“I don’t think I performed very well today,” Fu Yuanhaui, Chinese Olympic swimmer, said in her post-swim interview at the 2016 Rio Olympics. “It’s because my period came yesterday, so I felt particularly tired — but this isn’t an excuse, I still didn’t swim well enough.”
Female athletes in all arenas of sport might be able to relate to Yuanhaui’s sentiments. Many women believe their athletic performance is worse during their periods due to symptoms like cramps, headaches, or fatigue. In a study of elite female soccer players from the United Kingdom, researchers found that over half of the women surveyed reported poor appetite and sleep quality during menstruation [1]. They believed that this in turn contributed to their poorer performance during games. Nearly all of the players said that they had more fatigue and less physical power while they were on their periods, with two-thirds of them requiring over the counter pain medication to control their symptoms.
How might the menstrual cycle affect athletic performance?
But, there’s more to the story than just how being on your period affects athletic performance. Women experience an entire cycle of hormones every month that has both peaks and valleys. In this article, I’ll explore not just how menstruation can affect the athletic capabilities of female athletes, but how the entire cycle can influence performance. We’ll tackle some of the controversies surrounding “cycle syncing”, too.
As I’ve written previously, sports were largely not designed for the female body, as female athletes can face a wide-range of physical issues from years of high-intensity athletics. One of the more common side effects of athletics for women is the loss of their period, or amenorrhea. This is a problem because the menstrual cycle is a vital sign for women, meaning that it is a necessary marker of health. However, the cycle is not only impacted by intense activity, but it also works in reverse: the cycle can affect how the female body performs.
However, the cycle is not only impacted by intense activity, but it also works in reverse: the cycle can affect how the female body performs.
There are two primary phases and two main events of the menstrual cycle
The menstrual cycle contains two distinct phases (the follicular phase and the luteal phase) plus two distinct events (ovulation and menstruation). During the follicular phase, a hormone called follicular stimulating hormone (FSH) is released, causing the follicles in the ovary to mature and produce estrogen. The lining in the uterus thickens, the cervix begins to produce mucus, and there’s a peak in the luteinizing hormone (LH) all to prepare for the main event — ovulation. While FSH tells many follicles to mature, only one follicle (or two, in the case of fraternal twins!) fully matures and is released during ovulation.
After ovulation happens, the “leftovers” from the follicle form the corpus luteum, which produces progesterone. This kicks off the luteal phase, which is dominated by the hormone progesterone. Estrogen peaks again during the luteal phase, but to a lesser extent than in the follicular phase. After about 11-15 days, assuming the egg was not fertilized, the corpus luteum dissolves and the shedding of the endometrial lining, AKA menstruation, begins.
Cycle syncing may help you work with your body’s natural hormonal highs and lows
All of these changes can cause outward symptoms during each phase, from the hormonal peak of ovulation to the hormonal valley of the end of the luteal phase and beginning of menstruation. This is why some experts recommend working with your cycle by using cycle syncing, a practice that involves building your lifestyle around the phases of your cycle. From an athletic context, this can look like the following:
- Menstruation: rest on the first few days of your period, then introduce low-intensity activities like pilates or walking.
- Follicular phase: increase training, focusing on speed and strength with workouts like heavy lifting, boxing, or sprinting.
- Ovulation: focus on endurance training, such as long distance running and HIIT.
- Luteal phase: ensure you are giving yourself ample recovery time and increase mobility training, stretching, and Pilates.
What is the controversy around cycle syncing?
Cycle syncing has become quite trendy as of late, with many viral videos on social media exploring how women can design their life around their cycle, rather than feeling burdened by the changes their body goes through on a monthly basis. However, there are some who see this trend as “gimmicky”, claiming that it over-generalizes how the female body reacts to lifestyle inputs like diet and exercise. Many of these critics point to this recent systematic review of studies done on how the menstrual cycle affects elite athletic performance, noting that the study draws inconclusive results about whether or not the cycle affects performance [2].
Others contend that while there might be a small impact that the menstrual cycle has on female athletes and how they perform, building training around the cycle is unreliable and unhelpful. Some even say that cycle syncing is basically reducing women to their hormonal status, ignoring the individual needs and strengths of each female athlete.
What does the research actually say?
Are these critiques of cycle syncing valid? While it is true that women are individuals and should not be reduced to their hormonal cycles, there are some universal truths that come with how the menstrual cycle can impact athletic performance. Another narrative review from 2021 that analyzed a large number of studies on how the menstrual cycle impacts female athletes found that there were decreases in strength and aerobic performance in the late luteal phase (right before your period begins) [3]. This lines up with the perceived decrease in performance that athletes reported. The study concedes that more research needs to be done on this issue, as the data is fairly sparse.
