The purpose of the present study was to determine effect of wearing compression garments （CG） with different pressure level on muscle oxygenation, glucose metabolism and exercise performance during prolonged pedaling. Ten triathletes （19.9±1.2 years, 172.2±4.4 cm, 62.0±3.8 kg，BMI; 20.9±0.7 kgm^-2; ･VO_2max; 59.3±4.4 mlkg^-1min^-1） completed three trials on different days, consisting of ^1） exercise with wearing CG which exerted high pressure on the thigh （approximately 40 hPa, HIGH） ^2）， exercise with wearing CG which exerted moderate pressure on the thigh （approximately 20 hPa, MED） ^3）， exercise with normal sport garments which exerted low pressure on the thigh （below 10 hPa, CON）．Each trial was performed with randomized orders, and four weeks of washout period were provided between the trials. The exercise consisted 90 min of pedaling at 65% of maximal oxygen uptake （･VO_2max）．Time-courses of changes in heart rate （HR），ratings of perceived exertion （RPE）， oxy-hemoglobin, exogenous glucose utilization （¹³C glucose） and respiratory variables were evaluated during 90 min of pedaling. After completing 90 min of pedaling, time to exhaustion （TTE） test was conducted at 85% of ･VO_2max.

Exercise rapidly increased ¹³C excretion, but highest value of ¹³C excretion was shown earlier in the MED trial （47.1±9.9 min） compared with in the other trials （HIGH trial; 67.3±23.7 min, CON trial; 53.95±9.5 min, P<0.05）．No significant difference was observed for changes in other variables and TTE among the trials. In conclusion, wearing CG which exerted 20 hPa on the thigh facilitated exogenous glucose utilization during 90 min of pedaling.

The pattern of the official ball used in the 2006 FIFA World Cup is considerably different from that of a conventional soccer ball （having 32 pentagonal and hexagonal panels）. Depending on the number of different panels and their orientation, the aerodynamic force experienced by a ball is believed to change, which in turn changes the ball trajectory. However, not much is known about the impact of the surface forms of a ball on its aerodynamics. Therefore, in the present study, 5 different types of soccer balls were produced and their aerodynamic properties were studied by wind tunnel experiments. The results confirmed that the aerodynamic force acting on the ball varied considerably depending on the surface form of the balls. Thus, the fact that the aerodynamic force acting on the ball varies depending on the surface form of the soccer ball suggests that surface roughness is also one of the important factors that determine the aerodynamic characteristics of the ball in addition to the shape and number of panels.

The purpose of this study was to examine the effects of several levels of pressure applied to the knee during standing and low intensity exercise on lower leg swelling volume and sensation. In experiment A, eight healthy women standing upright had cuff pressure applied to their knees at 10, 20, 30, and 40 mmHg or without cuff for 20 minutes. The swelling volume and sensation were measured at the beginning and the end of the standing session. In experiment B, nine healthy women in a standing position had cuff pressure applied to their knees at 20 and 40 mmHg or without cuff during 20 minutes of step exercise. The cuff was removed immediately after that and the women remained standing for 20 minutes. As a result, leg and foot volume at the end of the standing session were significantly greater after 40 mmHg pressure compared with the other conditions in both experiments A and B. In experiments A, the swelling sensation was not significantly different between conditions. In experiment B, the swelling sensation at the end of the standing session under 40 mmHg pressure was significantly lower compared with 20 mmHg （P<0.05）, but not compared with the no cuff condition. The lower leg and foot volume and swelling sensation under the no cuff condition tended to increase at the end compared with baseline in both experiments A and B. These results suggested that a pressure of less than 40 mmHg on the knees during standing and step exercise can help prevent lower leg and foot swelling.

We attempted to develop novel and comfort leisure winter sports wear such as ski wear or snow board wear that could enjoy going for the winter sports in the coldest part of the winter. This novel and comfort leisure winter sports wear was equipped with textile fabric heater which was plain stitch fabric formed by polyamide 66 filament coated silver and polyethylene terephthalate yarn. We have examined about the electric resistance change of textile fabric heater under tensile strain until breaking point and the electric resistance change in case of applying concentrated compression load on textile fabric heater. Experiments were carried out to evaluate heating performance of textile fabric heater under a below-zero temperature and low temperature conditions. And, we designed prototype for comfort leisure ski wear. Experiments using prototype ski wear under a below-zero temperature confirmed that the temperatures in wear obtained from both cloth and pants indicated appropriate condition. It was also confirmed that the equipment method of textile fabric heater and attached points for human body was a rational procedure from experimental results. In this winter season, we make a plan practical test using ski wear equipped with textile fabric heater by examinees including to the persons of advanced age from elementary school children.

We are going to complete comfort leisure winter sports wear equipped with textile fabric heater consulting examinees about the problem and/or improvement points.

