The effects of exercise on sleep have been explored from various perspectives, but little is known about how the effects of acute exercise on sleep are produced through physiological functions.We used a protocol of multiple daytime sessions of moderate-intensity aerobic exerciseand examined the subsequenteffects on sleep structure, core body temperature, distal-proximal skin temperature gradient, and subjective parameters. Fourteen healthy men who did not exercise regularly were evaluated under the baseline (no exercise) and exercise conditions on a within-subject crossover basis. Under the exercise condition, each participant performed a 40-min aerobic workout at 40% of maximal oxygen intakefour times between morning and early evening. We observed a 33% increase in slow-wave sleep (p=0.005), as well as increases in slow-wave activity (p=0.026), the fast-sigma power/slow-wave activity ratio (p=0.005), and subjective sleep depth and restorativeness the following morning. Moreover, both core body temperature and the distal-proximal skin temperature gradient increased during sleep after exercise (p=0.021 and p=0.047, respectively). Regression analysis identified increased nocturnal distal-proximal skin temperature gradient during sleep after exercise as a factor in the increase in slow-wave activity. The fast-sigma/ slow-wave activity ratio correlated with core body temperature. Performing acute exercise promotes slow-wave sleep with nocturnal elevation in the distal-proximal skin temperature gradient. Both core body temperature and fast-sigma power may play a role in the specific physiological status of the body after exercise.

This study examined the effects of prophylactic naps on physical fitness/exercise ability and executive function. Seven healthy trained males (mean age, 21.1 ± 0.4 years) participated in four experimental conditions (counterbalanced design): 90-min sitting rest (con condition); 30-min nap (nap30 condition); 60-min nap (nap60 condition); and 90-min nap (nap90 condition). Physical fitness/exercise abilities were assessed by grip/back strength, postural control, darts task, and the Wingate test. Executive function was assessed using simple reaction time (SRT), choice reaction time (CRT), and modified flanker tasks. Changes in oxyhemoglobin levels in the prefrontal cortex during the executive function tasks were monitored using near-infrared spectroscopy. None of the nap conditions (30, 60, 90-min) showed improvement in physical fitness/exercise abilities compared with the con condition. The nap30 condition showed shorter reaction times (RTs) in the SRT and CRT tasks than the con condition. The nap60 condition showed improved RTs in only the SRT task. The nap90 condition showed improved RTs in all executive function tasks. Increased oxyhemoglobin levels in the nap30 and 90 conditions were matched with improvement of each executive function tasks, but not in the nap60 condition. In conclusion, 90-min nap augmented the improvement of executive function tasks and activating the prefrontal cortex.

Biologics have dramatically changed breast cancer treatment, and trastuzumab has been an essential treatment drug for HER2-positive breast cancer. The introduction of trastuzumab biosimilar offers the potential to deliver long-term cost savings plus efficiencies for healthcare systems in Japan. The goal of biosimilar development is to demonstrate comparability to the original biologic with a different development concept from that of the original biologic. Hence, a better understanding of the biosimilar itself is urgently needed for appropriate adoption and the integration of trastuzumab biosimilars into oncology clinical practice by all stakeholders. This article focuses on the current situation of biosimilars and future perspectives in Japan by using the trastuzumab biosimilar as an example.

It has been noted that Japanese children sleep the least in the world, and this has become a major social issue. This study examined the pathways linked to sleep habits (SH) among children and adolescents. A questionnaire-based survey was conducted in March 2019 on children and their parents at all 63 public elementary and 29 public junior high schools in Setagaya-ku, Tokyo. For the analysis, 22,385 pairs of children–parent responses (valid response rate: 68.8%) with no missing data were used. This survey collected data on SH, physical activity (PA), screen time (ST) for the child, and lifestyle and neighborhood social capital (NSC) for the parents. Moreover, the pathways linking ‘NSC’ → ‘parental lifestyle’ → ‘child’s PA/ST’ →‘child’s SH’ were examined through structural equation modeling. The results indicated that children’s SH were affected by their PA and ST and influenced by the lifestyle of their parents and the NSC that surrounds them. Thus, we concluded that it is necessary to provide direct interventions and take additional measures with regard to parent lifestyle and their NSC to solve persistent sleep problems in children.

This study examined changes in physical activity (PA), sedentary behavior (SB), screen time, sleep, and executive function among Japanese preschoolers between COVID-19 pre-pandemic and pandemic periods, using cross-sectional and longitudinal data. Accelerometer data from 63 children aged 5–6 years were collected from three kindergartens in Tokyo, Japan, in late 2019 (pre-COVID-19). This was compared to the data of 49 children aged 5–6 years from the same kindergartens, collected in late 2020 (during COVID-19). Sixteen children in the pre-COVID-19 cohort also participated in the 2020 survey and provided data for the longitudinal analysis. The mean minutes of PA, SB, screen time, and sleep duration, as well as executive function, were compared between the pre- and during COVID-19 cohorts. After adjusting for school, sex, and accelerometer wear time, there were no significant differences in any of the measured outcomes between the two cohorts. However, the analysis of longitudinal data revealed significant increases in time spent in SB and on screens, and a decrease in light-intensity PA and sleep duration during the pandemic compared to the pre-pandemic period. Results suggest that, despite the COVID-19 pandemic, young children’s activity levels and SB did not significantly differ from pre-pandemic levels. However, school-aged children’s SB, light PA, and sleep time were affected, although this cannot be disentangled from the effects of the transition to school.

Sleep problems are especially serious in Japan. The purpose of the present study was to clarify the effects of a shift of residence to a mountain village on children’s melatonin responses. The participants were 19 children (nine males and ten females, 10–15 years old) who participated in the Mountain Village Educational Program. After excluding a girl with confirmed deficits, the data of 18 participants were used for analysis. We measured salivary melatonin concentration and assessed the self-completed questionnaire survey on sleep situation. Although the proportion of people who showed a greater salivary melatonin concentration at night than in the morning immediately after starting the Mountain Village Educational Program was 50%, after that it was shown that melatonin concentration increased at night and decreased in the morning. The results demonstrated that all participants showed a salivary melatonin secretion pattern of night > morning after approximately 3.5 months. Based on these findings, the Mountain Village Educational Program, which involves a shift of residence to a mountain village, has the potential to improve children’s sleep. Abbreviations: DLMO: Dim light melatonin onset; MVEP: Mountain Village Educational Program