Perceived Pain And Mood State Is Influenced By Fluctuations In Salivary Estradiol And Progesterone Levels

Our lab has evidence that exercise elicits an analgesic response both during and following exercise and this effect is more pronounced in females relative to males. Although we are unsure why we speculate that these differences are mediated hormonally. PURPOSE: To assess changes in minimal pain threshold, a marker of analgesia, and subjective mood state at different stages of the menstrual cycle and correlate these findings with salivary estradiol and progesterone levels. METHODS: Female subjects (n = 16; age = 21.1 ± 0.5) whom self-reported not currently using birth control performed 30 minutes of submaximal treadmill exercise and were studied at two different time points during their monthly menstrual cycle (follicular and luteal phases). Each subject exercised in a range between 120-150 bpm. Exercise analgesia was tested by way of a minimal pain threshold (MPT) using a pain-pressure algometer on the extensor carpi radialis. A Psychoactive Effects Questionnaire (PEQ) was used to assess subjective mood state both before and after each bout of exercise. Saliva was collected before each testing session and was frozen to be later assayed. Saliva samples were quantified with ELISA assays to determine estradiol and progesterone levels for each timepoint. A paired T-test was used to determine differences (pre vs. post-exercise) in our variables of interest (PEQ, and MPT) during the two points (follicular and ovulatory phases). Relationships were evaluated using a Pearson’s correlation coefficient. Data are shown as mean ± SEM. Significance was set to p < 0.05. RESULTS: At both time points (follicular and luteal), MPT and PEQ were increased following acute exercise (p < 0.01). However, MPT was increased to a greater extent (p < 0.05) during the luteal phase (Δ 57% ± 5.2) relative to the follicular phase (Δ 28% ± 9.21). Further, progesterone levels were significantly correlated with MPT (r = 0.7831; R2 = 0.811; p < 0.05) but not with PEQ. Lastly, there was a relationship between estradiol and PEQ (r = 0.79; R2 = 0.63; p < 0.05) and positive response were higher during follicular phase relative to the luteal phase (p < 0.05). CONCLUSION: Pain perception and mood state may change during the menstrual cycle due to hormonal fluctuations. Therefore, exercise enjoyment and adherence may differ based upon a female’s current hormonal status.