PurposeThe aim of the study was to investigate the effects of the menstrual cycle on exercise performance and cardiovascular responses in female long‐distance runners.MethodsFifteen well‐trained female long‐distance runners aged 19.4±1.1 years were monitored for basal body temperature (BBT), systolic and diastolic blood pressure (SBP, DBP) and heart rate (HR) every morning for 2 months. They also recorded their menstrual periods, and ratings of perceived exertion (RPE) as exercise performance during the menstrual phase, the follicular phase, and the luteal phase.ResultSeven runners had normal menstrual cycle (NMC). Eight runners had abnormal menstrual cycle (AMC), including polymenorrhea (n = 2), oligomenorrhea (n = 3) and amenorrhea (n = 3). SBP, DBP, and RPE were significantly higher in the menstrual phase than in the follicular phase in runners with NMC, whereas SBP and DBP did not change significantly during the menstrual cycle in those with AMC. SBP and DBP tended to be higher in the luteal phase than in the follicular phase in runners with NMC. HR did not change significantly during the menstrual cycle in either group.ConclusionA large number of female long‐distance runners appear to have menstrual disturbances, and increased SBP and DBP in the menstrual phase may negatively influence exercise performance.
BackgroundEpidemiological studies have suggested that low or high birth weight is a risk factor for hypertension in later life. Generally, blood pressure is regulated by several factors, including the number of nephrons, hypothalamic pituitary adrenal function, and the autonomic nervous system (ANS). However, the mechanism by which low or high birth weight leads to hypertension has barely been elucidated. To address this lack of research, we studied the relationship between birth weight and ANS.PurposeThe aim of this study was to investigate the effect of birth weight on heart rate variability (HRV) and cardiovascular responses.MethodsIn nonsmoking, healthy volunteers aged 20 to 30 years, we measured ECG and blood pressure (BP) in the right arm by autonomic sphygmomanometer after stabilization for 5 min throughout the experiment. We allocated participants to a low‐birth‐weight group, normal‐birth‐weight group, and high‐birth‐weight group.ResultBirth weight was inversely correlated with systolic BP and the ratio of low‐frequency to high‐frequency (LF/HF) power, an index of sympathetic nerve activity. There was a positive relationship between systolic BP and LF/HF.ConclusionLow birth weight probably has an influence on autonomic nervous system regulation.
The aim of this study was to investigate the effect of blood volume reduction (300 – 400 mL) on circulation and Heart Rate Variability (HRV), by using autologous blood donation as a model of blood volume change. In 33 adult subjects (56.3 ± 15.9yrs) with no circulatory, respiratory, or neurologic disease, we measured Blood Pressure (BP) and electrocardiographic parameters during autologous blood donation. We divided the subjects into 3 groups according to age (10–30 yrs, 40–50 yrs, and 60–80 yrs) and into 2 groups according to blood donation experience. In all age groups, the Low‐Frequency power/High‐Frequency power ratio (LF/HF) increased, and the HF power decreased during autologous blood donation. Additionally, during autologous blood donation, the 60–80 yrs age group exhibited the highest variation in HRV. In non‐experienced group, LF/HF decreased after autologous blood donation. Further, 1 subject developed Vaso‐Vagal Reaction (VVR). LF/HF was markedly higher in this subject than in the other subjects before autologous blood donation. After autologous blood donation, the decrease in LF/HF in the subject with VVR was similar that of subjects in the non‐experienced group. In the subject with VVR, BP decreased significantly, and the Heart Rate (HR) did not increase after autologous blood donation. In contrast, in the other subjects, BP decreased mildly and HR increased after autologous blood donation.
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