This study aimed to investigate the difference in the prevalence, severity, and risk factors of dysmenorrhea between Japanese female athletes and non-athletes in universities. The participants were 18 to 30 years old with no history of a previous pregnancy and/or childbirth. After application of the exclusion criteria, the cohort comprised 605 athletes and 295 non-athletes. An anonymous questionnaire, which included self-reported information on age, height, weight, age at menarche, menstrual cycle days, menstrual duration, dysmenorrhea severity, sleeping hours, dietary habits, exercise habits, training hours, and competition level was administered. Compared with athletes, non-athletes had a higher prevalence of dysmenorrhea (85.6% in athletes, 90.5% in non-athletes, p < 0.05); non-athletes also demonstrated increased severity (none/mild 27.8%, moderate 19.3%, and severe 52.9% in athletes; none/mild 21.2%, moderate 17.2%, and severe 61.6% in non-athletes; p < 0.05). Factors related to severe dysmenorrhea in athletes included long training hours, early menarche, and prolonged menstrual periods. In non-athletes, short menstrual cycle days and extended menstrual periods were related to severe dysmenorrhea. The prevalence and severity of dysmenorrhea were higher among non-athletes than among athletes; different factors were related to severe dysmenorrhea in these two groups. Thus, different strategies are necessary to manage dysmenorrhea for athletes and non-athletes in universities.

About 10% of Japanese female athletes are afflicted by menstrually-related edema, mainly in the lower limbs, and, with few studies on this problem, the effect on performance remains unclear. To quantitatively evaluate fluid retention in the calf in female students over their menstrual cycle using magnetic resonance imaging (MRI) and to determine the relationship of MRI changes and athletic performance. The menstrual cycle was divided into 5 phases: menstrual, follicular, ovulatory, early luteal, and late luteal with sampling done in either morning (AM) or afternoon (PM) sessions. At each phase, MRI of the calf (7:00–8:00, 14:00–16:00), body composition and hormones (7:00–8:00), and athletic performance (14:00–16:00) were evaluated. 13 adult healthy Japanese female students with eumenorrhea. Estradiol levels decreased significantly in the menstrual phase and the follicular phase compared to the early luteal phase (P = 0.001, P = 0.024 respectively). Menstrual phase estradiol levels were significantly lower compared to the ovulatory phase (P = 0.015), and the late luteal phase (P = 0.003). Progesterone levels decreased significantly in the menstrual phase and the follicular phase compared to the ovulatory phase (P = 0.012, P = 0.009 respectively), the early luteal phase (both P = 0.007), and the late luteal phase (P = 0.028, P = 0.029 respectively), and it along with a significant decrease in the ovulatory phase compared to the early luteal phase (P = 0.010). AM T2 signals were significantly lower in the menstrual phase compared to the ovulatory phase (P = 0.043) but not other phases. PM T2 signals increased significantly in the menstrual phase compared to the follicular phase (P = 0.003), ovulatory phase (P = 0.009), and the late luteal phase (P = 0.032), and the difference between the AM and PM values increased significantly in the menstrual phase compared to the other 4 phases (P<0.01). A negative correlation between fluid retention and agility was observed. In female students fluid retention during the menstrual phase could be a factor that influences athletic agility.

Despite the World Anti-Doping Agency (WADA) ban on gene doping in the context of advancements in gene therapy, the risk of EPO gene-based doping among athletes is still present. To address this and similar risks, gene-doping tests are being developed in doping control laboratories worldwide. In this regard, the present study was performed with two objectives: to develop a robust gene-doping mouse model with the human EPO gene (hEPO) transferred using recombinant adenovirus (rAdV) as a vector and to develop a detection method to identify gene doping by using this model. The rAdV including the hEPO gene was injected intravenously to transfer the gene to the liver. After injection, the mice showed significantly increased whole-blood red blood cell counts and increased expression of hematopoietic marker genes in the spleen, indicating successful development of the gene-doping model. Next, direct and potentially indirect proof of gene doping were evaluated in whole-blood DNA and RNA by using a quantitative PCR assay and RNA sequencing. Proof of doping could be detected in DNA and RNA samples from one drop of whole blood for approximately a month; furthermore, the overall RNA expression profiles showed significant changes, allowing advanced detection of hEPO gene doping.

Introduction: Menstrual dysfunction, musculoskeletal injury, and poor nutrition combine to form the female athlete triad (FAT), which results in serious health consequences for affected athletes. To this point, the risk factors of this phenomenon have not been fully explored in Japanese female college athletes. Additionally, the effect of competitive level on FAT risk factors has also not been reported. Therefore, we aimed to examine FAT risk factors in Japanese female athletes of various sports as well as examine the impact of competitive level on FAT. Methods: A Japanese-language survey was completed by 531 athletes and 20 nonathletes at two Japanese universities and answers with regard to menstrual status, musculoskeletal injury, nutrition, and other variables were analyzed based on classification of the sports into nine distinct groups based on activity type. Sport intensity, training volume, and competitive levels were used to further classify each sport. One-way ANOVA and the Bonferroni post hoc test using SPSS were carried out to analyze significance for relationships between sport intensity and FAT risk factors. Additionally, the relationship between competitive level and FAT risk factors was analyzed by ANOVA and Bonferroni post hoc tests. Results: Sport intensity was positively correlated with a delay in menarche as well as dysmenorrhea and poor nutrition while musculoskeletal injury was correlated with repetitive, high-training volume sports. Lower competitive levels increased dysmenorrhea but did not impact injury status or nutrition. Conclusion: Sport intensity and training volume, but not competitive level, are the critical factors affecting FAT risk in Japanese female college athletes.

With the rapid progress of genetic engineering and gene therapy, the World Anti-Doping Agency has been alerted to gene doping and prohibited its use in sports. However, there is no standard method available yet for the detection of transgenes delivered by recombinant adenoviral (rAdV) vectors. Here, we aim to develop a detection method for transgenes delivered by rAdV vectors in a mouse model that mimics gene doping. These rAdV vectors containing the mCherry gene was delivered in mice through intravenous injection or local muscular injection. After five days, stool and whole blood samples were collected, and total DNA was extracted. As additional experiments, whole blood was also collected from the mouse tail tip until 15 days from injection of the rAdv vector. Transgene fragments from different DNA samples were analyzed using semi-quantitative PCR (sqPCR), quantitative PCR (qPCR), and droplet digital PCR (ddPCR). In the results, transgene fragments could be directly detected from blood cell fraction DNA, plasma cell-free DNA, and stool DNA by qPCR and ddPCR, depending on specimen type and injection methods. We observed that a combination of blood cell fraction DNA and ddPCR was more sensitive than other combinations used in this model. These results could accelerate the development of detection methods for gene doping.

With the rapid development of gene therapy technology in recent years, its abuse as a method of sports doping in athletics has become a concern. However, there is still room for improvement in gene-doping testing methods, and a robust animal model needs to be developed. Therefore, the purposes of this study were to establish a model of gene doping using recombinant adeno-associated virus vector-9, including the human erythropoietin gene (rAAV9-hEPO), and to establish a relevant testing method. First, it was attempted to establish the model using rAAV9-hEPO on mice. The results showed a significant increase in erythrocyte volume accompanied by an increase in spleen weight, confirming the validity of the model. Next, we attempted to detect proof of gene doping by targeting DNA and RNA. Direct proof of gene doping was detected using a TaqMan-qPCR assay with certain primers/probes. In addition, some indirect proof was identified in RNAs through the combination of a TB Green qPCR assay with RNA sequencing. Taken together, these results could provide the foundation for an effective test for gene doping in human athletes in the future.