We have noticed a marked increase in the number of women following structured training programmes. Recently, many sports scientists and coaches have begun to question whether training interventions which have been shown to be effective in men, should be applied to women without further consideration. In fact, a recent systematic review and meta-analysis (1) showed that for a given training load, men and women exhibited significantly different improvements in VO2max. We acknowledge that VO2max is not the best predictor of endurance performance, but it is still interesting to note the differences between the sexes in their response to an identical training load.
It is logical to expect that men and women would respond differently to the same training stimulus; in fact, individuals of the same sex will most likely respond differently to the same training load. There are large differences in the physiology between men and women, so we should expect differences in their responses to endurance training. One such physiological difference is the presence of the menstrual cycle in women. The menstrual cycle is characterised by cyclical changes in the concentration of the female sex hormones: oestrogen and progesterone. Do these fluctuating hormone levels impact a women’s response to, and recovery from exercise training and, therefore, ultimately their performance?
A recently published pilot study investigated whether recovery from a standardised exercise session differed during the mid-follicular (~ 8 days after the onset of menses) and mid-luteal (~ 23 days after the onset of menses) phases of the menstrual cycle (2). The results showed that trained female endurance athletes exhibited an elevation in markers associated with muscle damage and inflammation during the mid-follicular phase compared to the mid-luteal phase following a standardised training session. The authors of the study acknowledge that it is only pilot data, but the results are certainly interesting and suggest that female endurance athletes may need a longer recovery period from harder sessions during the mid-follicular phase.
If recovery from exercise is influenced by the phase of the menstrual cycle, it stands to reason that exercise performance may also be impacted in some way. Do we currently have sufficient evidence to support practical guidelines for performance during the different phases of the menstrual cycle? The detailed answer to this question can be found in this excellent systematic review and meta-analysis that was published recently (3). The short answer is that there is currently insufficient evidence available to support structuring training around the menstrual cycle. The absence of any evidence-based guidelines at this point in time is mostly due to the relatively low-quality of the research available on this topic. There will most likely be a large increase in research studies that attempt to answer this question now that this review has highlighted the gaps in the literature, so stay tuned.
Female athletes and their coaches should adopt a personalised approach to their training during the different phases of the menstrual cycle. An athlete may notice that their recovery is slower during the early and mid-follicular phases (when sex hormone levels are low) compared to other phases, and their recovery strategies could then be periodised to ensure optimal adaptation. Subjective ratings of fatigue and under-performance in training or racing can be used to create a performance profile for an athlete during the different phases of the menstrual cycle.
REFERENCES
- Diaz-Canestro C, Montero D. Sex Dimorphism of VO2max Trainability: A Systematic Review and Meta-analysis. Sports Med. 2019;49(12):1949-56.
- Hackney AC, Kallman AL, Aggon E. Female sex hormones and the recovery from exercise: Menstrual cycle phase affects responses. Biomed Hum Kinet. 2019;11(1):87-9.
- McNulty KL, Elliott-Sale KJ, Dolan E, Swinton PA, Ansdell P, Goodall S, et al. The Effects of Menstrual Cycle Phase on Exercise Performance in Eumenorrheic Women: A Systematic Review and Meta-Analysis. Sports Med. 2020
