Citation

Redman LM, Weatherby RP. Med. Sci. Sports Exerc. 2004; 36(1): 130-136.

Affiliation

Exercise Physiology Laboratory, Department of Physiology, University of Adelaide, Adelaide, SA, Australia. redman@ohio.edu

Copyright

(Copyright © 2004, Lippincott Williams and Wilkins)

DOI

10.1249/01.MSS.0000106181.52102.99

PMID

14707778

Abstract

PURPOSE: The aim of the study was to use a low-dose oral contraceptive (OC) pill to generate consistent estrogen and progestogen concentrations and investigate the relationship between steroid hormone concentrations during the OC cycle and anaerobic performance. METHODS: Five female rowers taking a low-dose OC performed tests of anaerobic power (10-s all-out effort) and capacity (1000-m row) on the Concept IIC rowing ergometer at two time points in each of three OC cycles. These time points corresponded to high estrogen and high progestogen (pill day 16-18; TDH) and low estrogen and low progestogen (pill day 26-28; TDL). Blood samples were collected at rest and postexercise for the quantification of 17beta-estradiol (E2), progesterone (P4), glucose, triglyceride, and lactate concentrations. RESULTS: Endogenous E2 and P4 concentrations were not significantly different between testing days or OC cycles (P > 0.05). Peak power output was higher (P < 0.05) and 1000-m rowing ergometer time faster (P < 0.05) at TDL. Pre- and postexercise glucose concentrations were increased (P < 0.05) at TDL, whereas rest and postexercise plasma triglyceride concentrations were significantly (P < 0.05) lower during this time. CONCLUSIONS: This study found that alterations in anaerobic performance throughout the OC cycle occurred with improved performances corresponding to low estrogen and progestogen concentrations. The OC provided a consistent hormonal milieu reducing inter- and intra-individual variations in sex steroids and standardized all performance and metabolic variables across each OC cycle tested. Given that OC use has a high prevalence among female athletes and provides a controlled hormonal environment, it serves as a good model in which the acute effects of female sex steroids on exercise performance can be studied.

Language: en