Decreased muscle mass coupled with increased visceral fat mass is closely associated with an increased risk for exacerbating NAFLD pathophysiology.

BackgroundWhile aerobic training is generally recommended as therapeutic exercise in guidelines, the effectiveness of resistance training has recently been reported in the management of nonalcoholic fatty liver disease (NAFLD). Acceleration training (AT) is a new training method that provides a physical stimulation effect on skeletal muscles by increasing gravitational acceleration with vibration. AT has recently been indicated as a component of medicine. In this study, we evaluated the effectiveness of AT in the management of NAFLD in obese subjects.MethodsA total of 18 obese patients with NAFLD who had no improvement in liver function test abnormalities and/or steatosis grade after 12 weeks of lifestyle counseling were enrolled in an AT program. These patients attended a 20-minute session of AT twice a week for 12 consecutive weeks.ResultsDuring the AT program, the NAFLD patients showed a modest increase in the strength (+12.6%) and cross-sectional area (+3.1%) of the quadriceps, coupled with a significant reduction in intramyocellular lipids (−26.4%). Notably, they showed a modest reduction in body weight (−1.9%), abdominal visceral fat area (−3.4%), and hepatic fat content (−8.7%), coupled with a significant reduction in levels of aminotransferase (−15.7%), γ-glutamyltransferase (−14.4%), leptin (−9.7%), interleukin-6 (−26.8%), and tumor necrosis factor-α (−17.9%), and a significant increase of adiponectin (+8.7%). On a health-related quality of life survey, the patients showed an improvement in physical functioning (+17.3%), physical role (+9.7%), general health (+22.1), and social functioning (+6.0%).ConclusionAT reduced hepatic and intramyocellular fat contents and ameliorated liver function test abnormalities in obese patients with NAFLD, which was coupled with improved physical function and body adiposity. AT is clinically beneficial for the management of NAFLD.

Abstract:This study aimed to elucidate the key risk factors for shoulder pain in Japanese middle school-, high school-, and university-level badminton players and use a regression formula to predict the probability of shoulder pain onset based on risk factor combinations. Based on a self-report questionnaire survey, we included 461 individuals (102 middle school students, 134 high school students, and 225 university students) with a history of shoulder pain in the previous year and 541 individuals with no shoulder pain in the previous year. Then, we performed logistic regression analysis of individual characteristics and history of shoulder pain to analyze the factors associated with shoulder pain onset. Analysis of patients excluding those currently experiencing shoulder pain indicated that a history of shoulder pain (> 1 year previously) predicted shoulder pain onset. Analysis of patients excluding those with a history of shoulder pain indicated that undergoing care, being of university age, having a long history of competing, and short cool-down times were associated with recurrent pain. However, results were different for each age group. The fact that half the Japanese middle school, high school, and university badminton players had a history of shoulder pain suggests that they will experience recurrent shoulder pain. The results also suggest that different factors are important in each age group. Thus, it is critical to establish evidence-based countermeasures to prevent shoulder pain that interferes with play.

ContextAbout 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.ObjectiveTo 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.DesignThe 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.Participants13 adult healthy Japanese female students with eumenorrhea.ResultsEstradiol 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.ConclusionIn female students fluid retention during the menstrual phase could be a factor that influences athletic agility.

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 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.

This study aimed to identify factors associated with the prevalence and severity of menstrual-related symptoms. The protocol was registered in PROSPERO (CRD42021208432). We conducted literature searches of PubMed and Ichushi-Web and used the Jonna Briggs Institute critical appraisal checklist to assess the quality. Of the 77 studies included in the meta-analysis, significant odds ratios (ORs) were obtained for eight factors associated with primary dysmenorrhea (PD): age ≤ 20 years (OR: 1.18; 95% confidence interval [CI]: 1.04–1.34), body mass index (BMI) < 18.5 kg/m2 (OR: 1.51; 95% CI: 1.01–2.26), longer menstrual periods (OR: 0.16; 95% CI: 0.04–0.28), irregular menstrual cycle (OR: 1.28; 95% CI: 1.13–1.45), family history of PD (OR: 3.80; 95% CI: 2.18–6.61), stress (OR: 1.88; 95% CI: 1.30–2.72), sleeping hours < 7 h (OR: 1.19; 95% CI: 1.04–1.35), and bedtime after 23:01 (OR: 1.30; 95% CI: 1.16–1.45). Two factors were associated with severity of PD (moderate vs. severe): BMI < 18.5 kg/m2 (OR: 1.89; 95% CI: 1.01–3.54) and smoking (OR: 1.94; 95% CI: 1.08–3.47). PD severity (mild vs. severe) and prevalence of premenstrual syndrome were associated with BMI < 18.5 kg/m2 (OR: 1.91; 95% CI: 1.04–3.50) and smoking (OR: 1.86; 95% CI: 1.31–2.66), respectively. The identified risk factors could be utilized to construct an appropriate strategy to improve menstrual symptoms and support women’s health.

IntroductionMenstrual 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.MethodsA 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.ResultsSport 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.ConclusionSport intensity and training volume, but not competitive level, are the critical factors affecting FAT risk in Japanese female college athletes.

Chronic menstrual dysfunction and low female sex hormones adversely affect muscular performance in women but studies in college athletes are scarce. A cohort of 18 Japanese, female college athletes at the University of Tsukuba, Japan, were recruited and studied over 3 weeks under 2 conditions. One group had normal menstrual cycling (CYC, 9 athletes) while the other had irregular cycles (DYS, 9 athletes). Hormones and creatine kinase (CK) were measured from blood under both rest (RE) and exercise (EX) conditions. Biceps femoris tendon stiffness was measured by myometry. No differences in age, height, weight, menarche age, or one-repetition maximum weight existed between the groups. The DYS group had persistently low levels of estrogen and progesterone. In the CYC group, the CK level significantly increased at each point immediately post-exercise and 24 h post-exercise compared to pre-exercise in Weeks 1 and 2, and significantly increased at 24 h post-exercise compared to pre-exercise status in Week 3. The DYS group was significantly different only between pre-exercise and 24 h post-exercise over all 3 weeks. The DYS group also suffered from higher biceps femoris tendon stiffness at 24 h post-exercise. Chronic menstrual irregularities in Japanese college athletes increase muscle damage markers in the bloodstream and muscle stiffness after acute strength training.