| Objective: To evaluate the effects of aerobic exercise on cardiorespiratory fitness and endothelial function in middle aged women and whether these effects are related to the estrogen levels. Methods: In this test, a total of 45 healthy women aged 45-55 years were divided into exercise group (n=31, including 15 postmenopausal women) and control group (20 subjects). The exercise group conducted a 12-weeks aerobic exercise, while the control group had no exercise intervention. Each subject had taken cardiopulmonary exercise testing before and after 12 week with PVO2 reflecting the cardiorespiratory fitness. Plasma ADMA and NOS levels were measured to estimate endothelial function, and changes in plasma estrogen levels were also detected. Results: After 12 weeks, PVO2 and plasma NOS levels were increased, and plasma ADMA levels were decreased in exercise group as compared with the control group (P<0.05). However, there were no significant differences between premenopausal and postmenopausal women (P>0.05). Pearson correlation analysis showed the degrees of improvement in PVO2 was positively correlated with NOS (r=0.339, P=0.023), and negatively with ADMA (r=0.333, P=0.025). Both PVO2 and NOS had no correlation to baseline estrogen levels. Conclusion: The aerobic exercise training can significantly improve cardiorespiratory fitness in healthy middle-aged women and improve endothelial function as well. The increases in the cardiorespiratory fitness may be related to the improvement of endothelial function. The improvement of endothelial function is not dependent on the basic estrogen level, suggesting that premenopausal and postmenopausal women get the same benefit from exercise. |