The ischemic preconditioning phenomenon was introduced in a study that demonstrated that repetitions of short-term ischemia and reperfusion of coronary arteries could reduce the myocardial damage following prolonged ischemia （direct effect）．Moreover, it was later demonstrated that the ischemic preconditioning of coronary arteries also protects remote cardiac tissue that is not directly exposed to ischemic preconditioning （remote effect）．Because of the intermittent nature of the blood flow during intense muscle actions, it was proposed that ischemic preconditioning prior to exercise could increase muscular performance. Although most of the exercise studies employed an ischemic preconditioning protocol involving four cycles of 5-min circulatory occlusion followed by a 5-min reperfusion period, the optimal number of repetitions of ischemic preconditioning remained unclear. First, we examined the effective repetition numbers （from one to four） of direct and remote ischemic preconditioning in lower leg on exercise performance and fatigability. Contrary to previous reports, the results showed that any repetition of ischemic preconditioning did not affect the maximum strength and fatigability in knee extension. Concerning those negative results, we examined effects of ischemic preconditioning in a practical exercise of repeated-jump and combined ischemic preconditioning with dietary nitrate （donor of nitric oxide）．However, we could not demonstrate significant effects of ischemic preconditioning on exercise performance and muscle damage even with dietary nitrate.

In the present study, we investigated the effects of aerobic exercise under dehydrated and euhydrated conditions on human cognitive processing. Fifteen healthy males performed 4 × 15-min bouts of cycling exercise, and event-related potentials （ERPs） were recorded in three sessions during somatosensory Go/No-go paradigms （Pre- and Post exercise and Recovery）．As thermoregulatory and hemodynamic variables and blood tests, the esophageal temperature, mean skin temperature, heart rate, mean arterial blood pressure, plasma osmolality, hematocrit, and hemoglobin were recorded. The reaction time was earlier at Post than Pre under dehydrated and euhydrated conditions. The peak amplitude of the N140 component, which was mainly related to somatosensory processing, was significantly reduced at Post and Recovery than at Pre under dehydrated conditions, but not under euhydrated conditions. The peak amplitude of the P300 component, which was linked to the cognitive processes of context updating, context closure, and event-categorization, was not affected by aerobic exercise under dehydrated or euhydrated conditions. These results suggest that aerobic exercise under dehydrated conditions affects neural activity for somatosensory processing, while the executive function, which was based on reaction times and error rates, and higher cognitive processing reflected by P300 would not be affected by aerobic exercise under dehydrated or euhydrated conditions.

It is important to maintain the skeletal muscle mass for extending healthy life expectancy. Recently, myokine which is released from skeletal muscle by muscle contraction has been paid attention for maintain of muscle mass. Many studies suggested that the myokoines are facilitated by high-volume exercise. The purpose of the present study was to verify that myokines, involved in maintain of muscle mass, are enhanced by low-intensity exercise under cold environment. Six healthy males （Age: 22.4 ± 0.4 yrs, height: 171±2.7 cm, weight: 63.8±2.8 kg） conducted exercise with a normal temperature condition （n = 6） and exercise with a cold temperature condition （n = 6）．All subjects performed pedaling at 60% of maximal oxygen uptake （V･O₂max） for 60 min in each condition. Blood samples were collected before exercise, during exercise, immediately after exercise, and 1, 3, and 24 h after exercise.Unanticipatedly, Irisin and FGF21 concentrations in blood did not show significant difference between groups. However, decreased blood insulin concentration was impaired in cold temperature condition, but not normal temperature condition.Therefore, these results suggested that exercise with cold environment did not effective for myokines, involved in maintain muscle mass response to exercise.

It is known that muscle relaxation of one muscle induces temporal reduction in force level of the other muscle. Furthermore, many previous study investigated that transcranial direct current stimulation （tDCS） induced increase in training efficiency for motor learning.In the present study, we investigated the effect of tDCS on the primary motor cortex during 3 days’ training including muscle relaxation. Thirty healthy participants were divided into 3 groups （without stimulation, with anodal stimulation and with cathodal stimulation）， and they sustained isometric contraction of their right finger. Then participants simultaneously performed muscle relaxation of shoulder adduction immediately after audio cue from 50% MVC of isometric contraction for 30 times in each day. Participants performed the task for three days with 2 -10 days interval. As a result, sustained force level of finger contraction was temporally decreased by muscle relaxation of shoulder. However, changes in its effect due to the 3 days&apos; training without stimulation was not observed. Likewise, no changes in its effect were observed in both anodal and cathodal groups. Present study revealed that different mechanism might be involved in motor learning process for muscle relaxation compared to that of muscle contraction.

Ski jumping competition is a sport that competes in term of the total point of "Distance Point" that digitizes the flight distance and "Judges Point" that digitizes the beauty of flight attitude and landing, and ski jumpers attempt to fly as far as possible. In competition, there are many regulations to ensure fairness. In the international ski jumping competition rules, suit fabric must show the air permeability of a minimum of 40 liters per m2/sec under 10 mm water pressure. However, the effect of air permeability of suit fabric on aerodynamic characteristics has not been completely clarified yet. The purpose of this study is to investigate the effect of air permeability of suit fabric on aerodynamic characteristics. Four types of fabric with different air permeability are used and the wind tunnel experiments were carried out using the fabric clothed elliptic cylinder. The drag coefficient decreases with increasing the air permeability. Also, the stall delay occurs for the fabric with high air permeability, and the lift to drag ratio at the high angle of attack can be improved. Furthermore, it was confirmed that the velocity profiles near the surface show the different tendency for different air permeability fabric. It is presumed that the aerodynamic performance of ski jumpers during a flight can be improved by depending on the air permeability of the ski jumping suits fabric. The flight distance for each fabric was calculated with the aerodynamic force data assuming that the elliptic cylinder flies. Case-2 with increased air permeability have longer flight distances than Case-1 （original air permeability）．

