Should Women Train Differently Across the Cycle? Understanding energy, hormones and strength

Sims believes that the most robust way to ensure progress and health is to centre strength training. She emphasizes that consistency trumps any supposed hormonal advantage of timing certain workouts to specific phases. Her clinical framing is straightforward: resistance work is always in, regardless of what else is going on. This approach removes the guesswork for women who are uncertain about their cycle status and prevents the phenomenon of doing less because they are waiting for a ‘green light’ from a plan that doesn't match their reality. The protocol is not about ignoring cycle-related feelings; rather, it sets a fixed anchor around which other training can be flexibly arranged.

Sims contrasts the social media narrative of ‘must do X in follicular, Y in luteal’ with the reality that many women have anovulatory cycles or simply don't know their phases. She introduces the concept of grace: acknowledging that on your period, in your follicular phase, or late luteal phase, your best might look different, and that's acceptable. The protocol essentially splits the week into strength days (fixed) and other days (adaptive). By allowing women to respond to daily signals, it prevents the demotivation that comes from failing to hit prescribed metrics when feeling flat, while still maintaining the habit of physical activity. Importantly, she frames this as a way to avoid overall exercise decline—'doing something and moving your body is still ultimately, we're all going to agree, better than sitting on the couch.'

Sims responds to the question of where in the cycle women typically have more energy. She pinpoints the 5–7 days before ovulation as the most reliable window, driven by rising estrogen. During this time, the body exhibits physiological advantages: heart rate variability is improved, resting heart rate drops, core temperature is lower (aiding heat dissipation), the immune system is less pro-inflammatory, and carbohydrate utilization is ramped up. This combination makes high-intensity efforts more accessible and effective. However, she quickly adds nuance: some women feel fantastic right on ovulation day due to the estrogen surge, while others feel a transient crash as the follicle ruptures and estrogen dips—some even experience severe pain (mittelschmerz) that makes exercise impossible. Similarly, the early luteal phase (day 16–22) is variable; some maintain high energy, others can't hit high intensities. Late luteal (day 24–27) brings PMS, cramping, and fatigue for many. Therefore, the protocol is not to blindly follow a calendar but to place your hardest training on days you objectively feel you can perform. The risk of ignoring feel is that a poor-quality session won't provide the necessary stimulus, wasting effort and potentially reinforcing negative associations with training.

Sims repeatedly returns to the problem of not knowing ovulation status. She notes that up to 15% of cycles are anovulatory, and countless women are simply unaware of when their follicular or luteal phases occur. This ignorance makes any generic training directive irresponsible. The solution is to gather one's own data—combining objective signs of ovulation with subjective symptom tracking—so that training can be aligned with personal physiology. She acknowledges that even with data, the picture is messy: some women feel great on ovulation, some feel awful, and symptoms vary cycle to cycle. Still, data accumulation sharpens the ability to plan and, crucially, to apply grace when the expected high-energy day doesn't materialise. For those who cannot or do not wish to track meticulously, the fallback is the strength-core + feel-based model.

Sims opened by acknowledging that five years ago she would have said yes to cycle-based training. However, the critical missing piece is knowing whether a woman actually ovulates. She references statistics (likely from her colleague) that a significant proportion—'15% of patients'—are not ovulating, and many others have no grasp of their follicular or luteal phases. The danger she identifies is that when women are given rigid phase prescriptions, they may end up doing overall less exercise: they wait for the ‘right’ phase to do a certain workout but never feel confident about when that is, or they skip because the prescribed intensity doesn't match their energy. This undermines consistency, which Sims underscores as the cornerstone of building muscle and strength. Consequently, her current clinical stance is to make resistance training the unwavering core, regardless of phase, pregnancy, or fertility status, and to permit flexibility on other days based on subjective feel. She also notes that many women suppress their cycles with hormonal contraceptives and were never taught normal cycle fluctuations, making them especially vulnerable to confusing social media messages that claim absolute rules. The overarching shift is from prescriptive, phase-locked training calendars to a model of personal data tracking, self-compassion, and consistency.