[This is a guest post by Beatriz Fernandes. Beatriz received her BS in Exercise Science, MS in Management and is currently participating in the Athletic Lab Internship Program. Beatriz has experience coaching at a variety of levels in the US and over in Europe and holds certifications with US Soccer.]

In my previous blog post, we examined how the menstrual cycle might contribute to women’s sports performance. As suggested by some experts and researchers, the menstrual cycle is what makes women’s physiology so unique, complex, and surely worth studying.

Unfortunately, despite the growing interest on the subject, there is not much research about the effects of menstrual cycle in sports performance. Only recently have sports scientists been investing their time and attention to something that is both common and commonly unspoken. Studies suggest that embarrassment and lack of education on the matter may explain why both athletes and coaches are uncomfortable sharing ideas. This is especially true between different genders. According to FitrWoman, 74% reported their menstrual cycle negatively affected their performance, 82% had never discussed their menstrual cycle with their coach, and 72% received no education regarding exercise and their menstrual cycle.

History mini-crash-course:

It was not until the late 70 s, when menstrual problems such as amenorrhea and late menarche were considered to go hand in hand with women exercising (P. Bale, 1970). The “Female Athlete Triad” was then a traditional justification for the combination of disordered eating, hormonal changes (that led into irregular periods), and low bone density. It was believed that women in sports would be at risk of disturbed menstrual function from the first minute of physical activity. Fast forward to 2014, the International Olympic Committee (IOC) came forth to consider the triad as a syndrome called Relative Energy Deficiency in Sport (RED-S), which is far more complex than just three factors working together; and not exclusive to women. RED-S is a condition caused by low energy availability, which impairs many aspects of physiological functions such as menstruation, musculoskeletal health, cardiovascular function and metabolic rate immunity, protein syntheses, gastrointestinal function, and even growth and development” (Sims, 2016; Pitchers & Elliot-Sale, 2019).

Menstrual dysfunction can be related to sports, but sports are not necessarily the cause. The dysfunction is simply the visible symptom of some other problem. Female athletes are often insufficiently or improperly fueled. This leads to insufficient available energy for basic physiological functions, let alone for sports. This energy deficit affects hormonal pathways and in women, the syndrome usually manifests in menstrual problems.

It is important to understand that all women have different bodies, schedules, experiences, and symptoms when it comes to the menstrual cycle and even the same body can have a different experience each cycle. Eumenorrheic women have a “traditionally healthy” 28 day cycle of which we will take a closer look.

Menstrual Cycle 101:

The typical menstrual cycle on eumenorrheic women can be split into two main phases with four distinct moments:
Follicular Phase – Menstruation (the bleed) and Egg maturation/ovulation;
Luteal Phase – Premenstrual phase (High Hormonal Phase) and Premenstrual period.
During the menstrual cycle, hormones fluctuate throughout an entire month; (every 28-35 days) on a constant cycle (9-10 times/year) and around 457 times in life until menopause, which is the cessation of menstruation (Pitchers & Elliot-Sale, 2019). It is also important to understand this hormonal dynamic:

Phase 1 (Follicular) – Menstruation (The Bleed)

The shedding of the endometrial lining and the beginning of the cycle, the bleed is usually what people consider “the period,” but notice that bleeding is simply a consequence of an intricate process within the female body, which is almost less than one fourth of the whole menstrual cycle process. This low hormone phase typically lasts between 2-7 days.

Phase 2 (Follicular) – Egg Maturation/Ovulation

The ovaries mature an egg to be released and prepare a “bed” in the uterus for it.
The pituitary gland in the hypothalamus releases two stimulating hormones (FSH and LH) that are responsible for the ovaries’ release of an egg ready to be fertilized. Still in the ovaries, FSH will then mature some follicles (“pod” in which eggs mature) in the ovaries causing the levels of estrogen to rise; the latter will be responsible for the “bed in the uterus” by thickening and maintaining its lining. Around the 12th-14th day of the cycle, the estrogen levels surge along with the LH, and ovulation of a matured egg occurs. This is the midpoint of the cycle.

