EFFECT OF REGULAR AEROBIC EXERCISE AND MENSTRUAL CYCLE ON CAROTID ARTERIAL STIFFNESS IN YOUNG FEMALE / 体力科学

Increased carotid arterial stiffness is associated with a risk factor of congestive heart failure. Thus factors that affect carotid arterial stiffness are of both physiological and clinical interest. The purpose of the present study was to examine the effects of regular aerobic exercise and menstrual cycle on carotid arterial stiffness in young female. The carotid β-stiffness index, an index of carotid arterial stiffness, was assessed in eight young female athletes (20.5 ± 0.4 years) and ten young female control subjects (21.3 ± 0.7 years). The carotid β-stiffness index was determined using ultrasound images of the common carotid artery with simultaneous recording of carotid arterial blood pressure by applanation tonometry. There was no difference in carotid β-stiffness index between the control and the athlete group both at the early follicular and the pre-ovulation phase of the menstrual cycle. On the other hand, the carotid β-stiffness index decreased from the early follicular phase to the pre-ovulation phase both in the control and the athlete group. These results suggest that carotid arterial stiffness in young females is not affected by regular aerobic exercise, but changes with the menstrual cycle, irrespective of exercise status.

CHANGES IN BRACHIAL AND FEMORAL ARTERY VASCULAR CONDUCTANCE IN NON-EXERCISING LIMBS DURING HANDGRIP EXERCISE / 体力科学

The purpose of this study was to determine the difference in vascular conductance changes in brachial and femoral artery (BVC, FVC) of non-exercising limbs during handgrip exercise at different intensities. Six subjects performed rhythmic handgrip exercise, which consisted of 2-second contraction and 2-second relaxation at the intensities of 15%, 30%, and 45% of maximal voluntary contraction (MVC). Brachial and femoral artery blood flow (Doppler ultrasound method) of non-exercising limbs, blood pressure, and heart rate were measured. The BVC during exercise at lower intensities (15% and 30%MVC) and FVC during exercise at any of three intensities did not change significantly. However, BVC significantly decreased at 45%MVC when the exercise was continued to longer than 60% of maximal endurance time (P<0.05). These results suggest that FVC of the non-exercising limb dose not change during handgrip exercise at the intensity lower than 45%MVC, but BVC of the non-exercising limb change during handgrip exercise depending on the exercise intensity and duration.