Effect Of Exercise Habits On Oxidative Stress During Menstrual Cycle

Abstract

It is known that the risk of oxidative stress differs between female athletes and non- athletes. However, the effect of exercise habits and oxidative stress in young women has not been fully investigated. PURPOSE: To investigate the effect of exercise habits on oxidative stress during the menstrual cycle. METHODS: Seven healthy women who have exercise habits (EX) and nine women who do not have exercise habits (NE) provided blood samples and data of physical activity during the menstrual phase (MP), follicular phase (FP), early luteal phase (EL) and late luteal phase (LL). All participants have a regular menstrual cycle and have never taken oral contraceptives. We measured plasma reactive oxygen metabolites (d-ROMs) and biological antioxidant potential (BAP). Oxidative stress index was calculated by d-ROMs/BAP. RESULTS: The EX tended to have higher d-ROMs levels than the NE (EX MP: 326 ± 43, EX FP: 335 ± 47, EX EL: 311 ± 26 EX LL: 303 ± 28, NE MP: 319 ± 56, NE FP: 309 ± 38, NE EL: 292 ± 36, NE LL: 284 ± 33 U.CARR, NS). The d-ROMs and BAP levels were unaffected by the menstrual cycle. Oxidative stress index below 7.33 are classified as oxidized type, and those above 7.33 are classified as antioxidant type. The EX tended to be oxidized type, while the NE tended to be antioxidant type (EX MP: 7.53 ± 1.07, EX FP: 7.06 ± 1.04, EX EL: 7.59 ± 0.81, EX LL: 7.92 ± 0.98, NE MP: 7.60 ± 1.26, NE FP: 7.90 ± 1.42, NE EL: 8.39 ± 1.29, NE LL: 8.39 ± 1.22, NS). Negative correlation was found between physical activity and antioxidant power during the FP (r = -0.57, p = 0.03). CONCLUSIONS: Higher oxidative stress was found in women with exercise habits. The risk of oxidative stress with or without exercise habits was unaffected by the menstrual cycle. These findings indicate that women with high physical activity may be at increased risk of oxidative stress.