The Menstrual Cycle and Strength

In summary, the effects of the menstrual cycle on strength performance remain unclear.

The Menstrual Cycle (MC) is an important biological rhythm in which acute cyclic fluctuations of oestrogen and progesterone occur monthly (Elliott-Sale et al., 2021). The MC can be split into four phases: early follicular, late follicular, ovulatory, and mid-luteal (Elliott-Sale et al., 2021). The varying hormonal concentrations during each phase have potential to cause performance implications in female athletes (McNulty et al., 2020). However, the direction and magnitude of the effects on sporting performance are still not fully understood. This is partially linked to the underrepresentation of females in exercise science research (Costello et al., 2014). Additionally, the poor methodological standards of some female menstrual cycle research make it difficult to draw conclusive results (McNulty et al., 2020).

The effects of the MC on strength performance remains conflicting. Nevertheless, there is some evidence to suggest that muscle strength and power are not impacted by the monthly changes in hormonal levels (Arazi et al., 2019). This can be said for both eumenorrheic women and oral contraceptive users (Dasa et al., 2021). Regarding MC phase-based training, some studies reported favourable strength gain results for females training in the follicular phase (when oestrogen concentration is elevated) vs the luteal phase (Thompson et al., 2020). Unfortunately, the methods used to detect menstrual cycle phase were of low methodological standard (i.e., used calendar-based counting and/or basal body temperature measurements over blood hormone concentrations), thus making the interpretation of such results all the more difficult. 

In summary, the effects of the MC on strength performance have yet to be elucidated. Some studies suggest that the MC phase has little or no impact on strength. However, there is also some evidence to suggest that training during the late follicular phase (greater oestrogen levels) can lead to greater strength gains. To help overcome the heterogeneity and ambiguity of results, higher-quality female research is warranted.

Niamh Fogarty is a Year 4 student on the BSc in Athletic and Rehabilitation programme in the Department of Sport and Health Sciences.  Niamh completed an internship during Summer 2021 with Dr Ciaran O Cathain and PhD student Cherianne Taim. 

Reference:

Arazi, H., Nasiri, S. and Eghbali, E. (2019) ‘Is there a difference toward strength, muscular endurance, anaerobic power and hormonal changes between the three phase of the menstrual cycle of active girls?’, Apunts. Medicina de l’Esport, 54(202), pp. 65–72. doi:10.1016/j.apunts.2018.11.001.

Costello, J.T., Bieuzen, F. and Bleakley, C.M. (2014) ‘Where are all the female participants in Sports and Exercise Medicine research?’, European Journal of Sport Science, 14(8), pp. 847–851. doi:10.1080/17461391.2014.911354.

Dasa, M.S. et al. (2021) ‘The Female Menstrual Cycles Effect on Strength and Power Parameters in High-Level Female Team Athletes’, Frontiers in Physiology, 12, p. 600668. doi:10.3389/fphys.2021.600668.

Elliott-Sale, K. et al. (2021) ‘Methodological Considerations for Studies in Sport and Exercise Science with Women as Participants: A Working Guide for Standards of Practice for Research on Women’, Sports Medicine, 51, pp. 1–19. doi:10.1007/s40279-021-01435-8.

McNulty, K.L. et al. (2020) ‘The Effects of Menstrual Cycle Phase on Exercise Performance in Eumenorrheic Women: A Systematic Review and Meta-Analysis’, Sports Medicine (Auckland, N.z.), 50(10), pp. 1813–1827. doi:10.1007/s40279-020-01319-3.

Thompson, B. et al. (2020) ‘The Effect of the Menstrual Cycle and Oral Contraceptives on Acute Responses and Chronic Adaptations to Resistance Training: A Systematic Review of the Literature’, Sports Medicine (Auckland, N.Z.), 50(1), pp. 171–185. doi:10.1007/s40279-019-01219-1.