In the human body, electric resistance varies depending on the temperature of the muscle tissue. In the present study, the effect of cooling on electric resistance was investigated using multi-frequency impedance device while cooling the aorta in the popliteal region in addition to local cooling from the skin surface of the triceps surae. Subjects were ten healthy male students （age: 21.1±1.5 years） of our university. Impedance was measured by the tetrapolar impedance method using a multi-frequency impedance device （MFBIA-07, Tanita） with a frequency at 50 kHz, 100 kHz and 250 kHz. The current （I） electrodes and the sensing （V） electrodes were attached longitudinally to the calf. In order to measure impedance, the distance between the two sensing （V） electrodes were placed at a distance of 15cm. The current electrodes were set at 2cm, 3cm, and 4cm from the V electrode on the distal side. Measurements were obtained following either cooling of the sural region only or cooling of the sural and the popliteal region. During cooling, impedance and skin temperature were measured every 5 minutes for 30 minutes. Temperature was measured at 2cm, 3cm, and 4cm depths from the skin surface of the triceps surae. Under both cooling conditions, a decrease in temperature was observed over time. In addition, the changes in cooling temperature decreased with increase in depth from the skin surface. The effect of cooling was greater while cooling the aorta in the popliteal region than while cooling the sural region only. Therefore, the cooling effect could be enhanced by cooling the aorta on the central side with simultaneous local cooling.

Reactive oxygen species （ROS） production during exercise is thought to be related to an improvement in cognitive function. We hypothesized that high intensity interval exercise induced ROS production is lower compared with continuous high intensity exercise. Also, high intensity interval exercise contributes to improvement in cognitive function because of lower ROS production. In this experiment, in order to verify this hypothesis, we examined the influence of different exercise mode on ROS production. Continuous high intensity and high intensity interval exercise were performed, and the thiobarbituric acid reaction product （TBARS） value in plasma before and after each exercise was calculated as an index of ROS production. TBARS value increased significantly immediately after continuous exercise, while TBARS value tended to slightly increase after interval exercise, but significant difference was not observed. In the present study, the validity of the hypothesis was proved by showing that the difference in exercise mode shows that ROS production is different despite a similar work exercise. This finding suggests that there is the physiological advantages in interval exercise as a therapy for preventing dementia.

In recent years, sports vision has often been included in visual function training for preserving and restoring human cognitive functions. By taking the primary aspects of brain science and cognitive psychology into consideration, sports vision can be effective in maintaining cognitive functions. Furthermore, preventive measures against dementia need to be established for elderly people. In the proposed study, game content based on virtual reality was developed for diagnosing and managing mild cognitive impairment. A total of 164 paid healthy volunteers participated in the proposed study. Electroencephalogram （EEG） on the brow was performed while conducting the proposed game for sports vision training （SVT）．The obtained statistical results of the theta component in the EEG power spectrum demonstrate that cognitive activity can be enhanced through SVT.

The purpose of this study was to clarify the blood pressure （BP） and physiological response during mountain climbing and stay in high altitude. Six healthy adults climbed Mt. Fuji with measuring blood pressure by multi-sensor ambulatory blood pressure monitoring device. Pulse oximetry was performed during sleep in the research station at the summit of Mt. Fuji. BP during mountain climbing was higher than BP in daily life （24-hour systolic BP: 117.8±5.4 mmHg vs 111.4±5.8 mmHg, p=0.04. awake systolic BP: 123.4±6.9 mmHg vs 115.2±7.2 mmHg, p=0.03）．Awake systolic BP during mountain climbing was correlated with physical activity （R=0.87, p<0.05）．In addition, one subject with acute mountain sickness （AMS） showed abnormal circadian BP rhythm. The present study showed that BP during mountain climbing was associated with physical activity, and abnormal circadian BP rhythm may occur in AMS. We should pay attention with BP elevation and abnormal circadian BP rhythm during mountain climbing in high altitude.

The purpose of this study was to investigate the effects of gastric inhibitory polypeptide （GIP）， so-called glucose-dependent insulinotropic polypeptide, and glucagon-like peptide-1 （GLP-1） receptor agonist exendin-4 （Ex4） on mouse myoblast-derived cell line C2C12. Muscle protein content in C2C12 myotubes was increased by 10-8 M GIP （p<0.05）．On the other hand, Ex4 （10-8 and 10-6 M） had no impact on muscle protein content of C2C12 myotubes. GIP-associated increase of muscle protein content in C2C12 myotubes was observed in GIP-receptor-knockdown cells. However, GIP-associated effects on C2C12 myotubes was partially attenuated by knockdown of GIP receptor. GIP receptor knockdown itself has a stimulating effect on proliferative potential of C2C12 myoblasts. Evidences from this study strongly suggest that digestive hormone GIP may increase or maintain skeletal muscle mass. Oral food intake-associated digestive hormone（s）may be a potential tool for skeletal muscle hypertrophy.

