Sources

Moonkeep's phase guide offers general wellness ideas, not medical advice. Research on training and eating by cycle phase is still limited, so the ideas are written as suggestions ("may help"), never as treatments. If anything about your cycle worries you, talk to a doctor, midwife or pharmacist.

The menstrual cycle

• American College of Obstetricians and Gynecologists (2015). Menstruation in girls and adolescents: using the menstrual cycle as a vital sign. Committee Opinion No. 651. Link
• Bull JR, Rowland SP, Scherwitzl EB, et al. (2019). Real-world menstrual cycle characteristics of more than 600,000 menstrual cycles. npj Digital Medicine 2:83. Link
• NHS. Periods and fertility in the menstrual cycle. Link

Ovulation, temperature and the fertile window

• Wilcox AJ, Weinberg CR, Baird DD (1995). Timing of sexual intercourse in relation to ovulation. New England Journal of Medicine 333:1517–1521. Link
• Frank-Herrmann P, Heil J, Gnoth C, et al. (2007). The effectiveness of a fertility awareness based method to avoid pregnancy in relation to a couple's sexual behaviour during the fertile time. Human Reproduction 22(5):1310–1319. (Describes the temperature-shift rule; Moonkeep is not a contraceptive.) Link

Pregnancy dating

• American College of Obstetricians and Gynecologists (2017). Methods for estimating the due date. Committee Opinion No. 700. Link

Movement and the cycle

• McNulty KL, Elliott-Sale KJ, Dolan E, et al. (2020). The effects of menstrual cycle phase on exercise performance in eumenorrheic women: a systematic review and meta-analysis. Sports Medicine 50:1813–1827. (Finds small, uncertain effects; Moonkeep's movement ideas are suggestions, not training rules.) Link

Food ideas

• NIH Office of Dietary Supplements. Iron: fact sheet for health professionals (iron needs and vitamin C and absorption). Link
• NIH Office of Dietary Supplements. Magnesium: fact sheet for health professionals (including premenstrual symptoms). Link
• Daily JW, Zhang X, Kim DS, Park S (2015). Efficacy of ginger for alleviating the symptoms of primary dysmenorrhea: a systematic review and meta-analysis of randomized clinical trials. Pain Medicine 16(12):2243–2255. Link

How Moonkeep uses them

The prediction method is described in How it works. Moonkeep is a wellness and record-keeping app. It is not a medical device and must not be used for contraception or diagnosis.