Cardiovascular disease remains the number one cause of death for women. Arterial stiffness has been used as a predictor of future heart disease. Arterial stiffness decreases with aerobic training in older men and women. The purpose of this study was to test whether a 14-week aerobic (stationary cycling) training program improves arterial stiffness in nine healthy pre-menopausal sedentary women. Measures of body composition (DXA), cardiorespiratory fitness (VO2peak) and carotid arterial stiffness, defined as beta stiffness index, compliance, and distensibility were measured before and after the training. Fitness improved by 9.4% (P=0.016), with no significant changes in body composition. Arterial stiffness did not change with training, pre 6.453.5 (U) to post 6.361.75 (U) (P=0.46). In conclusion, aerobic training does not appear to improve arterial stiffness in younger women whose arteries did not show increased stiffness pre-treatment.