Purpose: To investigate whether exercise training improves endothelial function.Methods: The present study included community-dwelling elderly individuals who were 65 years of age or older. The study participants were divided into the intervention group and the control group. The intervention group underwent the exercise program “interval walking training” during 5 months. Those who completed the assessments before and after the intervention period and did not have missing data were included in the analysis. The reactive hyperemia index （RHI） was used to evaluate endothelial function.Results: Forty-four males （19 from the intervention group） and 44 females （17 from the intervention group） were analyzed. At the baseline assessment, the RHI was 1.88±0.58 for males and 1.96 ± 0.73 for females. Among males, the RHI significantly increased in the intervention group, while the RHI did not significantly change in the control group. Among females, the RHI did not significantly change during the period either in the intervention or control group. Among males, the percent change of RHI was 25.4 ± 40.0% in the intervention group and 7.1 ± 37.7% in the control group （p = 0.127）．Among females, the percent change of RHI was 22.6 ± 54.6% in the intervention group and 19.0 ± 47.0% in the control group （p = 0.971）．After adjusting for age and hypertension, the percent change of RHI tended to be higher in the male intervention groups than in the control groups （p = 0.096 for males and p = 0.567 for females）．Conclusion: Interval walking training during 5 months would improve endothelial function among community-dwelling elderly males.

Physical performance is enhanced by counter movement. This phenomenon is called stretch-shortening cycle effect （SSC effect）．Recently, elasticity of attached cross bridges and residual force enhancement （RFE） have been suggested as possible mechanisms. This study examined the contribution of these factors by comparing the SSC effect attained in fast and slow twitch fibers. Rabbit psoas （fast） and soleus （slow） were harvested, and single muscle fibers were isolated. In the SSC trial, fibers were isometrically activated at an average sarcomere length of 2.4 μm, and stretched to 3.0 μm within 2 seconds. Immediately after the end of stretch, the fibers were shortened to 2.4 μm within 2 seconds. In the control trial, fibers were isometrically activated at an average sarcomere length of 3.0 μm, and shortened to 2.4 μm in 2 seconds. Mechanical work attained during the shortening phase was calculated, and relative increase in mechanical work between SSC and control trials was adopted as the index for the SSC effect. In addition, RFE and control trials were conducted. In the RFE trial, the fibers were isometrically activated at an average sarcomere length of 2.4 μm, and then stretched to 3.0 μm within 2 seconds. After the end of stretch, fiber length was kept constant for 15 seconds. In the control trial, fibers were isometrically activated at an average sarcomere length of 3.0 μm. This state was maintained for 15 seconds. The isometric force of the RFE and control trials 15 seconds after the end of stretch was compared to confirm whether RFE was induced. SSC effect was significantly larger in the soleus than in the psoas, but the magnitude of RFE was not different between the muscles. These results suggest that the observed difference in the SSC effect between the muscles was not caused by RFE, but by the elasticity of the attached cross bridges.

This study examined high-intensity intermittent training （HIIT） as an anti-obesity and anti-diabetes measure, and its effect on brown adipose tissue （BAT） activity.The study divided 8-week-old male C57BL/6J mice into a high-fat diet group （HFD; n = 8） and a high-fat diet plus HIIT group （HFD + HIIT; n = 8）．HIIT comprised 15 sets of swimming for 20 s, with a 10-s pause between sets, under 16% loading, 4 times per week, for 8 weeks. After 8 weeks of intervention, maximum number of HIIT until exhaustion, citrate synthesis （CS）， body weight, individual tissue weight, blood tests （total cholesterol [TC], low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C], glucose, and adiponectin）， and uncoupling protein 1 （UCP-1） expression in BAT were measured.Compared to the HFD group, the HFD + HIIT group had significantly higher maximum number of HIIT until exhaustion, CS activity, and adiponectin, with lower body weight, fat weight, TC, LDL-C, and blood glucose （P < 0.05）．Although UCP-1 expression in the HFD + HIIT group tended to be greater than in the HFD group （P = 0.09）， there was no significant difference between the two groups.The results suggested that HIIT may be effective in preventing lifestyle-related diseases. Further study of BAT activation with exercise is required.

ABSTRACT

【Background】The benefit of body weight resistance exercise with slow movement （BWRE-slow） for muscle function is well-documented, but not for energy metabolism. We aimed to examine physiological responses （e.g., energy expenditure （EE）， respiratory exchange ratio （RER）， and blood lactate （La）） during and after BWRE-slow compared with EE-matched treadmill walking （TW）．

【Methods】Eight healthy young men （23.4±1.8years old, 171.2±6.2cm, 63.0±4.8kg） performed Squat, Push-up, Lunge, Heel-raise, Hip-lift, and Crunch exercises with BWRE-slow modality: Both the concentric and eccentric phase were set to 3sec. A total of 3 sets （10repetitions） with 30 sec rest between sets were performed for each exercise （26.5min）．On another day, subjects walked on a treadmill for 26.5min during which EE during exercise was matched to that of BWRE-slow with the researcher controlling the treadmill speed manually.

