added to the recovery drink or snack.
Namrita Kumar, Ph.D., RD
Head Cycling Coach