The influence of two different menstrual cycle phases on the relationship between DNA oxidation and hydration status following exercise (705.5)

Abstract

The purpose of this study was to determine the relationship between urinary 8‐hydroxy‐2’‐deoxyguanosine (8‐OHdG) and urine specific gravity (USG) following two hours of cycling exercise over the follicular and luteal phases. Twelve recreationally active eumenorrheic women served as the subjects [age: 20.9±0.3 year; height: 160.1±5.6 cm; body weight: 54.7±5.8 kg; body mass index: 21.3±1.8 kg/m2; body fat: 21.9±3.1 %; peak oxygen uptake (VO2peak): 44.4±5.0 ml/kg/min (mean±SD)]. Before and after 2 hours of cycling exercise performed at 60%VO2peak, 8‐OHdG and USG were determined with high performance liquid chromatography and a handheld refractometer, respectively. All subjects performed the same exercise protocol during the follicular (F: 5~8 days after the onset of the menses) and luteal (L: 22~25 days after the onset of the menses) phase. In order to delay fatigue and prevent hypoglycemia and dehydration, carbohydrate‐electrolyte solution were consumed every twenty minutes (2 ml/kg body mass) during each exercise protocol. No menstrual cycle differences were observed in the relationship between urinary 8‐OHdG and USG following exercise, assessed with an ANCOVA. The findings of the present study indicate that the follicular and luteal phases appear to be similar in terms of the relationship between oxidative DNA damage and hydration status following exercise.Grant Funding Source: Supported partly by funds from the Grant‐in‐Aid for Scientific Research (C) in Japan (No.23500867)