Phase 3 (Luteal) – Premenstrual Period (High Hormonal Phase)

After the egg’s release, progesterone and estrogen will prepare the lining of uterus for an eventual egg implantation, in case it becomes fertilized. This is a high hormone phase that will last around 10 days before declining. This is approximately day 22-24, which is around five days before menstruation. The uterus is thick and all the body fluids are ready for pregnancy OR menstruation (the bleed).

Phase 4 (Luteal) – Premenstrual Phase

When the symptoms happen. In this pre-menstrual window, if no egg is implanted, the body realizes that there is no need for such arrangement and the hormone levels drop. This hormonal roller coaster will not only prepare and facilitate the release of the endometrial lining (menstruation, Day 1, end/beginning of another cycle), but also creates some other physiological and psychological discomforts.

What Does this Have to do with Sports Performance

Phrases like “it’s distracting” and “it’s just a bad day/week” are frequently used by athletes to justify poor performance associated with menstrual cycle symptoms.

You might have just realized that very important endocrinal processes happen daily in a woman’s body. For continuous cycles, hormones circulate in the blood; therefore, all over the body while affecting a whole range of functions such as: training physiological ability, recovery, muscles adaptation to training types, metabolism, need for fuel sources, risk of injuries, types and timings of symptoms, sleep, among others (Sims, 2016).

Findlay et al. (2019) conducted a study on female rugby players and 93% of athletes reported physiological and psychological menstrual cycle-related symptoms such as reduced energy levels, worry, distraction, fluctuating emotions, and reduced motivation affecting different aspects of daily lives and impaired performance. Some deal with it and others adapt and manage those symptoms through either self-medication or expert treatment. In a different sport, Heather Watson, a tennis player, even publicly announced that she had lost the Australian Open round do to “girl things.”

Considering all of these factors and associating them with different phases of the menstrual cycle, researchers were able to find a correlation between psychological and physiological availability for sports performance and menstrual cycle phases with the Follicular Phase being the most beneficial for high intensity work compared to Luteal Phase. We will explore this in Part III of this series.

Key Points:

  • The menstrual cycle has phases controlled by fluctuating hormones
  • Female athletes will benefit greatly by getting educated on the menstrual cycle and its nuances
  • Tracking and monitoring athletes’ menstrual cycles will allow coaches and athletes to create a good and accurate roadmap for a better and personalized training plan
  • Menopause, hormonal contraceptives, and pregnancy will create a huge hormonal imbalance and will need to be addressed individually and separately.
  • Being aware of endocrinal changes and their impacts on the overall health, wellbeing, and athletic performance will open new pathways for health and sports optimization

Useful Resources:

  • FitrWoman Website and App will allow the female athlete to track her cycle and symptoms and simultaneously correlate them with the physical and nutritional needs associated with the cycle phase the athlete is in.
    https://www.fitrwoman.com/
  • Roar by Stacy Sims Author of “Women Are Not Small Men” https://www.drstacysims.com/

References:

  • Findlay RJ, Macrae EHR, Whyte IY, Easton C, Forrest N e Whyte LJ. How the menstrual cycle and menstruation affect sporting performance: experiences and perceptions of elite female rugby players. Br J Sports Med. 2020 Sep;54(18):1108-1113. doi: 10.1136/bjsports-2019-101486. Epub 2020 Apr 29.
  • Pitchers, G. & Elliot-Sale, K. 2019, Considerations for coaches training female athletes retrieved from Issue 55/December 2019, Professional Strength and Conditioning, UKSA.
  • Sims, S. 2016, ROAR: How to Match Your Food and Fitness to Your Unique Female Physiology for Optimum Performance, Great Health, and a Strong, Lean Body for Life. 1st Edition, Rodale Books (2016)
  • General Information retrieved from:
    • https://www.fitrwoman.com/publications
    • https://mennohenselmans.com/menstrual-cycle-periodization/
    • https://www.cnn.com/2015/02/06/sport/heather-watson-tennis-sport-women-menstruation-period/index.html