Menstrual cycle hormones and oral contraceptives: a multimethod systems physiology-based review of their impact on key aspects of female physiology.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of physiological outcomes across menstrual cycle phases and oral contraceptive use
PubMed 37823207 · doi:10.1152/japplphysiol.00346.2023
What was done
The authors conducted a multimethod systems physiology review, including a systematic review and meta-analysis examining substrate oxidation (carbohydrate and fat utilization) at rest and during acute aerobic exercise across menstrual cycle phases (follicular vs. luteal). They also reviewed evidence on the effects of menstrual cycle phases and oral contraceptive phases (active vs. placebo) on exercise performance, vascular function, and resistance exercise-induced muscle hypertrophy.
What was found
The abstract reports no numerical values, sample sizes, or effect sizes. Meta-analytic findings showed no difference between menstrual cycle phases in relative carbohydrate and fat oxidation at rest or during acute aerobic exercise. Across the broader review, differences between cycle phases and oral contraceptive phases were not associated with marked differences in exercise performance, vascular function, or muscle hypertrophy.
Why it matters
This paper synthesizes human physiological evidence to challenge assumptions that normal menstrual cycle fluctuations or oral contraceptive use substantially dictate metabolic responses, athletic performance, or adaptations to exercise training.
Limits
The abstract reports no numerical metrics, effect sizes, or study/participant counts. The authors emphasize that existing literature in female physiology often lacks rigorous methodological control and that data on variations in oral contraceptive formulation and androgenicity remain scarce.