Kennedy Beursken | 2025 I.S. Symposium

Name: Kennedy Beursken
Title: Rat Races: A pilot study investigating the affects of ethinyl estradiol and levonorgestrel on aerobic endurance in female Spague-dawley rats
Major: Biology
Minor: Anthropology
Advisor: Sharon Lynn

According to the CDC, in 2018, approximately 22% of women between the ages of 15-49 used hormonal birth control. Many women use hormonal birth control, but the effects of birth control on certain aspects of life, like exercise and endurance, are understudied and require more research. This study investigates how ethinyl estradiol and levonorgestrel both synthetic hormones found in hormonal birth control affect aerobic endurance in female rats. The rats were split into four treatment groups: ethinyl estradiol (n=9), levonorgestrel (n=9), ethinyl estradiol and levonorgestrel (n=10), and control (injection without hormones) (n=9). The rats were aerobically trained and had their endurance tested through a series of treadmill and swim tests. I found that the group that was administered only levonorgestrel gained significantly more weight than the other groups following treatment. There were no significant differences time spent swimming among the groups during the weight-loaded forced swim test. There was not enough data to analyze the treadmill endurance tests. I concluded that ethinyl estradiol and levonorgestrel may have no effect on endurance. However, additional work is necessary, as there are limitations to this pilot study. Using information from this pilot study, a new experiment can be designed to produce meaningful results.

Posted in Symposium 2025 on May 1, 2025.