Sports science research has long been undertaken with male participants and findings generalised to females. However, we know there are significant differences between the sexes. Females have unique and varying hormone profiles which influence their physiology. The cyclic hormone changes during the menstrual cycle can affect many physical and psychological attributes and may influence sports performance.
Overview of the menstrual cycle
The menstrual cycle varies in length from 21-35 days, with the average typically 28 days. The menstrual cycle is characterised by 2 main phases: the follicular phase and luteal phase; and 2 main hormones: oestrogen and progesterone.
The early follicular phase, starting on day 1 of the cycle, is characterised by low oestrogen and progesterone and is when the menstrual bleed/period occurs. In the late follicular phase, oestrogen peaks near the time of ovulation, which is typically around halfway through the cycle (i.e., day 14).
The early luteal phase sees a drop in oestrogen after ovulation, whilst progesterone continues to rise. Oestrogen increases again in the mid-luteal phase, alongside a peak in progesterone. The late luteal phase sees a drop in both oestrogen and progesterone ahead of the cycle repeating.
The effects of oestrogen and progesterone
Studies have shown that oestrogen has a positive effect of exercise performance. Oestrogen has been found to have beneficial impact on muscle strength in females, increases muscle glycogen/carbohydrate storage, spares glycogen stores (delaying fatigue) and increases fat utilisation. (1,2) Oestrogen is also shown to have antioxidant properties which might protect against muscle damage caused by exercise. On the other hand, progesterone is thought to have the opposite effect of oestrogen. (3) Therefore, it is plausible that when oestrogen rises during the late follicular and the mid-luteal phase of the menstrual cycle, this might confer muscular performance benefits (with the greatest benefits in the late follicular phase when progesterone is low), and performance reduced during the early follicular phase when oestrogen is at its lowest.
Does the menstrual cycle impact exercise performance?
A 2020 systematic review and meta-analysis (a review which pools together all relevant existing studies) concluded that exercise performance might be slightly reduced during the early follicular phase of the menstrual cycle and performance consistent across all other phases. (4) However, it is difficult to form solid conclusions as this evidence is based on a large number of poor quality studies, with large variation between studies.
Another systematic review found that the menstrual cycle does not impact the rate of perceived exertion (RPE) during aerobic exercise, whist another found inconclusive effects on performance parameters among elite athletes. (5,6) Therefore, generalised guidelines on the effects of the menstrual cycle on performance cannot be formed and a personalised approach should be taken based on individual's responses to performance across their cycle.
What's the effect of oral contraceptives?
Oral contraceptives (OC) work to prevent ovulation, reducing the amount of natural oestrogen and progesterone and provide artificial oestrogen and progestin. Amongst females using OCs, studies have found exercise performance to be consistent across the cycle (no difference in performance between the consumption and withdrawal phases of typical oral contraceptives), however, those using OCs have slightly poorer exercise performance compared to naturally menstruating females not taking OCs. (7) However, as the effects are very small and variable across studies, there is no general guidance on OC use compared with non-use for exercise performance and an individualised approach is also recommended.
Summary
Research suggests that exercise perfomance may be slightly reduced during the early follicular phase of the menstrual cycle when oestogren is low and performance consistent across all other phases. However, we cannot yet make generalised recommendations - it is best that females track their own cycles to monitor exercise performance effects.
References
Lowe DA, Baltgalvis KA, Greising SM. Mechanisms behind estrogens’ beneficial effect on muscle strength in females. Exerc Sport Sci Rev. 2010;38(2):61–7.
Isacco L, Boisseau N. Sex hormones and substrate metabolism during endurance exercise. In: Hackney AC, editor. Sex hormones, exercise and women: scientific and clinical aspects. London: Springer; 2017. p. 35–58.
Frankovich RJ, Lebrun CM. Menstrual cycle, contraception, and performance. Clin Sports Med. 2000;19(2):251–71.
McNulty, K.L., Elliott-Sale, K.J., Dolan, E. et al. The Effects of Menstrual Cycle Phase on Exercise Performance in Eumenorrheic Women: A Systematic Review and Meta-Analysis.Sports Med 50, 1813–1827 (2020).
Prado RCR, Hackney AC, Silveira R, Kilpatrick MW, Takito MY, Asano RY. Effect of Menstrual Cycle Phase on Perceived Exertion During Aerobic Exercise in Eumenorrheic Women: A Systematic Review and Meta-analysis. J Womens Pelvic Health Phys Ther. 2024 Apr-Jun;48(2):91-102. Epub 2023 Sep 22. PMID: 38659609; PMCID: PMC11042688.
Meignié A, Duclos M, Carling C, Orhant E, Provost P, Toussaint JF, Antero J. The Effects of Menstrual Cycle Phase on Elite Athlete Performance: A Critical and Systematic Review. Front Physiol. 2021 May 19;12:654585. doi: 10.3389/fphys.2021.654585. PMID: 34093223; PMCID: PMC8170151.
Elliott-Sale KJ, McNulty KL, Ansdell P, Goodall S, Hicks KM, Thomas K, Swinton PA, Dolan E. The Effects of Oral Contraceptives on Exercise Performance in Women: A Systematic Review and Meta-analysis. Sports Med. 2020 Oct;50(10):1785-1812.
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