Menstruation and cycling have a complicated history. Not that long ago, professional cycling was seen as largely a man's domain, so little attention was ever paid to female health. In recent years, the status of women's cycling has grown, but the conversation around health still had a way to go – not having a period at all was seen by some as a badge of honour, a sign you were lean and light, rather than a cause for concern.
Fast forward to now, though, and the growing focus on women's sport has also helped to improve and amplify the conversation and understanding around women's health, be that periods, pregnancy or anything else.
What are menstrual disorders?
'Menstrual disorder' is a wide, very generalised term that we can use to describe a whole host of problems that may be experienced by people born female, relating generally to their period, menstrual cycle, female hormones, or reproductive organs.
These disorders can be anything from unexplained, irregular or heavy periods (menorrhagia), to more specific and diagnosable problems like endometriosis, polycystic ovary syndrome (PCOS), fibroids and adenomyosis.
If you don't know what any of those words mean, or the specifics of the conditions, don't worry, you aren't alone. More than one in 10 women suffer from some kind of condition relating to their period, and at least 30% of reproductive-age women experience some kind of irregularity, but period health – or poor period health – is still an under-researched, under-discussed and often misunderstood topic.
So what are these conditions, and what do we know about how they affect women, particularly athletes? Whilst research is still sparse – and we'll get onto that next – Cyclingnews spoke to Jo Perkins from The Well HQ, a British-based project that works with various organisations to consult on and assist with understanding and coaching around female health for athletes, about how some of these conditions can manifest in the world of performance sport.
Endometriosis is a condition where cells and tissue that should grow in the lining of the uterus (the endometrium) grow elsewhere in the pelvis and abdomen, including around the reproductive organs, but also on the bowel or bladder, which can cause severe pain and heavy periods. It can be difficult to diagnose, and the only treatment is surgery to remove additional tissue, which can lessen symptoms in the short term but is not a permanent cure.
For athletes, the persistent pain of endometriosis can be at most debilitating, and at least performance-hindering at times. Whilst there is little to be done at present in terms of treatment, The Well are working to identify how athletes with endometriosis can be better supported, or at least make the conversation around it more constructive.
"Endometriosis is highly under-reported, especially with female athletes. It is common to see minimisation of their extreme pain, or the 'just push through' culture," Perkins explained. "Some of the ways it affects athletes are missing training sessions, having sub-optimal performance and feeling fatigued, but the psychological impacts cannot be dismissed: anxiety around races, selection and contracts, fear of heavy bleeding, bloating or that extreme pain on training or race day, [and] being perceived as unreliable."
PCOS, or polycystic ovary syndrome, is a hormonal condition where women experience higher levels of hormones, including testosterone, and multiple cysts on the ovaries. It can cause heavy periods, weight issues and excess body hair, as well as fertility issues.
In men's sport, higher testosterone is often associated with improved performance, with athletes even unnaturally elevating their levels (which is illegal); that doesn't mean hormone imbalances in women should be seen as a positive, though.
"Some studies show that increased androgens, normally testosterone, could present some benefits in terms of maximum oxygen uptake, better performance and some endurance tests, and that women with PCOS have higher muscle mass and better performance in certain tests, compared to women who don’t have it," Perkins said.
"However, having PCOS is far from being a positive thing – it’s a health condition that negatively affects many areas of these athletes’ lives. There are metabolic, reproductive and psychological challenges that come with it, such as insulin resistance, irregular cycles, fertility issues, and mood changes. The focus should be on health and managing the symptoms and the condition with specialised support."
Adenomyosis is described by the NHS as "a condition where the lining of the womb (uterus) starts growing into the muscle in the wall of the womb" and can be a cause for heavy or painful periods. Fibroids are benign growths that can grow in or around the uterus and can again cause heavy or painful menstruation.
Of course, there's also the problem of missing or losing periods altogether, which is all too common in elite athletes, and can have severe consequences, from RED-S to bone density problems caused by hormone deficiencies. We'll explore those elsewhere in this series.
Problems like these are wide-ranging, and all have different symptoms and treatments, so they shouldn't be treated as one or lumped together. For this article, we've focused on two of the most common and well-known conditions, endometriosis and PCOS.
There are not many cyclists – or athletes in general – who have openly spoken about having these conditions, but they do certainly affect women in the peloton.
"My understanding is that conditions such as endometriosis and PCOS absolutely exist within sport, including at elite level, but they are significantly under-recognised and under-diagnosed," said Meg Smith, a doctoral researcher at Loughborough University and Female Athlete Health Consultant at AG Insurance-Soudal.
"They’re often perceived as being rare in elite athletes, but I don’t think that reflects true prevalence. Instead, it reflects a combination of delayed diagnosis, symptom masking (particularly through hormonal contraception) and a sporting culture in which pain, fatigue and discomfort are frequently normalised. Many of the symptoms associated with these conditions, such as low energy availability, gastrointestinal issues, pelvic or lower back pain, and fluctuations in performance, can easily be attributed to training load or competition stress rather than an underlying medical condition.