Other research also points to this decrease in performance during the late luteal phase. This study on over 4,000 female participants showed that recovery times were higher when women were in the second half of their cycle [4]. This suggests that exercise was more physically demanding for them in the luteal phase rather than the follicular.
Another study involved two groups of women performing leg resistance training, mostly during the follicular phase or during the luteal phase (plus a control group) [5]. The group that exercised during their follicular phase saw significant increases in lean body mass and muscle gains, whereas the group that exercised during their luteal phase did not.
While the luteal phase correlates with decreased athletic performance, ovulation may boost it
An older study which focused on weight-lifting found that there is actually a significant increase in strength for women who are mid-cycle — AKA, when they’re ovulating [6]. This is also when testosterone peaks for women, and their hormones are at an all-cycle high. It makes sense that athletic performance would also get a boost [7].
Should female athletes practice cycle syncing?
While there are a number of studies pointing to differences in athletic performance and recovery at different points in the menstrual cycle, there’s not really any concrete evidence proving that a training routine built around cycle phases is better than a routine based on other factors. Other systematic reviews conclude by stating that exercise approaches should be built based on how an individual woman responds to her cycle, not necessarily a one-size-fits-all approach to fitness [8].
This is largely because the data is still very limited, especially on cycle-syncing training routines. Many of the studies named above didn’t use fertility symptoms (also known as biomarkers) in order to determine what phase a woman was in in her cycle. They merely estimated the phase based on days from the last period, a calendar method that may be inaccurate for any or multiple of a host of reasons. Here at Natural Womanhood, we know that there are more precise and evidence-based ways of determining where you are in your menstrual cycle, and it would be beneficial for all women to see more data on how exact hormonal changes across the cycle affect athletic performance.
The bottom line: Data is limited, but you have nothing to lose by trying cycle syncing
There is anecdotal evidence, however, that creating training routines around the cycle helps elite athletes, just ask the United States Women’s National soccer team! Their coach, Dawn Scott, tracked her players’ cycles to build a complex diet and exercise plan that eventually culminated in her team winning the 2019 Women’s World Cup. Although the scientific literature on cycle syncing for athletes is still in its infancy, using your cycle to optimize your workouts is worth a shot. There’s really no harm in trying it out, experts say. Plus, you’ll have the hidden benefit of becoming more knowledgeable about the natural rhythms of your body’s cycle — benefiting your health in more ways than just helping you lift heavier and run faster.
References:
[1] Phoebe Read, Ritan Mehta, Craig Rosenbloom, Elena Jobson & Katrine Okholm Kryger (2022) Elite female football players’ perception of the impact of their menstrual cycle stages on their football performance. A semi-structured interview-based study, Science and Medicine in Football, 6:5, 616-625, DOI: 10.1080/24733938.2021.2020330 [2] 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. [3] Carmichael MA, Thomson RL, Moran LJ, Wycherley TP. The Impact of Menstrual Cycle Phase on Athletes’ Performance: A Narrative Review. Int J Environ Res Public Health. 2021 Feb 9;18(4):1667. doi: 10.3390/ijerph18041667. PMID: 33572406; PMCID: PMC7916245. [4] Sims ST, Ware L, Capodilupo ERPatterns of endogenous and exogenous ovarian hormone modulation on recovery metrics across the menstrual cycleBMJ Open Sport & Exercise Medicine 2021;7:e001047. doi: 10.1136/bmjsem-2021-001047 [5] Wikström-Frisén, Lisbeth et al. “Effects on power, strength and lean body mass of menstrual/oral contraceptive cycle based resistance training.” The Journal of sports medicine and physical fitness vol. 57,1-2 (2017): 43-52. doi:10.23736/S0022-4707.16.05848-5 [6] Sarwar R, Niclos BB, Rutherford OM. Changes in muscle strength, relaxation rate and fatiguability during the human menstrual cycle. J Physiol. 1996 May 15;493 ( Pt 1)(Pt 1):267-72. doi: 10.1113/jphysiol.1996.sp021381. PMID: 8735711; PMCID: PMC1158967. [7] R Atukorala K.,Silva W.,Amarasiri L., D., Changes in serum testosterone during the menstrual cycle – an integrative systematic review of published literature, GREM Gynecological and Reproductive Endocrinology & Metabolism (2022); 01/2022:009-020 doi: 10.53260/grem.223012 [8] McNulty KL, Elliott-Sale KJ, Dolan E, Swinton PA, Ansdell P, Goodall S, Thomas K, Hicks KM. The Effects of Menstrual Cycle Phase on Exercise Performance in Eumenorrheic Women: A Systematic Review and Meta-Analysis. Sports Med. 2020 Oct;50(10):1813-1827. doi: 10.1007/s40279-020-01319-3. PMID: 32661839; PMCID: PMC7497427.Additional Reading:
Sports and the female body: A response to TIME magazine, Part I
How can sports respect the female body?: A response to TIME magazine, Part II
