Hormonal Health and Endurance Sports: What Every Female Athlete Should Know by Kathryn Melvin Women's Health APA Physiotherapist

Endurance sports like running and triathlons demand exceptional physical and mental resilience. But for women, there’s an additional layer to performance and wellbeing that often goes overlooked: hormonal health. As a pelvic health physiotherapist, I frequently see active women who are doing “everything right” with their training—yet struggling with fatigue, injuries, pelvic floor symptoms, or disrupted menstrual cycles. Often, the missing piece is understanding how endurance training interacts with the body’s hormonal system.

The Hormonal System: More Than Just Periods

Hormones regulate everything from energy levels and metabolism to bone density, recovery, mood, and pelvic floor function.

  • Oestrogen – supports bone health, muscle repair, and tissue elasticity (including the pelvic floor)

  • Progesterone – influences temperature regulation, breathing, and recovery

  • Cortisol – the stress hormone, elevated with intense or prolonged training

  • Leptin & insulin – regulate energy availability and metabolic function

When training load, nutrition, and recovery are well balanced, these systems work in harmony. When they’re not, disruption can occur.

Low Energy Availability: The Silent Saboteur

One of the most common issues in endurance athletes is low energy availability (LEA)—when energy intake doesn’t meet the demands of training and daily life. This doesn’t always mean disordered eating. Many women simply underestimate how much fuel their bodies need.

Over time, LEA can lead to Relative Energy Deficiency in Sport (RED-S), which affects:

  • Menstrual function (irregular or absent periods)

  • Bone density (increased stress fracture risk)

  • Hormonal balance

  • Immune function

  • Performance and recovery

Loss of a regular menstrual cycle is not a “normal” or harmless side effect of training—it’s a key warning sign.

The Menstrual Cycle and Performance

Understanding the menstrual cycle can help athletes train smarter, not harder.

  • Follicular phase (low progesterone, rising oestrogen):

    Often associated with higher energy, better strength gains, and improved recovery

  • Ovulation:

    Peak oestrogen may support performance—but ligament laxity may increase injury risk in some athletes

  • Luteal phase (higher progesterone):

    Core temperature rises, perceived exertion may increase, and endurance can feel more challenging

Not every woman experiences noticeable changes, but tracking symptoms can provide valuable insights.

Pelvic Health Considerations in Endurance Athletes

High-impact and high-volume training place significant load on the pelvic floor.

Hormonal fluctuations—particularly low oestrogen—can contribute to:

  • Urinary leakage during running

  • Pelvic heaviness or prolapse symptoms

  • Reduced tissue resilience and recovery

  • Increased injury risk

These symptoms are common—but not normal—and can often be improved with targeted physiotherapy and load management.

Top Practical Tips to Protect Your Hormones (and Performance)

This is where small, consistent habits make a big difference:

1. Coffee is not breakfast

Starting your day with just caffeine—especially before training—can increase cortisol and push your body further into an energy deficit. Aim to eat something, even if it’s small (e.g. toast, yoghurt, banana), before your morning coffee or run.

2. Avoid regularly training fasted

Running or riding on an empty stomach occasionally may suit some sessions, but doing it regularly—especially for long or high-intensity workouts—can contribute to low energy availability and hormonal disruption.

3. Don’t “earn” your food

You don’t need to wait until after training to fuel. Eating before and during sessions supports performance, reduces stress on the body, and protects your hormones.

4. Carbs are essential, not optional

Endurance athletes need carbohydrates for both performance and hormonal health. Chronically low-carb intake is a common driver of RED-S.

5. Fuel your recovery window

Try to eat within 30–60 minutes after training. This helps restore energy, supports muscle repair, and reduces overall physiological stress.

6. Watch the “double stress” load

Hard training + poor sleep + work/life stress = compounded cortisol load. Your body doesn’t separate these stressors.

7. Respect rest days

More is not always better. Recovery is where adaptation—and hormonal regulation—actually happen.

8. Your period is a vital sign

A regular menstrual cycle is a key indicator that your body is adequately fuelled and supported. If it’s missing or irregular, it’s worth investigating.

Red Flags to Watch For

Female endurance athletes should seek support if they experience:

  • Missed or irregular periods

  • Recurrent injuries or stress fractures

  • Persistent fatigue or poor recovery

  • Urinary leakage or pelvic pressure

  • Declining performance despite consistent training

Early intervention is key to preventing long-term consequences.

Final Thoughts

Endurance sport should enhance your health—not compromise it.

By understanding and respecting the role of hormones—and supporting your body with

adequate fuel and recovery—female athletes can train more effectively, reduce injury risk,

and perform at their best over the long term.

If you’re experiencing symptoms or unsure whether your training is supporting your health,

seeking professional guidance can make all the difference.

References:

Australian Institute of Sport. Relative Energy Deficiency in Sport (RED-S)

Shanley et al. (2023). Relative energy deficiency in sport: diagnosis and management in primary care

Lodge et al. (2023). Low carbohydrate availability and RED-S in female endurance athletes

Wood & Soundy (2025). RED-S systematic review and meta-analysis

Pengelly et al. (2024). Iron deficiency and performance in female athletes

Stuart McKayComment