Carbs for Endurance: How Much Do You Actually Need?

In this episode of The Athletes Compass, Paul Warloski and Dr. Paul Laursen unpack the current high-carb fueling trend in elite endurance sport, sparked by reports of top marathoners consuming 100–120 grams of carbohydrate per hour. The conversation challenges the traditional idea that carb intake primarily boosts performance by sparing muscle glycogen, instead highlighting emerging research suggesting that even small amounts of carbohydrate may work mainly by protecting blood glucose and preventing hypoglycemia. They explore whether high-frequency carb dosing may act more like a brain signal or “performance unlock,” why everyday athletes should be cautious about copying elite fueling strategies, and why training fundamentals still matter far more than gels, shoes, or marginal gains.Key TakeawaysCarbohydrates do improve endurance performance compared with placebo, but the mechanism may not be simple “more fuel equals more speed.”Emerging research discussed in the episode suggests that preventing low blood sugar may be more important than sparing muscle glycogen.Very high carb intakes, such as 90–120g per hour, are being used by some elite marathoners, cyclists, and triathletes, but that does not automatically mean they are right for everyday athletes.High carb dosing may have a brain-mediated or mouth-rinse-like effect, potentially signaling that energy is available and allowing athletes to access another “gear.”More carbohydrate can sometimes increase glycogen use rather than spare it, which complicates the traditional fueling model.High doses of carbohydrate may increase the risk of gastrointestinal distress, especially when not practiced in training.For many age-group and masters athletes, a more moderate fueling approach may be safer and more practical.The hosts emphasize that training, aerobic development, preparation, and consistency matter far more than copying elite nutrition headlines.The role of advanced glycation end products in aging and metabolic diseases: bridging association and causality - PMCCarbohydrate ingestion eliminates hypoglycemia and improves endurance exercise performance in triathletes adapted to very low- and high-carbohydrate isocaloric diets - PubMedCarbohydrate Ingestion on Exercise Metabolism and Physical Performance - PubMedNonenzymatic browning in vivo: possible process for aging of long-lived proteins - PubMedLiver and muscle glycogen oxidation and performance with dose variation of glucose-fructose ingestion during prolonged (3 h) exercise - PubMedCarbohydrate dose influences liver and muscle glycogen oxidation and performance during prolonged exercise - PubMedThe effect of carbohydrate mouth rinse on 1-h cycle time trial performance - PubMedPaul Warloski - Simple Endurance Coaching