Common, yes. Normalised in athlete culture, totally. But physiologically, functionally? No, definitely not.
Anyone of menstruating age who is an athlete or who trains regularly in any rigorous exercise is likely to experience period irregularities at some stage, or perhaps it's even your norm by now. This might look like extremely heavy, painful periods, periods with dark blood and lots of clotting, spotting in between periods, or maybe no periods at all. This usually occurs when there is a combination of stressors such as lots of exercise and energy expenditure with less energy intake (too little carbs or calories compared to the exercise). Unfortunately, this is all too common in the athletic industry. Throw in some intermittent fasting, poor sleep, and literally anything that creates stress in daily life, and you have the perfect recipe for hormone dysfunction.
But exercise is healthy right?
Definitely. Exercise is super important. When we don't move enough, we get stagnant, we don't get fresh blood circulating, we don't sleep as well, we get depressed, etc. etc. That said, we have to think of exercise as a type of stress. Stress, while usually considered something to avoid, is something we actually need, but you have to look at it like an upside down bell curve. Too little stress leaves us unmotivated and lacklustre. A bit of stress gets us up and going, it gives us drive to take action. If stress keeps increasing though, our productivity and functioning starts declining again as we get burnt out and use up all of our resources. Exercise is generally considered healthy because of its positive attributes, but we have to remember that our brains think the reason our heart rate is skyrocketing and our blood is surging through our veins is because we're in danger. Exercise is stress.
When does being an athlete become unhealthy?
If exercise is your one and only stressor, you can probably go a bit harder and reap the benefits without burning out. These days, it's really unlikely for that to be the case. Screen time, poor, sleep, restrictive diets, artificial lighting, EMFS, treated water, pesticides, off gassed chemicals from buildings, furniture, clothing etc., pollution, all stress, stress is all around. Not to mention any interpersonal relationship stress, worries about the past or future, your job, your health, family struggles, paying bills, cleaning your house... it adds up. So, a little bit of stress, good. A lot of stress... you get the picture now. It's pretty difficult to eliminate stress in our lives, so if you're adding a big one like extreme physical exercise, it can have some major consequences.
Okay, I get why I'm stressed now, but why exactly does that make my period irregular?
Good question. People blabber on about stress all the time, but it doesn't really tell us how that messes with our hormones and our monthly cycle.
In the simplest of terms, athletes tend to use up a lot of "energy" by training, so "energy intake" needs to be sufficient to account for that. We need energy, in the form of caloric support, to make the hormones that not only regulate our cycle, but also help us recover, repair tissues, and maintain strong bones. Athletes who have menstrual irregularities also report a much higher percentage of severe musculoskeletal injuries than those with a normal cycle.
A hormone modulator called leptin also tends to be low when energy intake is low, which directly affects production of cortisol, growth hormone, and thyroid stimulating hormone, which ultimately disrupts tissue growth and repair. Female athletes who don't get their period tend to have lower caloric intake, and lower levels of leptin, and less ability to mediate reproductive function. Basically, the tendency for female athletes to have both menstrual issues and tissue injuries is not unrelated, as the same hormones are needed to regulate both.
When women are menstruating regularly, it indicates proper hormone function, essentially a proper hypothalamic-pituitary axis and a normal uterus. Weight loss, over exercising, and stress in general throw these out of whack. Functional hypothalamic amenorrhea is a condition when the HPA axis is not working properly, and affects roughly 40% of athlete women, much higher than the 5-11% in non-athletic women.
While proper energy intake is obviously important for high performance sports, it can be difficult to take in enough caloric sport if you need to cut weight for a competition, or if your sport has idealised low body fat. So what happens? Energy intake is severely limited, exercise levels remain high, and the risk of menstrual dysfunction and poor bone health goes up.
Functional hypothalamic amenorrhea
Functional hypothalamic amenorrhea, known commonly at "athletic amenorrhea" is essentially defined as loss of period due to intense training. But it is much more than just the loss of a period. It is a disturbance to an important functional mechanism of the body, which looks after menstruation, called the Hypothalamic-pituitary-gonadal axis (HPG). When this happens, there is a reduction in release of gonadotropin-releasing hormone from the hypothalamus, which reduces luteinizing hormone and follicle stimulating hormone from the pituitary, which results in reduced sex steroids produced by the ovaries, and eventually loss of ovulation and menstruation.
While the axis influences the menstruation, it does so by way of regulating hormones, as a major player in the body's stress response. The HPA axis (A for adrenal) is one mechanism that inhibits the HPG causing the situation above, which is often triggered by exercise-induced secretion of corticotropin-releasing hormone and cortisol. These are considered major stress hormones which inhibit GnRH secretion by the hypothalamus as described above.
