What to watch with Cortisol and Sport?

Cortisol is a key stress hormone that rises during exercise to mobilize energy. However, chronic overtraining or stress can lead to persistently elevated cortisol, impairing recovery, immune function, and even promoting muscle breakdown. Watch for signs like persistent fatigue, poor sleep, frequent illness, or plateauing performance – these may indicate cortisol dysregulation. Certain genetic variants (e.g., in NR3C1, FKBP5, CRHR1) affect cortisol sensitivity, but they are rarely included in consumer DNA tests. MyBody-X tests do not cover specific cortisol markers. For clinical assessment, salivary or serum cortisol day profiles are more informative. Evidence: strong for acute exercise response, moderate for genetic prediction in consumer settings. Sources: none from provided context.