Cycle-based training is real science — and also an evolving one. Here's the work that shapes how Lune programs. We'll keep adding papers as the field grows.
Across 78 studies, performance dips during the early follicular phase (your period) are real — but small. What's big is the variation between women. This is why Lune uses recovery and symptom context alongside cycle phase instead of applying a one-size template.
Read on PubMed →The largest meta-analysis on oral contraceptives and performance found no meaningful gap between pill users and naturally cycling women — and no day-of-the-pill penalty. This is why Lune has a dedicated mode for hormonal birth control: instead of chasing phantom phases, it shifts programming to your daily recovery, symptom, and energy signals — the inputs that actually matter when your natural cycle is suppressed.
Read on PubMed →Same woman, one leg trained in follicular phase, the other in luteal. The follicular-trained leg gained more strength and more muscle diameter. This is part of the evidence behind why Lune scores imported programs against cycle context instead of pretending phase never matters.
Read on PubMed →Four months of cycle-periodized resistance training in trained women. Loading hard sessions into the first two weeks of the cycle beat both luteal-concentrated and evenly-spread training for several outcomes. This is the kind of periodization evidence Lune draws from when it frames training around cycle context.
Read on PubMed →The most recent critical review of the field. It suggests follicular-phase resistance training may produce better strength and mass gains, while also calling out the literature's real limitations. Lune takes that as a cue to treat phase as one input alongside recovery and symptoms — not as a rigid script.
Read on PubMed →68,758 women studied. Knee ligament laxity spikes during ovulation. Non-contact ACL injuries cluster outside the luteal phase. Oral contraceptives may cut injury risk by ~20%. The product takeaway for Lune is caution: this is a useful risk signal, but not a license to pretend every knee needs the exact same ovulation-week programming.
Read on PubMed →Your body burns fuel differently across the cycle — more fat oxidation and stronger endurance in the mid-luteal phase when the estrogen:progesterone ratio peaks. This is part of why cycle-aware coaching around training, recovery, and fueling context can matter.
Read on PubMed →A landmark review with a counterintuitive finding: when methodology is tight, your muscles aren't necessarily weaker on your period. The product takeaway is that menstruation alone shouldn't force a blanket "go easy" rule — context still matters.
Read on PubMed →Low energy availability — eating less than your training demands — suppresses reproductive hormones, accelerates bone loss, and tanks performance. This is an important risk in women's performance, but Lune does not currently diagnose or flag RED-S-style patterns in product.
Read on PubMed →The clinical foundation. Maps how estrogen and progesterone interact with metabolism, thermoregulation, psychology, and injury risk across every cycle phase. The phase ring you see inside Lune — menstrual, follicular, ovulatory, luteal, each with its own energy profile and training implications — traces directly back to papers like this one.
Read on PubMed →This field is still young relative to male-focused sports science. Some findings are robust (early-follicular performance dips are small, ovulatory knee laxity is real); others are active areas of debate. Lune errs toward individual adaptation over rigid templates, and we update our programming as the evidence moves.
Lune turns this work into adaptive, cycle-aware programming — without making you read the papers yourself.
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