Episode Details

We dive into the often-overlooked topic of amenorrhea: the absence of menstruation. Biomechanist Katy Bowman and biologist Dr. Jeannette Loram unpack the science with a focus on Functional Hypothalamic Amenorrhea (FHA) linked to energy deficiency in athletes. They explore how intense training and and sport pressures around leanness or weight can disrupt regular hormonal signals, affecting long-term bone density, cardiovascular health, and performance. They also discuss the original concept of the Female Athlete Triad (low energy availability, menstrual dysfunction, and low bone mineral density) and its evolution into RED-S (Relative Energy Deficiency in Sport), a more holistic model encompassing many aspects of health and wellbeing.

The conversation expands into evolutionary perspectives, comparing Western menstrual experiences—from menarche to menopause—with those of hunter-gatherer populations like the Hadza, and questioning what “normal” really means. Ultimately, this episode reframes intense athletics as a nuanced practice that must be supported by adequate nutrition and recovery.

Enhanced Show Notes and Full Transcript

00:00 – Intro & Sponsors

02:45 – What Is Amenorrhea?

05:40 – Primary vs Secondary Amenorrhea

09:00 – Functional Hypothalamic Amenorrhea (FHA): Energy deficiency and hormonal suppression

11:10 – Female Athlete Triad → RED-S: Evolution of understanding in sports science

21:30 – The Hadza perspective: menarche to menopause

25:25 – Negative consequences of amenorrhea: Bone Health  

29:15 – IUD induced amenorrhea 

37:00 – Historical and modern timelines for menarche compared to the Hadza 

50:45 – Closing thoughts on ancient humans 

Links & Research Mentioned:

Substack article that prompted this episode 

Dr Jen Gunter’s article on the hormonal IUD and bone health 

Foraging & Menstruation in the Hadza of Tanzania 

Comparison between The Female Athlete Triad & RED-S

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