Three-step method for menstrual and oral contraceptive cycle verification

Area of Science:

• Exercise Science
• Sports Medicine
• Reproductive Endocrinology

Background:

• Ovarian hormone fluctuations can impact exercise performance, but their status is often unverified in research.
• Lack of standardized methods for tracking ovarian hormones limits the reliability of exercise science and sports medicine studies involving female participants.

Purpose of the Study:

• To evaluate a three-step method for verifying the mid-luteal (high hormone) phase in women using oral contraceptives or natural cycles.
• To identify demographic and hormonal factors associated with unsuccessful classification of the high hormone phase.

Main Methods:

• A cross-sectional study involving 54 recreationally-active women (oral contraceptive users and those with natural cycles).
• Utilized a three-step process: menstrual cycle mapping, urinary ovulation prediction, and serum/plasma hormone analysis.
• Verification of ovarian hormone concentrations was performed 6-12 days post-ovulation prediction.

Main Results:

• The three-step method successfully verified the mid-luteal phase in 100% of oral contraceptive users and 70% of naturally-menstruating women.
• Overall method success was 89% after excluding participants with luteal phase deficiency (30% of natural cycle group).
• Lower age, body fat percentage, and longer menstrual cycle length were significantly associated with luteal phase deficiency.

Conclusions:

• The described step-wise method is effective for verifying ovarian hormone status in physically active women.
• Incorporating age, body fat, and cycle length aids in identifying luteal phase deficiency.
• Findings support the development of stricter exclusion criteria for female participants in research to minimize hormonal variability in sports and exercise science.