For decades, female athletes have been expected to train, eat, and recover like their male counterparts. But women are not small men—and when it comes to endurance sports like ultra running, embracing Female Physiology has unique advantages that deserve to be understood and celebrated.
Thanks to emerging research and voices like Dr. Stacy Sims, PhD, athletes, coaches, and healthcare professionals are rethinking how to structure training based on the menstrual cycle. This isn’t just empowering—it’s performance-enhancing.
Understanding the Menstrual Cycle: A Performance Roadmap to embracing Female Physiology
The menstrual cycle is a 28-day hormonal journey, divided into two main phases: the follicular phase (Day 1 to ovulation) and the luteal phase (ovulation to Day 28). Throughout these phases, hormones like estrogen and progesterone fluctuate, impacting energy levels, metabolism, hydration, and recovery.
By syncing your training to your cycle, you can work with your physiology, not against it.
Days 1–7: Menstruation & Early Follicular Phase – Go Hard
Hormone Levels:
Both estrogen and progesterone are at their lowest.
Best Training Focus:
High-intensity efforts like hill repeats, tempo runs, or heavy strength work.
Why It Works:
Low hormone levels mean fewer physical stressors. Your body is more efficient at recovering and producing power.
Ultra Running Tip:
Schedule your most demanding workouts or simulations of race pace during this window. You’ll feel stronger, recover faster, and build confidence.
Days 8–14: Late Follicular Phase – Peak Strength & Endurance
Hormone Shift:
Estrogen surges as your body prepares to ovulate.
Performance Boost:
Estrogen supports lean muscle development, better carb use, and sharper focus.
Training Ideas:
Long trail runs, back-to-back sessions, or fasted aerobic workouts.
Ultra Running Tip:
Test your race-day nutrition during this phase—Estrogen boosts your gut’s adaptability, lowering the chance of GI distress.
Days 15–28: Luteal Phase – Dial Back Intensity, Build Endurance
Hormonal Landscape:
Progesterone rises, core temperature increases, and recovery slows.
Body Cues:
You may feel bloated, fatigued, or less explosive.
Ideal Training:
Zone 2 steady-state runs, long hikes, or low-impact cross-training.
Ultra Running Tip:
Focus on electrolytes—progesterone increases sodium loss. Since estrogen promotes fat use, this phase is perfect for long-distance efforts that require fat adaptation.
Why Women Excel in Ultra Endurance Sports
Women are uniquely built to thrive in ultra-distance events—and science proves it.
Metabolic Efficiency
Estrogen enhances fat oxidation, helping women preserve glycogen during long races. This is crucial when aid stations or fuelling options are limited.
High Pain Tolerance
Research shows that women are better at managing sustained discomfort, an asset in events that test physical and mental limits over many hours.
Smarter Pacing
Women tend to start slower and finish stronger—a strategy that leads to higher finish rates and fewer injuries in ultra marathons.
Train With Your Physiology, Not Against It
If you’re an endurance athlete—or coaching one—tracking the menstrual cycle should be as important as logging mileage. By understanding how hormones affect performance, energy, and recovery, you can tailor training for peak results without burnout or injury.
Pro Tip:
Use a cycle-tracking app and journal how you feel week to week. Over time, you’ll see patterns that help inform smarter programming and self-care.
Conclusion: You’re Built for This
Ultra running isn’t just about grit; it’s about respecting your body’s signals. Women have an evolutionary advantage when it comes to endurance. With the right education and tools, you can embrace your cycle as a strength—not a setback.
You are not a small man. You are a force of nature. And you’re built to go far.
Looking to train smarter?
Download our free guide: “Train With Your Cycle” – Cycle-Based Mobility & Recovery Tips
Or book a personalised recovery session at our Neuromuscular & Sports Injury Clinic today.
*Inspired by the work of Dr. Stacy Sims, a leading researcher in female performance physiology and author of the groundbreaking book ROAR.