Women, hormones, and heart health in competitive sport

Female athletes may face unique heart-related considerations, including hormonal fluctuations, iron deficiency, and long-term cardiovascular outcomes.

For decades, the narrative around exercise and heart health has been reassuringly simple: the more you move, the better your cardiovascular outcomes (Myers et al., 2020). For women in competitive sport, however, the picture is far more nuanced.

Female athletes sit at the intersection of physiology, performance, and hormonal complexity. Their cardiovascular health is shaped not only by training load, but by fluctuating hormones, nutritional status, and life-stage transitions - from menarche to menopause (Zhu, Reed & van Spall, 2022). Understanding these interactions is essential - not just for performance, but for long-term heart health.

The hormonal dimension: more than just a “cycle”

Hormones are not a side note in female physiology. They are central to how the cardiovascular system functions.

Oestrogen, in particular, plays a protective role in heart health. It supports vascular function, influences lipid profiles, and contributes to endothelial health (Luo & Kim, 2016). In athletes, however, this protective effect is not always stable.

Low energy availability - common in endurance and weight-sensitive sports - can suppress reproductive hormones, leading to menstrual dysfunction. This is now recognised within the broader framework of Relative Energy Deficiency in Sport (RED-S), which affects multiple physiological systems, including cardiovascular function (Cabre et al., 2022). 

In practical terms, this means that low energy availability has potential to elevate cardiovascular risk in female athletes (Pope et al., 2024). A highly trained athlete with disrupted menstrual function may not be receiving the cardiovascular benefits typically associated with her training. In fact, oestrogen deficiency in younger athletes can mimic some features seen in postmenopausal women, including symptoms that overlap with cardiovascular concerns. 

At the elite level, hormonal disruption is not rare - it is often normalised. Yet its implications for heart health are still not fully understood, partly because female athletes remain underrepresented in cardiovascular research. 

The role of iron in oxygen delivery, performance, and the heart

If hormones set the physiological environment, iron determines how effectively that system functions. Iron is fundamental to oxygen transport, energy metabolism, and mitochondrial function - all critical to both performance and cardiovascular efficiency in athletes (Solberg & Reikvam, 2023).

Female athletes are disproportionately affected by iron deficiency due to a combination of menstrual blood loss, dietary patterns, and the demands of endurance training (Pedlar et al., 2017). The scale of the issue is striking. Up to 60% of female athletes may experience iron deficiency at some point, even in the absence of anaemia (Coates, Mountjoy & Burr, 2017). 

Importantly, the consequences extend beyond fatigue. Iron deficiency reduces aerobic capacity, impairs endurance, and increases cardiovascular strain during exercise (Pengally et al., 2025). Oxygen delivery becomes less efficient, meaning the heart must work harder for the same output. Even subclinical deficiency - before haemoglobin drops - can impair training adaptation and performance.

Recent commentary in endurance sport highlights that iron deficiency is not just a health issue, but a performance limiter - often overlooked until symptoms become pronounced (Kardasis et al. 2023). For clinicians and coaches, this creates a critical insight: persistent fatigue, reduced performance, or disproportionate heart rate responses during training may not be overtraining - they may be haematological.

The female athlete’s heart

The concept of the “athlete’s heart” - structural and electrical adaptations to training - is well established. But in women, these adaptations differ in important ways. Female athletes typically demonstrate smaller cardiac dimensions and different electrical patterns compared with male athletes, reflecting differences in body size, hormonal milieu, and physiology. 

Encouragingly, current evidence suggests that women may have a lower risk of certain adverse cardiac outcomes associated with lifelong endurance training, such as atrial fibrillation or myocardial fibrosis (Colombo & Finocchiaro, 2018; Castelletti & Gati, 2021). 

However, this should not lead to complacency. Because women have historically been underrepresented in sports cardiology research, our understanding of risk - particularly across different life stages - is incomplete (Zhu, Reed & van Spall, 2022). The assumption that high levels of exercise are universally cardioprotective may overlook important nuances, especially during periods of hormonal transition.

Life stages matter: from peak performance to menopause

One of the most overlooked aspects of female athlete heart health is timing.

Competitive years often coincide with peak reproductive years. During this period, menstrual dysfunction, low energy availability, and iron deficiency can intersect - creating a complex physiological environment that may influence both short-term performance and long-term cardiovascular health. As athletes transition into perimenopause and menopause, the picture shifts again.

Declining oestrogen levels are associated with increased cardiovascular risk in the general population (Fontaine et al., 2025). For athletes, this raises important questions: does a lifetime of training offset this risk? Or do hormonal changes alter the protective effects of exercise?

The evidence is still evolving. What is clear, however, is that menopause is not a neutral event in the cardiovascular trajectory of female athletes. It is a transition point that warrants attention - not dismissal.

Beyond performance: the long-term view

Perhaps the most important shift in thinking is this: female athlete health should not be judged solely by performance metrics.

A runner can be winning races while experiencing hormonal disruption. A cyclist can be training at elite levels with depleted iron stores. A master athlete can return to peak performance with hormonal support ... without fully understanding the cardiovascular implications.

These scenarios are not hypothetical - they are common.

Recent discussions in sport highlight that even fundamental aspects of female physiology, such as fertility and hormonal health, have historically been overlooked in athlete care. Heart health sits within this broader gap.

A more integrated approach

So where does this leave us? For female athletes - and those who support them - the goal should be integration, not fragmentation.

