Effects of the menstrual cycle on oxidative stress and antioxidant response to high-intensity intermittent exercise until exhaustion in healthy women.

Background: This study aimed to investigate the effects of the menstrual cycle on the oxidative stress and antioxidant response during high-intensity intermittent exercise until exhaustion in healthy women who habitually exercised.

Methods: Ten women with normal menstrual cycle completed 2 menstrual cycle phases, including the early follicular phase (FP) and the midluteal phase (LP). High-intensity exercise until exhaustion was performed on each test day. Blood samples were collected before the exercise (Pre), immediately after the exercise (Post0), and 60 minutes after the exercise (Post60). The levels of estradiol; progesterone; oxidative stress, which was measured as diacron reactive oxygen metabolites (d-ROMs); and antioxidant capacity, which was measured as the biological antioxidant potential (BAP), were assessed.

Results: The levels of serum estradiol and progesterone at Pre were significantly higher in the LP than in the FP (P<0.01). There were no significant differences in the d-ROMs, BAP, and BAP/d-ROMs between the FP and the LP at Pre, Post0, and Post60. Compared with the FP, the LP had significantly lower d-ROMs change rate from Pre at Post0 and Post60 (P<0.05). Moreover, the BAP/d-ROMs change rate from Pre showed a significantly higher trend in the LP than in the FP at Post0 and Post60 (P=0.06).

Conclusions: In women with regular menstrual cycle, oxidative stress during exercise and recovery may be eliminated during the LP, when the estradiol and progesterone levels are higher, compared with those during the FP.