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Yu Kawasaki,1 Takatoshi Kasai,2– 5 Yuko Sakurama,6 Fusae Kawana,2 Nanako Shiroshita,2 Natsue Koikawa6,7 1Department of Obstetrics and Gynecology, Juntendo University Graduate School of Medicine, Tokyo, Japan; 2Cardiovascular Respiratory Sleep Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan; 3Department of Cardiovascular Management and Remote Monitoring, Juntendo University Graduate School of Medicine, Tokyo, Japan; 4Department of Cardiovascular Biology and Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan; 5Sleep and Sleep-Disordered Breathing Center, Juntendo University Hospital, Tokyo, Japan; 6Japanese Center for Research on Women in Sport, Juntendo University, Tokyo, Japan; 7Graduate School of Health and Sports Science, Juntendo University, Chiba, JapanCorrespondence: Takatoshi Kasai, Department of Cardiovascular Biology and Medicine, Juntendo University Graduate School of Medicine, 3-1-3 Hongo, Bunkyo-ku, Tokyo, Japan, Tel +81-33813-3111, Fax +81-5689-0627, Email kasai-t@mx6.nisiq.netPurpose: Female athletes with menstrual abnormalities have poor sleep quality. However, whether female athletes with poor sleep quality based on subjective assessment have distinctive changes in objective measures of sleep in association with menses remains unclear. This study aimed to compare changes in objective sleep measurements during and following menses between collegiate female athletes with and without poor subjective sleep quality.Patients and Methods: Female collegiate athletes (age range/mean ± standard deviation: 18– 22/ 22.2± 1.1) with regular menstrual cycles were recruited. The participants underwent home electroencephalogram monitoring during the first and second nights after the onset of menses and one night between the seventh and 10th nights after menses onset (mid-follicular phase). The Pittsburgh Sleep Quality Index (PSQI) was used to assess the subjective sleep quality. Interactions between the presence of poor subjective sleep quality (ie, PSQI ≥ 6) and changes in objective measures of sleep in association with menses were analyzed.Results: Data of 45 athletes, including 13 with poor subjective sleep quality, showed that changes in arousal index in athletes with poor subjective sleep quality were distinctive from those in athletes without poor subjective sleep quality (p = 0.036 for interaction). In athletes with poor subjective sleep quality, the arousal index was significantly increased in menses (p for analysis of variance, 0.015), especially on the first night after the onset of menses compared with during the mid-follicular phase (p = 0.016).Conclusion: Collegiate female athletes with regular menstrual cycles are likely to have poor subjective sleep quality in association with more frequent arousal during the first night after the onset of menses than during the mid-follicular phase.Keywords: electroencephalogram, menstruation, Pittsburgh sleep quality index, sports, women

Yu Kawasaki,1 Takatoshi Kasai,2– 5 Yuko Sakurama,6 Akiko Sekiguchi,6 Eri Kitamura,1 Itsuki Midorikawa,7 Nanako Shiroshita,4 Fusae Kawana,3 Etsuko Ogasawara,6,8 Mari Kitade,1,6 Natsue Koikawa,6,8 Takao Matsuda9 1Department of Obstetrics and Gynecology, Juntendo University Graduate School of Medicine, Tokyo, Japan; 2Department of Cardiovascular Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan; 3Cardiovascular Respiratory Sleep Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan; 4Department of Cardiovascular Management and Remote Monitoring, Juntendo University Graduate School of Medicine, Tokyo, Japan; 5Sleep and Sleep-Disordered Breathing Center, Juntendo University Hospital, Tokyo, Japan; 6Japanese Center for Research on Women in Sport, Juntendo University, Tokyo, Japan; 7Akita Northern Happinets, Akita, Japan; 8School of Health and Sports Science, Juntendo University, Chiba, Japan; 9Department of Gynecology, National Hospital Organization Nishi-Beppu National Hospital, Oita, JapanCorrespondence: Takatoshi Kasai, Department of Cardiovascular Medicine, Juntendo University Graduate School of Medicine, 3-1-3 Hongo, Bunkyo-ku, Tokyo, Japan, Tel/fax +81 3-6873-2869, Email kasai-t@mx6.nisiq.netPurpose: Sleep is an essential factor for athletes, and it is important to intervene in sleep to manage it. We need a device that can evaluate sleep easily and constantly. Consumer wearable devices can be useful tools for athletes. In order to use consumer wearable devices in clinical research, it is essential to conduct a validation study. Thus, we conducted a validation study to assess the Fitbit Alta HRTM (FBA)- a consumer wearable device with an accelerometer and a heart rate monitor to detect sleep stages and quality against electroencephalographic (EEG) studies in athletes.Patients and Methods: Forty college athletes participated in the study. EEG was applied to participants simultaneously while wearing FBA.Results: Regarding sleep parameters, there was a strong correlation between the total sleep time (TST)-EEG and the TST-Fitbit (r = 0.83; p < 0.001). Regarding the sleep stages, there was a modest correlation between the N3 sleep-EEG and the N3 sleep-Fitbit (r = 0.68; p < 0.001). In addition, there was a strong correlation between the percentage of N3 sleep in between sleep onset and initial rapid eye movement sleep-EEG and those on Fitbit (r = 0.73; p < 0.001).Conclusion: These results demonstrate that FBA facilitates sleep monitoring and exhibits acceptable agreement with EEG. Therefore, FBA is a useful tool in athletes’ sleep management.Keywords: athletes, wearable technology, sleep monitoring, electroencephalogram

