RUN LONG, RUN HEALTHY — SEPTEMBER 4, 2025

Can You Cut Carbs in Your Pre-Race Meal And Still Run Fast?

A new study tests the hypothesis that the type of fuel we burn during exercise may be less important for performance than we thought

“What should I eat before my race?”

It’s one of the most common questions among runners, and also one of the biggest sources of pre-race anxiety. We tend to obsess over getting everything right (sometimes down to the calorie). Despite everything we’ve learned about sports nutrition, we still don’t have a clear picture of the optimal pre-race meal.

It’s generally accepted among athletes that carbohydrates should make up most of the diet in the hours before a race (and, in many cases, throughout training). The rationale is straightforward — carbs support blood glucose levels and maximize glycogen availability, which becomes especially important when racing or exercising for several hours. In fact, numerous studies have shown that consuming carbohydrates before exercise can significantly improve performance.

More recently, though, researchers have asked whether a lower-carbohydrate, higher-fat diet might also be compatible with endurance performance. It’s a…