Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)



First Advisor

Arnold G. Nelson


During menopause, many women experience weight gain which is mostly in the form of abdominal and upper body fat deposition. This phenomenon has been recognized as an independent predictor of cardiovascular disease in females. Other disease processes, such as diabetes, hypertension and some cancers, specifically, breast and esophageal have been linked to obesity. Thus, the occurrence of increased body fat is placing the postmenopausal female in jeopardy of a potential life-threatening position. The connection between the lack of estrogen seen in menopause and weight gain remains unclear, but studies have shown that estrogen status may affect carbohydrate and fat metabolism. This study examined the metabolic responses at rest and during a low-to-moderate intensity cycle ergometer exercise session of thirty-two premenopausal females at different levels of estrogen status. Eleven subjects (Group M) were tested during day 1 thru 4 of their menses which represented low estrogen status; fourteen subjects (Group F) were tested during the follicular phase (day 8 thru 12) which represented high estrogen status; and 7 subjects (Group G) who were being treated with a GnRH agonist analogue (Depot Lupron) to suppress estrogen synthesis, were tested to represent the post-menopausal female. Estrogen status was confirmed by blood analysis for all subjects. Testing consisted of a 15-minute rest period and a 20 minute submaximal cycle ergometer test. The exercise protocol consisted of 2 minute staged increments of 10 watts, beginning at 0 watts, until the subject reached between 60 and 70% of her age-predicted maximum heart rate (220 minus age). Respiratory gases were analyzed using the Quinton QMC$\sp{\rm TM}$ metabolic cart in the breath-by-breath mode. Blood was drawn at the end of the rest session, at 10 minutes and 20 minutes of exercise. Results indicated that the pseudomenopausal model demonstrated non-significant differences in fuel substrate utilization. It is possible that the lack of estrogen is not an underlying factor of the weight gain seen in menopause, but further investigation is required.