While dietary amino acids and resistance exercise are recognised regulators of muscle protein turnover, skeletal muscle is also exposed to cyclical fluctuations in ovarian hormones across the menstrual cycle. Whether these hormonal fluctuations meaningfully influence skeletal muscle anabolic regulation remains unclear, yet menstrual cycle phase-based exercise recommendations have emerged.

This presentation will synthesise current evidence alongside findings from two complementary stable isotope tracer studies conducted in healthy, eumenorrheic females using gold-standard cycle phase verification under tightly controlled experimental conditions. The implications of these findings for menstrual cycle phase-based training recommendations, inclusion of females, and study design considerations in skeletal muscle physiology research will be discussed.