Influence of Oral Contraceptives on Selected Hormonal and Metabolic Responses to Prolonged Submaximal Exercise in Moderately Active Women

This investigation assessed the influence of oral contraceptives (OC) on growth hormone (GH) and prolactin (PRL) responses to and energy substrate utilization during prolonged submaximal treadmill exercise (90 min at 50% VO$\sb2$ max). Subjects consisted of moderately active women (18-30 yrs) in a low dose OC group (n = 10), a high dose OC group (n = 5) and a control group (n = 10). Relationships between selected hormonal and metabolic responses were examined also within OC and C groups. Blood samples, obtained via an indwelling venous catheter during rest (2 hrs), exercise (10 min intervals) and during recovery (15 min), were assayed for GH, PRL, 17B-estradiol, progesterone, glucose and hematocrit. Corresponding respiratory gas samples were collected and respiratory exchange ratios were computed to estimate relative and absolute amounts of carbohydrate (CHO) and fat utilized during exercise. Analysis of variance with repeated measures and multiple regression techniques were used to analyze the data. OC groups exhibited higher initial GH responses and lower PRL levels during exercise than the C group. Circulating PRL levels during exercise decreased from basal levels for all groups. Blood glucose levels, R values, and absolute amounts of CHO utilized were lower in OC groups compared to controls. GH and PRL responses showed few relationships with estrogen levels within OC and C groups. PRL levels were associated with CHO oxidation in the C group, whereas, GH responses in OC groups were associated with fat utilization. OC use was associated with enhanced GH responses, inhibited PRL responses, and lower CHO utilization during exercise.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Kinesiology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Bemben, Debra Ann

Contributors dc:contributor

• Boileau, Richard A.

• Biology, Animal Physiology
• Chemistry, Pharmaceutical

Identifier

(UMI)AAI8815322

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/71076