The present study reviewed the current trends of interventions focused on the physical activity environment for reducing sedentary behavior among children. Multiple international and domestic databases were searched to identify studies that involved changes to the physical activity environment, measured sedentary behavior, were specific to childhood populations, and published in a peer-reviewed journal. After studies were carefully assessed for inclusion by examining the title, abstract, and full text, the characteristics of the included studies (i.e., participants, study design, environmental intervention, measurement of sedentary behavior, and results) were summarized. A total of 31 studies (randomized controlled trial: n=25; quasi-experimental design: n=3; within-subject design: n=3) met the inclusion criteria. The majority of studies (n=23) were conducted using school-based interventions focused on the playground environment, involving either one or a combination of the following changes: improved markings, providing play equipment, or offering built facilities. Other studies included in the summary focused on behaviors at home and in the community like using electronic time managers while watching the television and providing low-cost or free entry to safe and easily accessible sports facilities. The measurement of sedentary behavior included an accelerometer, self-report, and direct observation. Twenty studies had a positive effect on reducing sedentary behavior among children. All but two of the studies were conducted in foreign nations. The present findings suggest that improving the physical activity environment to children can reduce sedentary behavior; therefore, further interventions focused on the physical activity environment for reducing sedentary behavior among Japanese children should be conducted.
Energy balance plays an important role in weight control. Ghrelin is known to stimulate food intake, while peptide YY (PYY) and glucagon-like peptide (GLP-1) are known to suppress food intake. These appetite-related hormones are affected by behaviours such as exercise and mastication. Increasing the number of times food is chewed during a standard meal suppresses ghrelin secretion and food intake. The intensity of exercise is more strongly related to the secretion of total ghrelin, acylated ghrelin, PYY3-36 and food intake than the duration or mode of exercise. This review summarises the effects of exercise and mastication on appetite-related hormones and/or energy intake.
A number of studies have been conducted to examine the influence of physical activity on psychological well-being in young people; however, few studies have discussed the relationship between exercise and mental health. The purpose of this article was to investigate the influence of exercise on mental health in adolescents by performing a brief review. Although the studies included in this review are cross-sectional, relatively small scale and lack measurement consistency, the results show that participating in exercise and/or sports is likely to significantly improve mood. Organized sport activities contribute to the reduction of chronic stress response. On the other hand, higher levels of sedentary behavior are associated with worse mental health. These findings suggest that physical activity may enhance psychological well-being, and chronic vigorous exercise and sport activities are effective in promoting improvement of mental health in adolescents.
Understanding factors associated with physical activity (PA) is important to promote PA. The purpose of the present study was to investigate factors associated with achieving PA guideline in 293 Japanese adolescents (140 boys and 153 girls). Time spent in moderate to vigorous PA (MVPA) was accessed by using accelerometers. Based on MVPA, the participants were classified as “Active” (≥60 min/day of MVPA) or “Inactive” (<60 min/day of MVPA). Anthropometry, age, screen time, mental health, participation in after-school sport activities, sleep status, and breakfast status were measured as factors potentially associated with achieving PA guideline. Adjusted logistic regression analyses revealed that after-school sports activities were positively associated with the probability of being Active for both sexes (odds ratios [ORs] [95% confidence intervals (CI)] = 3.90 [1.13-13.49] for boys, 4.80 [1.80-12.81] for girls). In addition, body fat was negatively associated with a reduced likelihood of being Active for girls (ORs [95%CI] = 0.93 [0.87-0.97]). Two factor ANOVA revealed that those in Inactive group had significantly lower PA levels than those in Active group on both regular curriculum and extra-curriculum (F (1, 138) = 152.50 for boys, F (1, 151) = 181.95 for girls, p < 0.001). In addition, for girls, there was a significant interaction effect between domain (regular curriculum vs. extra-curriculum) and after-school sport activities (F (1, 151) = 4.91, p = 0.028), suggesting that obtaining higher PA levels on extra-curriculum might be difficult for those who do not belong to any after-school sport activities. Therefore, promoting PA on regular curriculum (i.e., physical education lessons and recess) might be alternative ways to increase PA levels for those individuals. Furthermore, special attention may be needed for girls who have higher body fat to promote PA.
Taping is widely used in sports medicine to prevent injury, protect affected sites post injury and relieve pain. However, it is not clear whether taping affects the perception of noxious stimulation because in previous studies, it was difficult to selectively activate Aδ fibers. A recently developed, useful, new tool named intra-epidermal electrical stimulation (IES) can preferentially activate Aδ fibers. We aimed to clarify the effect of taping on pain-related somatosensory evoked potentials (pSEPs) using IES. We recorded pSEPs following IES of the right medial forearm in twelve healthy volunteers. pSEPs were recorded from 9 electrodes on the scalp under control, elastic-taping and white-taping conditions. Under the control condition, subjects relaxed on a comfortable reclining seat without taping, whereas under the taping conditions, they were subjected to taping along the forearm with tension (elastic-taping) and without tension (white-taping). Subjects were asked to assign a visual analog scale (VAS) score after each session. The peak amplitudes of N2-P2 were significantly lower under the elastic-taping and white-taping conditions than those under the control condition. VAS was significantly lower elastic-taping condition than those under the control and white-taping conditions. Moreover, there was a significant positive correlation between the amplitude of N2-P2 and VAS. We revealed that taping along the forearm decreased pSEPs and subjective pain perception under the white-taping and elastic-taping conditions. The underlying mechanism of pain relief was the distraction effect in both taping conditions. In addition, elastic-taping with tension changes afferent inputs mainly from the skin, and this might more effectively decrease the subjective pain perception than that achieved under the white-taping condition.
