The diurnal patterns of cortisol and dehydroepiandrosterone in relation to intense aerobic exercise in recreationally trained soccer players.
Level 3 - non-randomized controlled study
Small repeated-measures crossover physiological study with unstated randomization.
PubMed 22734443 · doi:10.3109/10253890.2012.707259
What was done
Nine recreationally trained soccer players completed three separate trial days: rest (no exercise), morning exercise (10:00-11:30 h), and afternoon exercise (14:00-15:30 h), with 90 min of intense aerobic exercise. Saliva samples were collected at awakening, 30 min after awakening, and every 2 h from 08:00 to 22:00 h to evaluate waking diurnal cortisol and dehydroepiandrosterone (DHEA) cycles.
What was found
A waking secretory burst occurred for cortisol (p < 0.01) but not for DHEA. Diurnal decline was preserved across waking hours for both steroids on all days. Salivary cortisol significantly increased post-exercise at 12:00 h on the morning-exercise day (p < 0.05) and at 16:00 h on the afternoon-exercise day (p < 0.01) compared with other trials. No acute DHEA response occurred. Absolute hormone concentrations and effect sizes were not reported in the abstract.
Why it matters
The findings demonstrate that an acute bout of intense aerobic exercise triggers a transient cortisol spike without altering the overall waking circadian profile of salivary cortisol or DHEA.
Limits
The sample size is very small (n = 9) and limited to recreationally trained soccer players, preventing broad generalization. The abstract does not report numerical values, confidence intervals, or whether trial order was randomized.
Cited by
- contradicts After exercise, cortisol levels for the remainder of the day drop below baseline, heart rate variability improves, and blood pressure decreases.