Runtrition

Plan your race nutrition with science-backed precision. Runtrition simulates glycogen depletion and tells you exactly when and what to eat during marathons, half marathons, ultras, and long training runs — so you never bonk. SMART NUTRITION PLANNING Enter your race distance, target pace, and body weight. Runtrition calculates your carb burn rate and creates a personalized fueling schedule with precise timing for every gel, chew, or drink. GLYCOGEN DEPLETION ENGINE See exactly when your body will run out of fuel. The app models glycogen stores based on your weight and shows a minute-by-minute simulation of energy depletion — and how each fuel stop keeps you going. TRAINING & GUT PREPARATION • Training Mode — practice nutrition during long runs with real-time tracking • Gut Training Plan — progressive program to build stomach tolerance over weeks • Rate gut comfort and get personalized recommendations RACE DAY FEATURES • Live Activity with lock screen fuel countdown and Dynamic Island • Apple Watch companion with haptic fuel and hydration reminders • Pre-race meal planner with carb-loading guidance • Weather-adjusted hydration recommendations MULTI-DAY & ULTRA SUPPORT • Plan nutrition for stage races and multi-day events • Per-stage breakdown with recovery guidance between stages • 5K to 100-mile distance presets plus custom distances INSIGHTS & ANALYSIS • Race history charts showing trends across all logged races • GI issue tracking and analysis • Compare nutrition plans side by side MORE FEATURES • Custom fuel creation with full nutrition profiles • Caffeine tracking with optimal timing • Export plans as PDF to share with your crew • Siri Shortcuts — ask "What's my next gel?" hands-free • iCloud sync across all your devices • Apple Health integration for weight sync FREE & PRO The core planner is completely free. Upgrade to Pro to unlock custom fuels, plan comparison, race logging, and advanced features. Whether you're running your first half marathon or your tenth ultra, Runtrition ensures your nutrition plan is as prepared as your training.