This means:

• Viewing menstrual health as a vital sign, not an inconvenience
• Routinely monitoring iron status, even in the absence of anaemia
• Recognising the cardiovascular implications of low energy availability 
• Considering life stage transitions, including menopause, in training and health planning
• Moving beyond male-based models of sports science and cardiology

Most importantly, it requires a shift in mindset: from performance at all costs, to performance within a framework of long-term health.

Final thoughts

Women in competitive sport are not simply smaller versions of men. Their cardiovascular health is shaped by a dynamic interplay of hormones, nutrition, and physiology - one that changes across the lifespan. The challenge for clinicians, coaches, and athletes alike is to recognise this complexity. Because when it comes to the female athlete’s heart, what you don’t see - or don’t measure - may matter just as much as what you do.

---

Frequently Asked Questions (FAQs)

Women, hormones, and heart health in competitive sport

Q. Do female athletes have different heart health risks compared with male athletes?
A: Yes. Female athletes experience unique influences on cardiovascular health, including hormonal fluctuations, iron deficiency, and life-stage transitions such as menopause, which can alter both risk and presentation.

Q. How do hormones affect heart health in female athletes?
A: Hormones—particularly oestrogen—play a protective role in cardiovascular function. Disruptions due to low energy availability or menopause can reduce this protection and influence heart health.

Q. What is the link between low energy availability and heart health?
A: Low energy availability, often seen in endurance or weight-sensitive sports, can suppress reproductive hormones (RED-S), potentially increasing cardiovascular risk despite high training levels.

Q. Why is iron important for both performance and heart function?
A: Iron supports oxygen transport and energy production. Deficiency can impair endurance, increase cardiovascular strain, and lead to higher heart rates for a given workload.

Q. Are female athletes at lower risk of heart problems like atrial fibrillation?
A: Current evidence suggests women may have lower rates of some conditions, such as atrial fibrillation, but research is limited and risk across life stages is not fully understood.

Q. How does menopause affect heart health in athletes?
A: Menopause is associated with declining oestrogen and increased cardiovascular risk. For athletes, this may alter the protective effects of long-term exercise and requires careful monitoring.

---

References

Cabre HE, Moore SR, Smith-Ryan AE, Hackney AC. Relative Energy Deficiency in Sport (RED-S): Scientific, Clinical, and Practical Implications for the Female Athlete. Dtsch Z Sportmed. 2022;73(7):225-234. doi: 10.5960/dzsm.2022.546.

Castelletti S, Gati S. 2021. The female athlete's heart: Overview and management of cardiovascular diseases. European Cardiology, 16: e47. doi: 10.15420/ecr.2021.29. PMID: 34950243. https://pmc.ncbi.nlm.nih.gov/articles/PMC8674625/

Coates A, Mountjoy M, Burr J. 2017. Incidence of Iion deficiency and iron deficient anemia in elite runners and triathletes. Clinical Journal of Sport Medicine 27(5): 493-498. doi: 10.1097/JSM.0000000000000390

Colombo CSSS, Finocchiaro G. 2018. The Female Athlete’s Heart: Facts and Fallacies. Current Treatment Options in Cardiovascular Medicine, 20: 101. https://doi.org/10.1007/s11936-018-0699-7.

Fontaine C, Gosset A, Davezac M, Buscato M, Grouthier V, Renault MA, Henrion D, Trémollières F, Schumacher S, Lenfant F, Arnal JF. 2025. From sex hormone decrease to hormonal treatment: impacts on cardiovascular risk with ageing, Cardiovascular Research, 121(10): 1551-1565, https://doi.org/10.1093/cvr/cvaf086

Kardasis W, Naquin ER, Garg R, Arun T, Gopianand JS, Karmakar E, Gnana-Prakasam JP. The IRONy in Athletic Performance. Nutrients. 2023; 15(23):4945. https://doi.org/10.3390/nu15234945

Luo T, Kim JK. 2016. The role of estrogen and estrogen receptors on cardiomyocytes: An overview. Canadian Journal of Cardiology, 32(8): 1017-1025. https://doi.org/10.1016/j.cjca.2015.10.021

Myers J, Kokkinos P, Arena R, LaMonte MJ. 2021. The impact of moving more, physical activity, and cardiorespiratory fitness: Why we should strive to measure and improve fitness. Progress in Cardiovascular Diseases, 64: 77-82. https://www.sciencedirect.com/science/article/abs/pii/S0033062020301833

Pope L, Roche DM, Marshall ZA, Alwan N, Webb RJ. 2024. The cardiovascular implications of low energy availability in physically fit female athletes: A systematic review. Proceedings of the Nutrition Society, 83(OCE4): E390. doi:10.1017/S0029665124006281.

Pedlar CR, Brugnara C, Bruinvels G, Burden R. (2018). Iron balance and iron supplementation for the female athlete: A practical approach. European Journal of Sport Science, 18(2), 295-305. https://doi.org/10.1080/17461391.2017.1416178

Pengally M, Pumpa K, Pyne DB, Etxebarria N. 2025. Iron deficiency, supplementation, and sports performance in female athletes: A systematic review. Journal of Sport and Health Science, 14: 101009. https://doi.org/10.1016/j.jshs.2024.101009

Solberg A, Reikvam H. Iron Status and Physical Performance in Athletes. Life. 2023; 13(10):2007. https://doi.org/10.3390/life13102007

Zhu JW, Reed JL, Harriette, van Spall HGC. 2022. The underrepresentation of female athletes in sports research: considerations for cardiovascular health, European Heart Journal, 43(17): 1609-1611. https://doi.org/10.1093/eurheartj/ehab846