Under-fueling and Relative Energy Deficiency in Sport: Why Your Hemoglobin A1c Might Be High, Even If You’re an Endurance Athlete

Even the healthiest-looking endurance athletes can show lab results that tell a different story. Underfueling and low energy availability (REDs) can quietly raise cholesterol, disrupt hormones, and alter blood glucose and raise hemoglobin A1c — even in athletes who train hard and eat well. Learn how to recognize the signs of REDs, what your labs might be telling you, and how smarter fueling can protect long-term performance and health.