CortisolStress hormone

Cortisol is a hormone released by the adrenal glands that helps mobilise energy, regulate metabolism and manage the body's response to stress. It naturally follows a daily rhythm, peaking in the morning and falling at night.

It matters because cortisol is often demonised, but it isn't 'bad' — it's essential, and rises normally with exercise. The concern is chronically elevated cortisol from persistent stress, poor sleep or excessive training, which can impair recovery, sleep and body composition.

In practice, the useful levers are managing overall stress load, sleeping well, and not endlessly overreaching in training — rather than chasing supplements that claim to 'lower cortisol'.