Why Women Were Taught to Be Proud of Losing Their Period (And How It's Destroying Female Athletes)

Stacy Sims introduces the 10-minute rule as a practical tool for women who struggle with the internal pressure to always complete a hard workout, often driven by external expectations. She explains that many women feel they must push through, but this can backfire. By giving yourself a brief trial period, you can objectively assess whether your body is capable of the planned intensity. If not, switching to recovery work prevents overstress and actually leads to better long-term gains. She emphasizes that this approach is not about laziness but about respecting the body's limited stress capacity. The rule also counters the cultural narrative that women must prove themselves by never backing down, a mindset rooted in the history of women in sport. Sims notes that heart rate variability, often used as a readiness metric, is unreliable across the menstrual cycle because progesterone naturally lowers HRV after ovulation, making it a poor indicator of what the body can actually do. Therefore, subjective feel combined with a short test is more effective.

Stacy Sims directly refutes the idea that high-intensity resistance training is detrimental to female hormone cycles. She traces the myth to two sources: a cultural bias against women in sport and a widespread failure to fuel adequately. She explains that sports originated as a male display of power, and women were excluded. When women entered high-performance spaces, any fallibility—like having a period—was used to put them down. As a result, women were proud to lose their periods, seeing it as proof they could compete with men. This cultural narrative made amenorrhea a badge of honor. The second factor is low energy availability: women simply weren't eating enough to support the training stress, leading to relative energy deficiency in sport (RED-S) and hormonal disruptions. So the training itself isn't the problem; it's the energy deficit. Sims notes that only in the last 4-5 years has it become acceptable to discuss menstrual cycles in professional sport, indicating how recent this shift is.