【Results】The time course changes of EE and RER were measured. The EE during exercise for BWRE-slow （92.6±16.0 kcal for 26.5min） was not significantly different from the EE during exercise for TW （95.5±14.1kcal, P=0.36）．BWRE-slow elicited greater recovery EE （40.55±3.88kcal for 30-min） than TW （37.61±3.19kcal, P=0.029）．RER was significantly higher in BWRE-slow during and 0-5min after exercise, but became significantly lower during 25-30min after exercise, suggesting greater lipid oxidation was induced about 30-min after exercise in BWRE-slow compared with TW.【Conclusion】We also indicated BWRE-slow has 3.1METs in average which is categorized into moderate-intensity physical activity.

We have recently developed a comprehensive approach for monitoring leg swelling using several advanced technologies. With this approach, the present study aimed to investigate the exercise-induced leg swelling and its recovery in humans. The effect of wearing a compression stocking on leg swelling and muscle fatigue was also investigated. Healthy young volunteers performed unilateral calf-raise exercise for both legs, wearing a compression stocking only on one leg. Before and immediately after the exercise, maximum calf circumference was determined by tape measure, extracellular fluid resistance （R0） of the lower leg by segmental bioelectrical impedance spectroscopy, foot and lower leg volume by modified water displacement volumetry, and the gastrocnemius muscle stiffness by ultrasound shear-wave elastography. Concurrently, muscle soreness, contractile force during voluntary and evoked contractions, and unilateral vertical jump performance were examined. These measurements were repeated 1, 2 and 5 days after the exercise. There were significant increases in calf circumference, the reciprocal of R0 （an index of extracellular fluid volume）， and total lower leg volume immediately after the exercise. However, further measurements suggest that the exercise-induced leg swelling found in this study was mainly due to the increase in blood flow and metabolite accumulation, not due to muscle damage and subsequent inflammatory response. We also found a limited impact of sports compression stocking on the exercise-induced leg swelling, while the decrease in maximal voluntary contractile force tended to be attenuated in the leg wearing the stocking. These results suggest that wearing compression stockings accelerates force recovery during the first few days after exercise, which may not be related to its edema-preventing effect.

This study proposed a new model of muscle fatigue and recovery considering the role of slow and fast twitch muscles. This model can estimate the variation of the muscle fatigue since this model considers the properties of muscle fatigue and recovery, which the previous model does not consider. The feature of this study is to estimate not only the variation of muscle fatigue under maximum voluntary construction （MVC） but also the endurance time under any constant force. In order to validate the proposed model, a case study was conducted. The parameters, which depend on the human property, were determined by the measured variation under output of MVC. The endurance time under any constant force was also measured by the case study and the measured time was compared with the time estimated by the proposed model. According to the case study, the estimated time had a good agreement with the measured one. Therefore, the proposed model can be applied to the condition of the low output force, which the previous model cannot be applied to.

The purpose of this study was to examine reproducibility of recruitment properties of the spinal reflexes evoked by a transcutaneous spinal cord stimulation （tSCS） between days. Twenty males （25.8 ± 3.4 years） participated in this study. Experiments were conducted while the subjects were in the supine position. Recruitment curves were obtained from the spinal reflexes evoked by tSCS in two consecutive days. A paired-pulse stimulation with 50 ms inter-pulse interval was delivered to confirm that responses were caused by activation of the sensory fibers. Surface electromyography （EMG） of eight muscles in the lower-limbs （i.e., foot, shank, and thigh muscles） was recorded. Peak-to-peak EMG amplitudes of the first response was calculated for each muscle when no response was observed in the second response. Threshold intensity of the responses was defined as the minimum stimulation intensity that produced the responses, and maximal slope of the responses was determined by fitting six-order polynomial function to the recruitment curve. Inter-day reproducibility of the recruitment parameters was quantified using intraclass correlation coefficients （ICC）. ICCs of threshold intensity for each muscle ranged between 0.487 and 0.874, and ICCs of maximal slope ranged between 0.474 and 0.964. These results suggest moderate to high reproducibility of the parameters of the recruitment curve of spinal reflexes in lower-limbs. Therefore, spinal reflexes evoked by tSCS could be useful in longitudinal neurophysiological studies.

We examined the influence of Jack-knife stretching on lower limb muscle tightness and kicking motion in adolescent soccer players. It is hypothesized that performing Jack-knife stretching for six months, improves flexibility of the lower extremity muscles and decreases posterior pelvic tilt during kicking motion. Twenty-two boys （mean age 12.1±1.1 years） belonging to the junior division of the professional soccer team, were included. Height （cm）， body weight （kg）， distance of long seat type body anteflexion （cm）， straight leg raising （SLR） （degrees）， heel hip distance （HHD） （mm） and posterior pelvic tilt （degrees） were assessed. Jack-knife stretching was carried out five times, in the morning and at night, for six months. The height and weight at initial measurement and after six months were 154.0±10.4cm and 45.3±9.3 kg, and 158.1±10.1cm and 48.0±9.6kg, respectively. Distance of long seat type body anteflexion was 35.5±7.1cm, 42.0±6.0cm （p = 0.004）．SLR was 64.9±6.8ﾟ, 75.3±7.2（P<0.001）．HHD was 121.5±32.6mm, 111.1±24.9 mm（P=0.008）．Posterior pelvic tilt during an in-step kick was significantly increased. Jack-knife stretching improves the distance of long seat type body anteflexion, SLR and HHD. However, posterior pelvic tilt during an in-step kick was significantly increased.

