Prolonged exposure to the stress hormone cortisol reduces the ability of immune cells called tumor-specific T cells to destroy cancer cells in laboratory settings, and this reduction lasts even after the cortisol is gone. Short-term exposure to cortisol does not have this effect.

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Evidence from Studies

Supporting (1)

27

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Exercise Duration Modulates Cortisol Release and Chronic Cortisol Exposure Jeopardises T Cell Effector Functions

Randomized Controlled Trial

Human & In Vitro

2026 Jan

When cortisol stays high for a long time, it weakens the immune cells that fight cancer, even after the cortisol is gone. But short bursts of cortisol, like during a quick workout, don’t hurt these cells.

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Source Study

Exercise Duration Modulates Cortisol Release and Chronic Cortisol Exposure Jeopardises T Cell Effector Functions

Score: 27

DOI: 10.1111/imm.70028

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