In addition, a hypometabolic state is common in athletic amenorrhea cases, which is presented with low insulin and insulin-like growth factor 1 (IGF-1), with high levels of growth hormone. IGF-1 is needed for normal levels of GnRH and LH, so these too are reduced.
In summary, loss of period in athletic amenorrhea is from inhibition of hormone modulating mechanisms due to stress hormones and endorphins induced by exercise, when energy intake is less than expenditure, as is common in many sports who value low body fat for weight-divisions, endurance, and even aesthetics.
So what can I do about it? Are you saying I can't be an athlete and have a healthy cycle?
All hope is not lost. You can definitely be an athlete. I am one myself. For some, being an athlete is their career, for others, a necessary outlet, community, therapy, sense of purpose. In many ways, exercising and training is really good for us.
The point here is not to scare people out of intense training and hard work, but rather provide information that helps us understand how to marry these lifestyles with longevity and prevention, or reversal, of major health consequences. It's all about reducing the stress we can control. Don't quit sports, be who you are, just mitigate the harm. How, you say?
Start by taking the stress out of your diet. Eat! Eat properly, eat enough, eat often. This means so many things in diet culture today, so it's important to work with a practitioner who understands female physiology as well as what is asked of you as an athlete (I focus on this at Functional Chinese Medicine in Melbourne). This may require dropping the vegan, paleo, keto, carnivore etc., extreme fasting, or carb and calorie restriction, even if it's supposed to be a useful "biohack". Hacking is a shortcut and in this case, comes at a price. Eat when you wake up so your body doesn't produce stress hormones by thinking it's going to starve today. Eat carbs around heavy training for fuel, and quality fats and proteins for nutrients. Don't make your body work hard to extract or make what it needs to power you.
You truly do need to sleep. This can be a long article by itself, just like all of these pointers. But you have to do it. Not only is it essential for all of our functional processes to work properly, it is also extremely integral for neuroplasticity. So if you're learning skills and techniques that you want to apply to your sport, sleep is going to help you learn, it's going to help you recover, and it's going to aid in proper hormone regulation.
Manage life stressors. Again, easier said than done. But truly, are there aspects of your life that are seriously compromising your wellbeing, that are also negotiable? There are always difficult consequences to ending shitty relationships, leaving awful jobs, or moving out of mouldy houses, but they are things that must be done sooner or later. Take those stressors out so you can pursue your goals that involve stressors like exercise and competition.
See a practitioner. Get help. You aren't supposed to be a pro athlete as well as a doctor or clinician. Get some assistance in figuring out your diet and changing parts of your lifestyle to suit your needs. In my practice at Functional Chinese Medicine in Melbourne, I use acupuncture, herbs and supplements to give athletes a leg up, but a big part of treatment is getting them eating in a way that actually feeds the body. Eating properly can be scary at first, especially in the sport culture today of weight cuts and leanness as a sign of discipline and accomplishment. We also work on issues that may have started in childhood, but are holding them back in their training and life in general. Some of these changes are harder than others, but when your period regulates and you aren't tired and hungry any more, and you really start to feel good, you probably won't look back.
References:
Cialdella-Kam, L., Guebels, C. P., Maddalozzo, G. F., & Manore, M. M. (2014). Dietary intervention restored menses in female athletes with exercise-associated menstrual dysfunction with limited impact on bone and muscle health. Nutrients, 6(8), 3018–3039. https://doi.org/10.3390/nu6083018
Hirschberg A. L. (2020). Female hyperandrogenism and elite sport. Endocrine connections, 9(4), R81–R92. Advance online publication. https://doi.org/10.1530/EC-19-0537
Thein-Nissenbaum, J. M., Rauh, M. J., Carr, K. E., Loud, K. J., & McGuine, T. A. (2012). Menstrual irregularity and musculoskeletal injury in female high school athletes. Journal of athletic training, 47(1), 74–82. https://doi.org/10.4085/1062-6050-47.1.74
Thong, F., McLean, C. & Graham T. (2000). Plasma leptin in female athletes: relationship with body fat, reproductive, nutritional, and endocrine factors. Journal of applied physiology, 8, 6, 2037-2044. https://doi.org/10.1152/jappl.2000.88.6.2037
La Vignera, S., Condorelli, R. A., Cannarella, R., Duca, Y., & Calogero, A. E. (2018). Sport, doping and female fertility. Reproductive biology and endocrinology : RB&E, 16(1), 108. https://doi.org/10.1186/s12958-018-0437-8
Get in touch if you want to discuss hormones, sports medicine, female athletes, and Chinese Medicine in Melbourne or remotely.
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