"There’s also likely a degree of selection bias. Athletes whose symptoms are more severe may drop out earlier in development pathways, meaning elite sport can appear healthier than the wider population, even though that doesn’t reflect the full picture."
A dearth of research
Whilst organisations like The Well HQ and individual coaches and researchers are working hard to improve understanding of female athlete health and conditions that affect women, scientific or academic research is still very difficult to find.
Even in 2026, research into the effect of the regular menstrual cycle on performance is limited, with little conclusive evidence – there is not a widely agreed upon consensus on if and how the different stages of the cycle impact performance, either physiologically or perceptually.
With so little out there, even on the foundational level around period health and performance, sports-related studies around conditions like endometriosis and PCOS are nearly non-existent. A quick search will return some useful resources and articles on the subject – some anecdotal, some more academic – but still relatively little information, especially for athletes above the amateur level.
"Historically, sports science has been built around male physiological models. Female athletes were often excluded from research due to the perceived complexity of the menstrual cycle, which was seen as a confounding variable rather than something to be understood," Smith added.
"There has also been long-standing discomfort around discussing menstrual health, alongside practical challenges in funding, study design and longitudinal hormone measurement. As a result, it was often considered easier to control or suppress the cycle than to study it properly. That is changing, but we’re still catching up after decades of under-representation. The growing interest we’re seeing now reflects a recognition that female physiology isn’t a problem to work around but rather, it’s something fundamental to performance that deserves equal scientific attention."
Another possible barrier is that these conditions are highly individual, and do not necessarily affect all women in exactly the same way. Sports science often favours repeatability and consistent results, which can be hard to ascertain when it comes to women's health conditions – a study may not reliably prove or disprove a certain hypothesis.
This also means that it can be harder for athletes with disrupted periods to apply any of the current knowledge around the menstrual cycle, hormones and performance to their own lives.
"It can be more complex, largely because much of the existing research is based on relatively narrow models: typically, athletes with regular, ovulatory cycles and no diagnosed gynaecological conditions. In reality, many athletes don’t fit neatly into those categories," Smith said.
"When conditions such as PCOS or endometriosis are present, hormonal profiles can be less predictable, ovulation may not occur consistently, and symptoms may fluctuate independently of the traditional menstrual-cycle phases that are often discussed in research or applied practice. That doesn’t mean these athletes are ‘too complicated’ to understand, it means our current models don’t yet reflect the diversity of real-world female physiology. In those cases, support often needs to be far more individualised, focusing not just on cycle phase, but on symptoms, recovery, perception of effort and overall wellbeing."
The true number of riders racing with one of these conditions, whether they know it or not, may be inline with the number in the general population, but it's also likely that these conditions are underrepresented in sport, because they may act as a barrier to starting, participating in or sticking with a sport.
"It definitely does," Perkins said when asked if period problems can get in the way of sporting success. "It affects participation in terms of logistics, pain and fear of bleeding, stress. We have some studies that prove that 7 in 10 girls avoid being active during their period. In elite British track and field athletes, 76.8% reported that their menstrual cycle negatively affected their performance at some point during training or competition. And, among professional female rugby players in the UK, 87.8% perceived the menstrual cycle to negatively impact performance."
"If young athletes are repeatedly told that severe symptoms are ‘normal’ or something they simply have to push through, many will disengage before appropriate support is ever put in place," Smith added. "We often talk about increasing female participation in sport, but we rarely address the physiological experiences that can quietly push girls out."
If these are the numbers among female athletes in general, it's not hard to imagine that pain from endometriosis or consistently heavy or irregular periods caused by PCOS could only amplify the problem. So if there is a lack of these problems in the pro peloton, it may well be because riders stopped or faltered before they got there.
In the pro peloton
However, just because there may not be conclusive evidence or studies on the topic of conditions like PCOS or endometriosis, that doesn't mean there aren't anecdotal stories of how they can affect female cyclists.
The topic is far from a main talking point in women's cycling, but a small number of pros have spoken out about being diagnosed with conditions including PCOS and endometriosis. In 2019, Welsh track and road rider Elinor Barker spoke for the first time about her struggles with endometriosis, and how severe pain almost stopped her from competing. Dutch ProTeam rider Quinty Schoens is a former triathlete, but quit the discipline to focus on cycling after struggling with injuries and PCOS.
"I was also diagnosed with PCOS earlier this year. An abnormality on my ovaries, what still affects me on a regular basis," Schoens wrote on Instagram at the time. "This makes it hard to be at my highest level sometimes."
More recently, Spanish veteran Ane Santesteban made headlines for her candid comments about being diagnosed with endometriosis and ovarian cysts, and how long it took to understand the problem, with her coaches putting her performance dip down to mental factors.
"In 2024, I felt unwell all year; a lot of lower back pain, pain in one leg, and general discomfort," Santesteban explained to Cyclingnews. "I visited many doctors and had blood tests done, but we couldn’t find the cause of the pain. Many told me it was psychological, and after so many visits, I even started to doubt myself. But I still felt unwell.