Athletes become increasingly susceptible to infection with intense training that results in immune suppression. The immune state was investigated after administering cystine/ theanine (CT), which has been reported to have [...]

In the present study, we conducted a placebo-controlled, double-blind, parallel-group comparison trial in which an extract of Cordyceps militaris (CM) mycelium was administered to long-distance runners for 16 weeks during the pre-season training period and blood test markers for anemia were investigated. The results indicated that the change rates of serum ferritin levels were moderately increased in the CM group ( n = 11) but decreased in the placebo group ( n = 11) during the study period, and the levels were significantly increased in the CM group compared with those in the placebo group at 4 weeks and 8 weeks after the test food intake ( p < 0.05). Moreover, the change rates of hemoglobin and hematocrit were significantly increased in the CM group compared with those in the placebo group at 8 weeks after the test food intake ( p < 0.05). These observations suggest that the intake of test food containing Cordyceps militaris mycelium extract is expected to effectively maintain the hemoglobin and hematocrit levels in long-distance runners, possibly via the suppression of the decrease in iron storage, which is reflected by serum ferritin, during pre-season training. Furthermore, the levels of creatine kinase were increased above the normal range in both the placebo and CM groups at registration. Interestingly, the creatine kinase levels were significantly decreased in the CM group compared with those in the placebo group at 16 weeks after the test food intake ( p < 0.05). These results suggest that Cordyceps militaris mycelium extract exhibits a protective action on the muscle damage observed in long-distance runners and may suppress muscle injury. Together, these observations suggest that Cordyceps militaris mycelium extract exhibits an improving effect on the markers for not only anemia, but also muscle injury in long-distance runners during pre-season training.

