RED-S Explained: Why Underfueling Hurts Your Performance More Than You Think

Training harder but not getting faster? Dealing with recurring injuries? The problem might be your fuel. Before Thanksgiving, I'm sharing an episode from Your Diet Sucks about RED-S, the energy mismatch that's quietly destroying athletic performance and causing injury after injury. When you chronically undereat for your training load, your body can't adapt. You're doing the work, but not getting the gains. Studies show athletes with RED-S are 4.5x more likely to get bone injuries and miss significantly more training time. Signs You're Underfueling: Training harder but getting slower Stress fractures or injuries that won't heal Constantly exhausted despite rest days Lost period (or loss of morning erections in men) Frequent colds and illness You can't out-train a calorie deficit. Adequate fueling is how you honor your training. Going into the holidays: eat the food, recover hard, and come back stronger. In this episode: What RED-S is, how it shows up in male athletes (often overlooked), why it prevents adaptation, and how to fuel for actual performance gains, not just more miles. Listen before your holiday meals. Food is fuel. Recovery is where you get faster.