Conclusion

The results of this study suggest that menstrual cycle phase has minimal influence on resistance training performance. Although statistically significant differences in average peak mean velocity were observed for some menstrual cycle phases, the magnitude of these differences were of a trivial to small magnitude (~ 0.01–0.02 m·s⁻1), suggesting they are unlikely to be meaningful from a practical perspective. Motivation to train was a significant independent predicter of training performance, highlighting that it may play an important role in determining training outcomes. The effects of symptoms on training performance depended on the symptom domain and may be exercise specific. Importantly, this is the first study to extensively examine resistance training performance across the menstrual cycle, under real-world training conditions. Using best-practice methods to monitor the menstrual cycle alongside direct assessments of training performance, these findings indicate that, while menstrual cycle phase alone may not necessitate changes to training prescription, practitioners should consider athletes’ motivation and symptom profiles when planning resistance training.

Practical Considerations

Menstrual cycle phase appears to have minimal effect on resistance training performance under real-world conditions. Observed fluctuations in kinematic outputs were modest and fell within normal biological and technological error. In contrast, motivation to train demonstrated a meaningful independent association with performance, suggesting that psychological factors warrant consideration when monitoring athletes. Although symptom prevalence was highest in phase 1, symptom–performance relationships were exercise specific and varied by symptom domain. This emphasizes the importance of individualized symptom monitoring rather than phase-based modifications. Overall, these findings support the use of consistent resistance training prescription across the menstrual cycle, but practitioners may wish to consider athletes’ motivation and symptoms to optimize training performance.