Glycogen stores are limited. Even with the best three-day carb loading protocol, most athletes have ~150 minutes of glycogen stored in muscles (and liver) when pushing at marathon pace or 70-85% of VO2 Max.

Muscles fuel (primarily) on carbs

A combination of multi-transportable carbohydrates (Glucose and Fructose) mixed to a 1:08 ratio enhances the absorption and oxidation rates well beyond single carb options. Using both SGLT1 and GLUT5 transporters maximizes total amount of carbohydrates delivered leading to improved performance and reduced gastrointestinal distress.

FUEL EARLY. FUEL OFTEN.

The basic principles of a good fuel plan. Wait to long and you will burn through your energy stores before the finish line. Take too much at one time and risk gas, reflux, stitch pain, vomit and diarrhea.