Did you know that the menstrual cycle is the ‘fifth vital sign’ of health? Yep, that monthly hormonal journey sits alongside blood pressure, heart rate, body temperature and respiration rate to provide a powerful database of information on your bone health, ovarian health and long-term fertility.

Though the importance of the menstrual cycle was first acknowledged by researchers in the early 2000s, for many years, societal shame and stigma has created a body literacy crisis. How many of us can say that we were taught enough about hormonal health at school, or were brought up to see periods as positive? It’s not surprising to learn that, according to a 2022 study, 78% of students reported being taught more about the biology of frogs than the human female body.  

Thankfully, the last five years has seen important progress in the conversation around menstrual health with an explosion of resources, research and public health campaigns. Over 50 million women globally now monitor their monthly cycle, while cycle syncing – a trend which involves changing your diet, exercise routines and other lifestyle habits based on your menstrual cycle – has received over 300 million views on TikTok.

Though the efficacy of cycle syncing varies from person to person, experts generally agree that understanding the way our hormones can impact our lives (from mood and energy to gut health and sleep) empowers women to make autonomous reproductive health decisions. It also helps us to behave more kindly to our bodies – something that’s particularly true for women who regularly exercise, as monitoring hormonal fluctuations can help them to make sense of, and respond to, changes in sports performance throughout the month. 

So far, so good. But there is a stumbling block. Period loss, known as secondary amenorrhea, is a growing issue in the UK. It’s estimated that period loss due to excessive exercise, known as functional hypothalamic amenorrhea (FHA), now affects around 44% of vigorously exercising women – putting them at heightened risk of infertility, osteoporosis, psychological stress and cardiovascular disease.

As someone who developed FHA at 15 thanks to intensive athletics training, I know only too well how disenfranchising and anxiety-inducing losing your period can be. With the majority of conversation and menstrual tracking resources reliant on users being able to share information about their period, I’ve been left wondering if I have any means of tuning into my hormones. Do I even have a menstrual cycle?

Numerous hospital visits and countless blood tests have done little to shed light on the situation, with some doctors suggesting that I have “next to no” oestrogen while others believe that my hormone levels sit within normal range.

To help uncover what’s really going on hormonally for women who have lost their period, I’ve been speaking to sports dietitian, women’s health expert and author of More Fuel You, Renee McGregor. 

McGregor explains that the reason women with FHA aren’t able to track their menstrual cycle is because there isn’t actually a cycle occurring. “When a woman loses her period due to FHA, it usually means that for some functional reason, the hypothalamus has down-regulated its activity. That means the reproductive hormones are no longer working and, as such, she is not ovulating and no hormonal cycle is taking place.”

She adds that this can sometimes become confusing for women with FHA who use hormonal contraception such as the hormonal IUD or who may experience some hormonal activity throughout the month. However, she explains that even these women will find it difficult to track any genuine hormonal changes, unless they’re having weekly blood tests (which isn’t practical or accessible for many).

But, McGregor explains, that doesn’t mean that we’re automatically free from  experiencing premenstrual symptoms. “When someone has started to make modifications to their lifestyle such as changing their diet, exercise patterns or managing their stress, women can start to experience some cyclical symptoms. The most common indicator that your hormonal cycle is returning will be breast tenderness, increased vaginal mucus and sometimes mood fluctuations.” 

She reiterates that although this can happen some months before the menstrual cycle returns, it will only take place when your recovery is well underway and ovulation is nearby. 

“I think that would be impossible to do”, admits McGregor, “because you just wouldn’t know where you are. It’s also unlikely that women with amenorrhea would experience any of the benefits of cycle syncing.”

Functional hypothalamic amenorrhea, she says, is usually related to high intensity exercise or fasted training putting too much stress to the body. As such, the key to recovery is often changing the way you exercise. 

“The important thing to remember is that that FHA is problematic,” she says, “and usually occurs because there is too much stress in the body. It really does need to be resolved before someone considers increasing training or committing to a goal. Women with FHA should be very mindful about exercise, and I would definitely advise working with a professional who can devise an appropriate exercise plan.”

Ultimately, amenorrhea is one of the most powerful tools your body has for letting you know that your health isn’t where it should be. But, it’s important to know that FHA is reversible, and the first step to recovery should be to speak with your GP or healthcare professional.

Images: Getty