Myths vs facts: Cortisol and Sport

Cortisol is a vital hormone that rises during exercise to mobilize energy and modulate inflammation. A common myth is that cortisol is always harmful – in reality, acute spikes during training are normal and support adaptation. Another myth: cortisol directly causes belly fat. While chronic elevation from ongoing stress can promote fat storage, it's not a direct causal link. Facts: Cortisol follows a circadian rhythm; intense training can disrupt it. Overtraining and poor sleep chronically elevate cortisol, impairing recovery and immune function. Evidence comes from exercise physiology studies, but individual variability is high. Consumer cortisol tests (saliva, hair) have limitations – they provide snapshots, not diagnoses. For athletes, focusing on balanced training, nutrition, and recovery is more impactful than obsessing over cortisol numbers.