Over months, prior to the weigh-in （24h before the match）， professional boxers （Boxers） typically keep training and reduce their body mass empirically to gain a strength/size advantage over opponents. Using voxel-based morphometry （VBM）， resting-state functional magnetic resonance imaging （rs-fMRI）， we included twenty male licensed Boxers （26.7±4.0years） in the time point of one-month before match （Term1, mean body mass index [BMI]: 22.0±1.3） in comparison to seventeen age-sex-BMI matched controls （27.8±3.7years, BMI: 21.5±1.6）．Then we longitudinally followed the Boxers at the time point of within-one week before the match （Term2, BMI: 20.6±1.3） and one-month after the match （Term3, BMI: 22.4±1.3）．In Term1, Boxers presented significant higher gray matter density compared to controls, in bilateral anterior insula （AI） （left: p<0.001; right p=0.023）， cluster level FWE [family wise error] corrected）， generally representing sensory integration. In Time2 and Time3, Boxers’ posterior cingulate cortex represented correlated gray matter densities with BMI change. In rs-fMRI analysis seeding the AI clusters, significantly lower FC were found with precuneus （p=0.031） in Boxers. No significant FC were found in Term3. These findings suggest the bilateral AI represented specific structurer in Boxers, and the posterior cingulate cortex represented BMI change before and after the match. Because the posterior cingulate cortex has the pivotal role in adopting for the surrounding environments, the functional plasticity in Boxers that lower connectivity in precuneus which is a part of posterior cingulate cortex, suggests their specificity that they have to reduce their weight regardless of their environments.

This study aimed to clarify which musculature characteristics is directly related with improvement of sprint performance by examining trunk and lower extremity muscle cross-sectional area change before and after training period. Twelve collegiate male sprinters and hurdlers took part in this study （age 20.4±0.5 yrs, height 172.3±4.5 cm, body mass 64.7±5.9 kg）．Cross-sectional images from the origin to insertion of 21 trunk and lowerlimb muscles were obtained with via magnetic resonance imaging （MRI）．The absolute cross-sectional areas of each muscle were calculated as indices of muscularity using images. The participants performed two 60-m maximal sprint on a synthetic surface track wearing spiked shoes. After experiment, they were divided two groups, one is V+ group （the participants of this group improved maximal sprint velocity of 60-m sprints）， the other is V- group （The others decreased that）．We focused the difference of muscle cross-sectional areas change before and after training session between V+ group and V- group, and explored which skeletal muscle was related with sprint performances. Significant simple correlation with maximal sprint velocity was found for 13 muscularity indices （abdominal oblique and transverse abdominal, psoas major, erector spinae, gluteus maximus, gluteus medias and minimus, vastus lateralis, vastus intermidius, vastus medialis, sartorius, biceps femoris, semitendinous, semimembranosus and gracilis）．On the other hands, change value of psoas major, erector spinae, gluteus maximus and semitendinous before and after training session is significantly different between V+ group and V- group. These findings suggest that muscularity indices of psoas major, erector spinae, gluteus maximus and semitendinous play a significant role in sprint performance.

Risk factors for knee pain in children and adolescents in the age between 10 to 15 years old were investigated. 835 subjects without knee pain were included. Factors for lower limb tightness, lower limb alignment were measured at baseline, and growth rate was calculated by monitoring height three times per year. A survey for physical activity and occurrence of knee pain was conducted every month by a self-reported questionnaire. New-onset knee pain was used as the objective variable, and school year, sex, growth rate, physical activity calculated by HSS Pedi-FABS, intercondylar distance, quadriceps angle, foot posture index, heel buttock distance, straight leg raise angle, and ankle dorsiflexion angle were used as explanatory variable to perform multiple logistic regression analysis. Higher school grade and higher physical activity were significant factors to predict occurrence of knee pain.

Many studies have attempted to determine the associations between blood and urine biomarkers and muscle damage and atrophy. However, poor correlations between the changes in biomarker levels and the magnitude of muscle damage and atrophy have been reported. Recently, the N-terminal fragment （N-titin） of titin （connectin）， a giant sarcomeric protein that is involved in muscular passive tension and viscoelasticity, has been reported to detect muscle damage in patients with skeletal muscle dystrophy and in healthy volunteers with endurance exercise. In the present study, we evaluated whether urinary N-titin is changed during a muscle atrophy period and whether its increase reflects muscle atrophy. C57BL/6 mice （male, 10 weeks of age） were used of this study. Urine samples were obtained after sciatic nerve removal surgery to induce muscle atrophy. We measured the urinary levels of N-titin with a highly sensitive ELISA system. 11 days after sciatic nerve removal surgery, dissection was performed and the limb muscle was removed and weighed. Unfortunately, although skeletal muscle weights were predominantly reduced and mRNA levels of Atrogin-1 and MuRF-1 as markers of muscle atrophy, were increased, there was no significant changes in urinary titin levels. These results suggest that it is difficult to identify the muscle atrophy with urinary titin levels.

