Episode 25 - Carb Loading: Don’t Start Empty

In this episode, we cover why carb loading is not about eating a huge bowl of pasta the night before a race, but about arriving at the start line with full fuel stores. For trail and ultra runners, glycogen is the body’s fast-access fuel, and starting underfuelled can make the later stages of a race much harder.

The key message is simple: carb loading should be planned, practised, and spread across the final 24–48 hours before race day. A good target for long endurance events is often around 8–12 grams of carbohydrate per kilogram of body weight per day, depending on the runner, the race, and gut tolerance.

The episode also explains what runners often get wrong: relying on one big meal, eating too much fibre or fat, trying new foods, or worrying about small increases in body weight caused by glycogen and water storage.

The practical advice is to use familiar, easy-to-digest carbohydrate foods, reduce gut stress before race day, and rehearse the strategy before key long runs or lower-priority races.

Main takeaway: Carb loading fills the tank before the race; race fuelling keeps topping it up. You cannot fully compensate during the race for arriving underfuelled.

Key references:

1. Thomas, D. T., Erdman, K. A., & Burke, L. M. — “Nutrition and Athletic Performance.”

2. Burke, L. M., Hawley, J. A., Wong, S. H. S., & Jeukendrup, A. E. — “Carbohydrates for training and competition.”

3. Wallis, G. A. — “Dietary Carbohydrate and the Endurance Athlete: Contemporary Perspectives.”

4. Vitale, K., & Getzin, A. — “Nutrition and Supplement Update for the Endurance Athlete.”

5. Kerksick, C. M. et al. — “International Society of Sports Nutrition Position Stand: Nutrient Timing.”

6. Mata, F. et al. — “Carbohydrate Availability and Physical Performance.”

7. Naderi, A. et al. — “Carbohydrates and Endurance Exercise: A Narrative Review.”

8. Thomas / ACSM position statement — race-day fuelling section