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

Area of Science:

• Endocrinology
• Immunology
• Cancer Biology

Background:

• Psychological stress and elevated cortisol are linked to increased cancer incidence and mortality.
• Cortisol, released during stress, regulates immune activity via glucocorticoid receptors (GCRs).
• Chronic stress-induced cortisol may promote tumor progression and reduce cancer treatment efficacy.

Purpose of the Study:

• To investigate cortisol secretion dynamics following exercise.
• To determine the effects of exercise-induced cortisol on T cell effector functions.
• To compare acute versus chronic stress effects on T cells and cancer cells.

Main Methods:

• Measured circulating cortisol levels after 40-min high-intensity exercise versus a 5-min sprint.
• Assessed human CD3+ T cell proliferation, cytokine release, and killing activity after acute (4h) cortisol exposure.
• Evaluated T cell functions and cancer cell proliferation under chronic cortisol exposure.

Main Results:

• 40-min high-intensity exercise significantly increased cortisol; a 5-min sprint did not.
• Acute cortisol exposure did not impair T cell effector functions.
• Chronic cortisol exposure dampened T cell functions and induced cancer cell proliferation.

Conclusions:

• Acute exercise-associated cortisol has different effects than chronic stress cortisol on immune and cancer cells.
• Cortisol signaling modulation may enhance cancer immunotherapy efficacy.
• Exercise-induced cortisol may have beneficial roles in cancer management.