Sleep is essential for athletes to recover physical fitness. It has been suggested that sleep is affected by muscle volume. Compared to female athletes, male athletes with greater muscle volume may have inferior objective sleep quality. This study aimed to assess the relationship between body composition and objective sleep parameters in male and female athletes. The body composition of 17 male and 19 female collegiate athletes were measured, and they underwent overnight home sleep monitoring. Compared with female athletes, male athletes had more muscle mass and less fat mass. Moreover, male athletes had lower sleep efficiency, longer sleep onset latency, higher arousal index, less rapid eye movement (REM) sleep, and lower percentage of slow-wave (N3) sleep in the initial non-REM sleep. Furthermore, the percentage of muscle mass was inversely related, whereas fat mass or percentage of fat mass was directly related to the percentage of N3 sleep in the initial non-REM sleep. Overall, there were no significant association between sex and sleep parameters. However, a significant correlation was found within both subgroups. Objective sleep quality was suggested to be worse in male athletes than in female athletes, implying that sleep architecture may be related to the muscle volume., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Study Objectives: Sleep is an important recovery period for athletes. Women, including athletes, have reported sleep disturbances around menses. Thus, the aim of this study was to assess the changes in objective sleep parameters in the nights during menses and in the midfollicular phase of the menstrual cycle of young female athletes., Methods: Female collegiate athletes with regular menstrual cycles were recruited. The participants underwent home electroencephalogram monitoring during the first and second nights after the onset of menses (M1 and M2, respectively) and during one night between the 7th and the 10th night after menses onset (midfollicular phase)., Results: Data from 45 athletes were analyzed. The total sleep time was significantly reduced, and sleep onset latency was significantly prolonged in M2 compared with those in the night during the midfollicular phase. Sleep efficiency was significantly reduced in M1 compared with that in the night during the midfollicular phase. Changes in the percentage of deep sleep across menstrual cycles differed among the participants with and without menstrual symptoms or concerns for sanitary products; moreover, such participants spent a lower percentage of time in deep sleep in M1 compared with the other nights., Conclusions: Collegiate female athletes with regular menstrual cycles are likely to have trouble falling asleep, tend to sleep less, and when concerned about sanitary products, have less deep sleep during menses. Even in young female athletes with regular menstrual cycles, sleep can be disturbed during menses. Interventions to restore or improve sleep should be considered., (© 2020 American Academy of Sleep Medicine.)

Background: Sleep is an important recovery period for athletes. In general, women are not satisfied with their sleep quality, which is also true for female soccer players, although the reasons remain to be elucidated. This study aimed to confirm sex difference in sleep quality among athletes from various fields of sport, and to investigate factors related to poor subjective sleep quality in male and female athletes., Methods: We collected data concerning subjective sleep quality, measured by Pittsburgh Sleep Quality Index (PSQI), from athletes who were 16 to 40 years of age and played various types of sports. Data concerning their sports, lifestyle, and sleep issues and sleep environments, and also menstrual issues for females, were collected., Results: Data from 207 male athletes and 215 female athletes were assessed. Among them, 31.4% of men and 48.8% of women had poor subjective sleep quality (i.e., PSQI≥6). In male athletes, witnessed apnea, episodes of disorientation or confusion during the time of sleep, long time gap between dinner and bedtime, and turning on the heating in the winter, were identified as factors associated with poor sleep quality by multivariate analysis, whereas in female athletes, bathing close to bedtime, habitual drinking, and being annoyed by noises at bedtime were identified., Conclusions: In both populations, females had poorer subjective sleep quality than males. Sex differences exist in factors associated with poor subjective sleep quality. Thus, different approaches should be considered to improve their sleep quality.

In this study, we aim to clarify the influence based on bone resorption markers at onset of stress fracture. Also, we will clarify the state of the bone resorption markers of female long distance runners who have a history of stress fracture and also ones who routinely practices running long distances. Participants comprised 19 female long distance athletes. The survey period was 2011-2014, and we measured u-NTX as a bone resorption marker at least twice a year, taking the mean±SD of the periodic measured values without stress fracture as the mean value. Measurements were collected sample when stress fractures developed. 132 u-NTX measurements were taken from 19 participants. As a result, the average was 41.03±12.31 nmolBCE/mmolCRE (Q1: 33.15, Q2: 40.55, Q3: 47.95). In six of the 19 participants, u-NTX could be measured following a stress fracture. The mean value of u-NTX for those participants was 40.16±9.10 nmolBCE/mmolCRE, increasing to 64.08±16.07 nmolBCE/mmol CRE with the stress fracture (p<0.01). The findings showed that, in adult female long distance runners, u-NTX values when there was no stress fracture were within the standard value for mean premenopausal women, but increased when the athletes suffered from a stress fracture., Competing Interests: Disclosure The authors report no conflicts of interest in this work., (© Georg Thieme Verlag KG Stuttgart · New York.)

Wheat gluten hydrolysate (WGH) is a food ingredient, prepared by partial enzymatic digestion of wheat gluten, which has been reported to suppress exercise-induced elevation of serum creatinine kinase (CK) activity. However, its effects on athletic performance have not yet been elucidated. This is the presentation of an experiment performed on five female college triathletes who completed an Olympic distance triathlon with or without ingestion of 21 g of WGH during the cycling leg. The experiment was performed in a crossover double-blind manner. The race time of the running leg and thus the total race time was significantly shorter when WGH was ingested. However, serum CK levels exhibited no apparent differences between the two WGH or placebo groups.

