UNLABELLED: The literature has extensively investigated potential factors influencing women's performance, including the menstrual cycle and the circadian rhythm. However, review articles exploring the combined influence of both factors remain lacking in the literature. The study aimed to systematically review the literature on the relationship between the circadian rhythm and menstrual cycle on physical performance in women. The review followed the PRISMA guidelines. The search was performed on the Web of Science, PubMed, Scopus, SPORTDiscus, and Google Scholar databases. Of the 1205 records identified, four articles met the inclusion criteria. From four articles, two studies found a significant interaction between the time of day and phase of the menstrual cycle with physical performance. The isometric strength increased in the afternoon in the mid-luteal phase (versus the morning in the mid-luteal phase, p < 0.05), and the maximum cycling power was higher in the afternoon in the mid-follicular phase (versus the morning in the mid-follicular phase, p < 0.01). Our findings suggest that the time of day and the menstrual cycle phase affect physical performance, with the daytime potentially having a more significant influence. However, the results should be interpreted cautiously due to the limited studies and diverse methodologies used to monitor the menstrual cycle phase. This review reinforces the need for further investigation to understand better the combined effects of the circadian rhythm and menstrual cycle on women's physical performance. SYSTEMATIC REVIEW REGISTRATION: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=380965, identifier CRD42022380965.

• Keywords
• biological rhythm, daytime, endurance, female, ovarian cycle, strength,
• Publication type
• Journal Article MeSH
• Systematic Review MeSH

With increasing possibilities of multi-year missions in deep space, colonizing other planets, and space tourism, it is important to investigate the effects of space travel on human reproduction. This study aimed to systematically review and summarize the results of available literature on space travel, microgravity, and space radiation, or Earth-based spaceflight analogues impact on female and male reproductive functions in humans. This systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and Space Biomedicine Systematic Review methods. The search was performed using three databases: PubMed, Web of Science, and Medline Complete. During the database search, 364 studies were identified. After the study selection process, 16 studies were included in the review. Five studies included female participants, and the findings show an increased risk of thromboembolism in combined oral contraceptive users, decreased decidualization, functional insufficiency of corpus luteum, and decreased progesterone and LH levels related to space travel or its simulation. Male participants were included in 13 studies. In males, reproductive health considerations focused on the decrease in testosterone and sex hormone-binding globulin levels, the ratio of male offspring, sperm motility, sperm vitality, and the increase in sperm DNA fragmentation related to space travel or its simulation. Results of this systematic review highlight the need to focus more on the astronaut's reproductive health in future research, as only 16 studies were found during the literature search, and many more research questions related to reproductive health in astronauts still need to be answered.

• Publication type
• Journal Article MeSH
• Review MeSH