This study aimed to assess the effect of short-interval intracortical inhibition (SICI) before a jump off a platform (pre-set) on drop jump (DJ); the purpose was to investigate the relationship between this activity and performance, and the different effects of SICI on agonist and antagonist muscles during pre-set for jump athletes. Jump athletes (Jumper group, n=13) and Other athletes (Other group, n=9) performed DJ from drop heights of 0.30, 0.45, and 0.60 m). DJ performance was evaluated with DJ-index which was calculated from contact time and jump height. SICI was calculated from motor evoked potentials (MEP) recorded using paired-pulse transcranial magnetic stimulation for the medial gastrocnemius (MG) and tibialis anterior (TA) muscles in 7 jump athletes. Significantly higher DJ performance was observed for the Jumper group at all drop heights, and the Jumper group exhibited greater performance for the highest drop height than the Other groups. Significant decreases in SICI for MG were observed for the Jumper groups, and this decrease in inhibition was more prominent for the highest drop height during pre-set. Furthermore, the correlation between SICI for MG and DJ-index was stronger for increased drop heights, and a significantly positive correlation between these variables was observed at a height of 0.60 m. However, the SICI during the pre-set for TA exhibited no significant change under any of the conditions. The results of the present study suggest the importance of selective disinhibition of brain areas associated with the agonistic muscles during pre-set for higher DJ performance.
Dynamic postural control ability is necessary for fall prevention in our daily lives. It has been suggested that dynamic postural control ability is highly related to the muscles in the trunk as well as the lower limbs for the keep and move of the body. In this study, we reveal relationship between dynamic postural control ability and abdominal area. Subjects including 31 middle-aged people consist of 12 men and 19 women (mean age 60.0±7.6 years). We measured visceral fat area and cross-sectional area of the trunk muscle using abdominal computed tomography scan. The unstable tilt board is used for measuring dynamic postural control ability. Through multiple regression analysis, it is possible to relate dynamic postural control ability from gender, visceral fat, and deep trunk muscle such as psoas major muscle on abdominal computed tomography scan. It is considered that dynamic postural control ability involved not only increasing the volume of deep trunk muscle but also decreasing the amount of visceral fat.
The aim of the present study was to investigate the consciousness among young people (n = 494) of training body part(s) by showing participants a picture of an exercise, through a questionnaire-based survey. Participants were shown a picture of a Back Squat, and were asked which body part(s) they felt was being trained in the picture. Participants who had no experience of doing squatting exercises (NO-SQUAT group, n = 102) and participants who were experienced in terms of doing squatting exercises and weight training under appropriate supervision (INSTRUCTED group, n = 146) were selected for the analysis. On seeing the picture, more than half of the NO-SQUAT group felt that the Back Squat was to train not only their lower body but also another body part(s); among these participants, approximately 70% felt that a Back Squat was appropriate to train their upper torso and arms too. Further, the NO-SQUAT group had made significantly fewer attempts to consciously train their gluteal and knee flexor muscles, and had made significantly more attempts to consciously train their upper torso and arms during the squatting exercises than the INSTRUCTED group had. These results suggest that to do exercises by referring to only a picture may result in the participants not properly understanding how the body part(s) should be trained during exercise. Therefore, to enhance the benefits of training, individuals need to be instructed, under appropriate supervision, on correct technique as well as knowledge about the exercise.
The purpose of the present study was to indicate the relationship between health-related quality of life (HRQOL) measures, the daily rhythm of oral temperature (OT), and lifestyle. Five-hundred young men volunteered to participate in this study. Their OT, measured using a digital thermometer, was recorded every 2h from the time they woke up to the time they went to sleep for 1 week. The daily rhythm of OT was calculated as a quadratic function using the 1-week data. The HRQOL was measured using the Short-Form 36-Item Health Survey version 2 (SF-36v2). The participants were divided into 3 groups: a high-value group (HG) with ≥ 55 points of each summary score and each subscale score, a middle-value group (MG) with score > 45 and < 55 points, and a low-value group (LG) with score ≤ 45 points. Lifestyle was assessed in terms of eating habits, sleeping and exercise, and the presence of unidentified complaints. At the mental component summary, the OT at the time of waking up and the peak OT in the HG were significantly higher than those in the LG. At the physical and mental component summary, lifestyle in the HG was more favorable. These data suggest that the daily rhythms of OT may reflect the mental health status of an individual. The entraining factors in circadian variation might play a role in improving mental health and reducing unidentified complaints. In conclusion, there appears to be an association between mental health status, lifestyle, and daily rhythms of OT.