"During a visit to the gynaecologist, they saw that I had a cyst on my right ovary, and that’s when they started asking questions, and we identified the problem. Everything stemmed from the fact that in December 2023, I had my hormonal IUD removed, and that’s when the pain began."
The reasons why riders like Santesteban sometimes struggle to find answers seem to stem from the fact that these conditions are misunderstood in the general population, let alone in sport. In researching for this article, I heard more than once from people working in performance at pro teams tell me they simply don't know enough about this topic, and therefore, it's probably not surprising that problems aren't being identified or managed appropriately.
"In my case, before every important race, I had to make certain visits to an osteopath, a pelvic floor physiotherapist, and do INDIBA treatment [a non-invasive radiofrequency therapy used in sports rehab to treat pain and inflammation]. That helped me a lot so my body could perform at 100%. Of course, I also made certain changes to my diet," Santesteban said about how she managed her condition.
But there is no easy fix, and riders may not always find the support they need at their first port of call – perhaps their coach or team doctor.
"In my experience, understanding varies hugely. Some coaches and practitioners are very engaged and keen to learn, while others feel unsure or uncomfortable, often because they’ve never received formal education on the topic," says Smith, who is one of a small number of female health specialists working in professional cycling.
"As a result, responsibility often falls on the athlete to raise issues themselves, which isn’t always easy in high-performance environments. Education is improving, but it’s still inconsistent, and much of the knowledge currently comes from individual interest rather than structured coach education systems."
"Many team doctors are excellent clinicians, but most will not have received formal training in female-specific sport endocrinology or menstrual health in performance contexts. As a result, menstrual and hormonal health can sometimes fall into a grey area – not quite medical in the traditional sense, and not quite performance – meaning it isn’t always fully owned by anyone," Smith continues.
"This can leave athletes feeling unsure about where to seek support. Improving this doesn’t require every practitioner to become a specialist, but it does require education, clearer pathways, and greater collaboration between medical and performance staff."
As for what riders themselves can do? "Visit the doctor and don't normalise menstrual pain or even amenorrhea [not having a period]," Santesteban said.
Will understanding grow?
In the medical world in general – let alone the sporting world – conditions like PCOS and endometriosis are still in a relatively nascent phase when it comes to diagnosis and treatment, so it's perhaps not surprising that the understanding is even less when it comes to athletes.
However, no matter how slow or belated the progress may be, the depth of knowledge around women's health conditions and how female athletes' bodies are different from their male counterparts is growing.
A rider like Santesteban, who has been racing since 2008, has seen the understanding around women's health in cycling grow and change, even before having her own experiences with more complicated conditions.
"I think that more and more importance is being given to women’s health in cycling. Before, it seemed that not having a period was a sign of good performance, when in fact it’s the complete opposite," she said.
"Fortunately, that has changed, and in recent years, one of the first things the team doctor and nutritionist ask you about is your menstrual cycle. Progress has been made. It’s true that endometriosis is still not talked about that much in general, but this too will change over time."
However, for her, her own diagnosis and the gradually improving situation in women's sport, it came too late. She called time on her career at the end of 2025.
"It has changed me a lot, both as a woman and as a professional cyclist," she said. "Living with pain and having to make so many doctor’s visits greatly affected my mental health, and I saw it as unfeasible to continue down that path for another year."
Organisations like The Well HQ are working specifically to improve the situation for women in sport – at all levels, from recreational to professional – by working with various federations, coaches and stakeholders, and change is slowly coming, though barriers remain.
Teams like AG Insurance-Soudal, where Meg Smith works specifically with riders and staff to focus on female athlete health, are leading the way in incorporating the menstrual cycle and more into their performance, coaching and culture.
"There’s more openness around conversations, greater interest in cycle tracking, and increasing recognition that athlete health can exist in parallel to performance. That said, progress is still uneven," Smith explained.
"In many cases, improvements are driven by specific individuals rather than embedded systems. At the moment, how well an athlete is supported often depends on whether the right people happen to be in the room, rather than on consistent organisational structures. This is an important aspect of performance at AG Insurance-Soudal, and we are working hard to find innovative ways to think about female physiology in order to best support our riders."
For all that things are far from ideal – the lack of research and understanding we found just in trying to write this article showed that knowledge on this topic remains minimal in professional cycling – there is a feeling that women's sport is on the right path.
"Things are definitely improving," Perkins said. "We are seeing more and more coaches and organisations committed to not only understanding the unique needs of female athletes, but to creating environments that truly support these women. They are seeking knowledge and guidance on how to properly train female athletes, and the ones who have already started to do this work have been seeing incredible results."
Just this month, Smith launched a survey on female athlete health in cycling, helping her team at Loughborough University to originate research into menstruation and performance in cycling. Other sports, like athletics, football and rugby, are taking women's health and female-specific training more seriously every year, with tangibly positive results.
As the focus on women's health improves, research into menstrual disorders will surely eventually follow, and riders who find themselves in the same position as Ane Santesteban or Quinty Schoens will find the support and knowledge they need sooner.
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