High intensity exercise has been reported to induce increases in systemic parathyroid hormone （PTH） levels. PTH is involved in the conversion of 25-hydroxyvitamin D （25 （OH）D） to 1 alpha, 25-hydroxyvitamin D3 （1α, 25 （OH） 2D3）; thus, 25 （OH）D levels may potentially decrease through conversion to 1α, 25 （OH） 2D3 following exercise induced increase in PTH levels. The purpose of this study was to investigate the influence of differences in exercise volume on 25 （OH）D levels and bone mass. Seven-week-old female C57/BL6j mice were divided into three groups: sedentary （CON, n = 5）， exercise once a day （EX-1, n = 5）， and exercise three times a day （EX-3, n = 5） . The exercise groups were subjected to 30 minutes of treadmill running at 12 m/min on a 5° incline; animals exercised 5 days a week for 4 weeks. Following the final exercise session of week 4, serum PTH levels had significantly increased in the EX-3 group compared with the CON group （p < 0.05）．At the same time point, the number of mice where no serum 25 （OH）D could be detected were 50% in the EX-3 group. Muscle wet weight was increased in the EX-3 group compared with the CON group （p < 0.05）．Bone mineral density （BMD） was increased in the EX-3 group compared with both the CON （p < 0.05） and EX-1 groups （p < 0.05）．This study was suggest that increased exercise volume has the potential to decrease 25 （OH）D levels, although it was seen to be increased in muscle wet weight and BMD. Therefore, we conclude that athletes with intense training regimens should consume diets rich in vitamin D.

It is reported that low carbohydrate diet blunts insulin secretion in response to glucose load via reduced SGLT1 in the small intestine. This adaptation may be a disadvantageous for athletes to recover muscle glycogen and protein synthesis after an exercise bout. The purpose of the present study is to examine the effects of low carbohydrate diet on muscle glycogen recovery and protein synthesis after an acute bout of exercise. Six-week old C57BL/6 male mice were trained by means of voluntary running wheel for 6 weeks, then divided into two groups, control diet （CON） and low carbohydrate diet （LC）．The mice were fed respective diet for 2 weeks and continued running training. After 2-week diet intervention, all mice were subjected to 30-min treadmill running, then immediately after cessation of running, mice were administrated glucose solution （2 g/kg body weight）．Muscle and small intestine were dissected out 2 h after glucose administration. Muscle glycogen concentration and SGLT1 protein content in small intestine in the LC group were lower than those in CON group. However, phopsho-p70S6K protein content did not differ between groups. These results suggest that a low carbohydrate diet feeding delays muscle glycogen recovery after an exercise bout.

To find the effect of the heel height of the pumps for businesses and the age on the walking performance, the 3D motion analysis, the electromyography, the postural movements analysis, the foot pressure measurement were conducted for the 7 young and the 5 middle aged female people. The motion analysis was performed for naked foot and pumps of and heel height 3cm（h3）， 5cm（h5）， 7cm（h7）．We calculated ⊿S, which is the difference between the maximum and the minimum value of the gait cycle curves for the angle, angular velocity, and the angular acceleration of the leg joints of the knees and ankle. The tendency of ⊿S of a right knee joint angle, ⊿S of the right knee angular speed and ⊿S of a right knee angular acceleration became biggest for 3cm heel pumps （h3）．In case of long time&apos;s walking, the decrease of ⊿S of each joint occur for the a middle age group with high heel pumps. The electromyogram became highest at the muscle of tibias anterior and the gastrocnemius of 7cm heel pumps （h7）．For postural movements analysis, the length of the track increased in putting on higher heel pumps. For pressure measurements, while a weight track bent by h3 and h5, it was a straight movement in h7.

Key words: 3D motion analysis, electromyography, postural movements analysis，foot pressure measurement.

Knowledge of the running mechanics will provide greater insight into the manner in which lower-extremity amputees wearing running-specific prostheses （RSPs） regain running capacity and compensate for replacement of an active leg with a passive prosthetic implement. Despite joint moment is commonly-used biomechanical parameters to enhance our understanding of muscular effort and joint control during running, it remains unclear about joint moment of transfemoral amputees to improve running speed. The purpose of this study was to investigate joint moments during maximal sprinting in unilateral transfemoral amputees wearing RSPs. We recruited four paralympic contestants and ten non-paralympic contestants with unilateral transfemoral amputation. The participants performed maximum sprinting over an indoor 40-m straight runway, where seven force platforms and optical motion capture cameras were placed approximately 22 m from the starting line. The prosthetic “ankle” joint was defined by the markers on the most acute point on the prosthesis curvature attached to the midpoint between the RSP medial and lateral edges. Joint moments were calculated through an inverse dynamics approach. Paralympic contestants had greater hip extension moment in intact limb than non-paralympic contestants. Further, in the prosthetic limb, paralympic contestants also had greater plantarflexion moment than non-paralympic contestants. The results of the present study suggest that strength training for muscles around hip joint and loading on running-specific prosthesis may be key factors to improve running speed for unilateral transfemoral amputees.

