Endurance Runner With Amenorrhea and a Marathon Goal
Client: 24-year-old female endurance runner, BMI 18.5, running 60–70 km/week with two interval sessions and one long run. She has had amenorrhea for 8 months, one prior tibial stress fracture, low libido, cold intolerance, and resting heart rate elevated from 48 to 58 bpm. She wants to run a marathon in 10 weeks and lose 2 kg to “run faster.” Her diet recall shows low energy intake, minimal dairy, and frequent training fasted. She reports fatigue but denies disordered eating. She has not seen a physician for the amenorrhea. She asks you to write a 10-week marathon plan and a meal plan to support performance. What do you do?
1. What concerns does this presentation raise, and what is your immediate action?
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This presentation suggests low energy availability and relative energy deficiency in sport: amenorrhea for 8 months, low BMI, prior stress fracture, fatigue, cold intolerance, low libido, elevated resting heart rate, high training volume, and fasted training. Immediate action is not to write a marathon plan. Refer to a physician and sports dietitian, screen for disordered eating with a validated tool, and consider mental health support. Explain that amenorrhea is not a normal training adaptation; it signals endocrine disruption and increased bone risk, especially with her stress fracture history.
2. How would you respond to her requests for a 10-week marathon plan and a 2 kg weight-loss meal plan?
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Decline the marathon plan for now and do not provide a weight-loss meal plan. Both goals conflict with restoring energy availability and bone health. Reduce training volume and intensity, eliminate fasted training, and prioritize recovery. Encourage regular carbohydrate intake around sessions, adequate protein, and calcium- and vitamin D-rich foods, but refer for individualized nutrition assessment rather than prescribing a rigid plan. Reframe success around restored energy, menstrual function, and injury-free running. If she resists referral, document the conversation and maintain clear boundaries.
3. What would medical clearance and return-to-sport criteria look like, and what is your role in that process?
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Return to sport should require medical clearance, improved energy availability, stabilized health, evaluation of menstrual function, no stress fracture symptoms, and a gradual increase in training over weeks to months with multidisciplinary follow-up. Your role is to coach within clear limits, support training modifications, and reinforce referral recommendations. You do not diagnose or treat relative energy deficiency in sport. If she continues to train despite symptoms, do not enable unsafe progression. Clear communication among physician, dietitian, mental health professional, and coach is essential.