Wheat gluten hydrolysate (WGH) is reported to suppress the muscle injuries associated with exercise in long distance running and weight training. In the present study, we investigated the effects of WGH consumption on suppression of muscle injury after soccer training in a double-blind crossover study. Immediately after a mini soccer game, six soccer players consumed 18.0 g of WGH, and muscle injury was investigated using serum creatine kinase (CK) as an indicator. The results showed a significant increase in serum CK from immediately after exercise to 12 h after exercise stress (p<0.05) in the placebo group, while serum CK decreased during this same time period in the WGH group, and the difference between the two groups was significant. This suggests that WGH consumption suppresses delayed-onset muscle injury after exercise in soccer.

Wheat gluten hydrolysate (WGH) is rich in glutamyl residue; glutamine is considered a conditionally essential amino acid under physical stress. WGH has been reported to suppress post-exercise rises in serum creatine kinase in male distance runners. This study aimed to reproduce the effects in female distance runners under similar conditions. The study was conducted in a double-blinded crossover manner. Six female collegiate distance runners ingested WGH or a placebo after a 2-h run at an intensity estimated as 60-70% of their maximum oxygen uptake. Blood was sampled before, immediately after, and at 10 and 24 h after the run. Unlike those in male runners, serum creatine kinase (CK) increased slightly, with a peak at 10 h after the run, while plasma glutamine kept declining. The anti-inflammatory effect of WGH was not evident since the post-exercise elevation of CK was ambiguous. Plasma glutamine concentrations also showed a different kinetics from that in men.

Objective: We investigated the pattern of delayed-onset muscle injury in well-trained athletes after a competitive half-marathon and the effects of post-race intake of wheat gluten hydrolysate (WGH)., Methods: Thirty well-trained college runners with a best time of 14-15 min over 5000 m raced in a half-marathon. Thereafter, they were divided into three groups based on finish times and given 0 (control), 10, or 20 g of WGH. Blood biochemical parameters were monitored at -1 d, +1 h, +1 d, and +2 d after the race. Data selected according to finish times and biochemical parameters were then analyzed., Results: Plasma creatine kinase activity peaked at 1 d after the race in the control group and correlated with post-race white blood cell counts. The post-race elevation of creatine kinase activity was dose-dependently suppressed by WGH., Conclusion: Delayed-onset muscle injury peaked in well-trained distance runners at 1 d after a half-marathon and was dose-dependently suppressed by a post-race intake of WGH.

Athletes become increasingly susceptible to infection with intense training that results in immune suppression. The immune state was investigated after administering cystine/theanine (CT), which has been reported to have an immune reinforcement effect, to athletes before training involving a prolonged period of intense exercise. Fifteen long-distance runners were each allocated to the CT or placebo group, and the test food was ingested for 10 d prior to the start of training. Clinical examinations were performed before and after the training. The results indicate a significant increase in the high-sensitivity C-reactive protein (hs-CRP) and neutrophil count in the blood, as well as a decreasing tendency for lymphocytes in the placebo group, but not the CT group. These observations suggest that the ingestion of CT contributed to suppressing the change in inflammatory response, prevented a decrease in the immune function, and prevented infection and reduced symptoms when infected associated with continuous intense exercise.

This study investigated whether intake of lactoferrin (LF) would improve or prevent anemia in female long distance runners who were training during the summer season and had a high risk of iron-deficiency anemia. Sixteen female long distance runners were divided into a group taking LF and iron (the LF group) and a group that only took iron (the control group) for 8 weeks. In the control group, the ferritin, serum iron, and red blood cell count were significantly lower than before treatment. In the LF group, the hematology data showed no significant change during the 8 weeks. The red blood cell count was significantly higher in the LF group than in the control group. The blood lactate level following a 3,000-m pace run of the control group was also significantly higher than that of the LF group. These observations suggest the possibility that intake of LF increases the absorption and utilization of iron and would be useful in the prevention of iron deficiency anemia among female long distance runners.