Quadriceps femoris （QF） muscle weakness is especially common after knee joint injury and occurs due to both muscle atrophy and deficits in voluntary activation. An important cause of QF voluntary activation deficits is arthrogenic muscle inhibition （AMI）．In present study, neurological changes of the QF induced by prolonged vibration stimulation was used as a model of the AMI. This is because neurological changes leaded by prolonged vibration stimulation were similar to that observed in the QF with the AMI. The purpose of present study is to investigate how the neurological abnormality would affect to reflex activities of thigh muscles during unexpected landing. The prolonged vibration stimulation significantly enhanced the average EMG during time frame of the middle latency reflex （MLR） of the vastus lateralis （VL） and the biceps femoris （BF） only after the surprised landing even though no alternation of the MLR of the VL and the BF in both normal landings were found even after the application of prolonged vibration stimulation. These results suggested that neurological alternations leaded by the prolonged vibration stimulation have no effect on landings accomplished by accurate feedforwarded information from brain based on visual estimation. However, only when discrepancy was recognized between the feedforward from brain and feedback from the proprioceptors in the lower limbs, the MLRs of the VL and BF were enhanced. the mechanism of the enhancement of the MLR via the attenuated afferents from proprioceptors to their brain might work as a preparatory mechanism in case startle events were imposed to them. In other words, in advance, a human brain might produce neurophysiological state in which the MLR could easily be enhanced via disinhibited Ib interneurons as a compensatory strategy to prepare startle events.

Purpose: Wheelchair race of the Paralympic games have become increasingly popular in the last few years. Development of a wheelchair is record improve very it being important of an athlete. However, there are little quantification of mechanical output of an athlete playing a game and kinematic information while development and study of a wheelchair advance. The purpose of this study was to biomechanics analysis of wheelchair sprint racing the 100m and 400m race simulations using wheelchair ergometer. Methods: The six wheelchair athletes （age:40.5±7.2yrs. BH:165.5±7.6cm, BW:55.5±8.7kg, Class: T53,54, 100m time:16.08±1.03s, 400m time:54.41±7.37s） were participated in this study. Subjects were performed 100m and 400m race simulation each wheelchair racer attach on wheelchair ergometer system （1kHz, KEKU,Canada）. Reflective marker was attached to the upper limb anatomical point: acromion, humeral lateral epicondyle, ulnar styloid, Finger the second metatarsal. Upper limb extremity kinematics data was analysed using the motion capture system （200fps, BTS, Italy）. During race simulate mechanical model was applied form primary research. One stroke wheelchair power output was calculated from push force and disk velocity. One cycle time of spatio-temporal parameters were determined by power curve, stroke frequency （SF） was calculated from the reciprocal number. Stroke length was divide average of one cycle velocity by frequency （SL）. Mechanical power output and spatio-temporal parameters of race simulations were indicated Mean±SD each 10m or 50m phase.

Results: In 100m race simulation, maximum speed was appeared just before 100m, but the 400m race simulation was indicated between 100m and 150m phases. Stroke frequency was not difference between 100m and 400m race simulations. As for the velocity of both races, what SL influenced than SF was accepted. As for the force, decrease was present, but the power display was steady in 100m race simulation. On the other hand, in 400m race simulation was indicated that decrease both force and power output. Maximum velocity was not significant difference between 100m（8.13±0.8m/s） and 400m（8.45±0.41m/s） race simulations. Conclusions: This study suggested that in wheelchair race, rate of velocity was key factor in 100m, whereas maintenance of force out put was important in 400m. Higher performance was characterized as narrow rim range power production in both 100m and 400m racers.

Ubiquitin-proteasome system is known as a major proteolysis in skeletal muscle. Previous studies suggested that proteasome is important to homeostasis of skeletal muscle. However, the role of proteasome during exercise has not been elucidated yet. Therefore, in this study, we aimed to elucidate the role of proteasome in skeletal muscle during endurance exercise, and hypothesized that skeletal muscle specific proteasome gene knock out mice have lower ability of endurance exercise than control mice.As a result of endurance exercise test, skeletal muscle-specific proteasome gene knock out mice showed significant decrease in running time compared with control mice. These findings suggested that proteasome in skeletal muscle might contribute to endurance exercise. The role of proteasome during endurance exercise needs to be further examined.

In this preliminary study, we aimed to examine the influence of self-massage after exercise on "quality of sleep" and physical condition, the next day. Additionally, we aim to clarify the range of effect, applicability, and limitations of self-massage after exercise.

Our study included five male university students and graduate students. Participants provided consent to participate in the study. After entering the laboratory, the subjects participated in a 10-minute warm-up followed by a 10-minute work-out. After the work-out, self-massage was performed for 10 minutes. The massage was focused mainly on the lower body under massage and restraint conditions. Control condition utilized the same 20-minute warm-up and work-out routine and were followed by 10 minutes of rest in the seated position. Subsequently, subjects proceeded to a bed in the temperature controlled laboratory overnight for evaluation of sleep quality, measured using the electrophysiological index.Our results indicate that heart rate during sleep tended to be significantly higher under the control condition. Additionally, although there was no significant difference between the stage 2 latency and the stage 3 latency, both were shortened in the massage condition but not in the control. Thus, the results suggest that self-massage care after intense exercise may have a positive effect on the quality of sleep. However, in this study, the number of subjects was kept at a minimum （5 people） as saliva analysis was not cost-effective; hence, it is necessary to further review the massage site and massage duration in the future.