Caffeine shifts fuel use towards fat during outdoor running ☕Real-world application for runners.Tom CoughlinSep 17, 2026∙ Paid3ShareCaffeine Shifts Substrate Utilization Toward Fat During Outdoor Running at Fatmax: A Randomized Field-Based Crossover StudyThanks for reading Performance Nutrition Digest! Subscribe for free to receive new posts and support my work.SubscribeStudy DetailsThis new study tested whether 3 mg/kg caffeine alters substrate use during 1 hour of outdoor running at Fatmax…Continue reading this post for free, courtesy of Tom Coughlin.Claim my free postOr purchase a paid subscription.PreviousNext