We have found that macrophage migration inhibitory factor （MIF） is secreted from C2C12 myotubes into culture media. In order to evaluate roles of MIF on glucose metabolism in skeletal muscle, extensor digitorum longus and soleus muscles were isolated from mice and treated with recombinant MIF in in vitro muscle incubation system. MIF itself did not affect to glucose transport in both type of muscles. However, glucose transport induced by half-max dose of insulin was diminished by co-existence of MIF in the buffer of soleus muscle incubation. These results suggest that MIF is a negative regulator of insulin-induced glucose transport in skeletal muscle. These results show that MIF is a novel myokine contributing to glucose metabolism and can be a new target molecule for prevention and treatment of diabetes.

Leg compression stockings have been used to prevent deep vein thrombosis. On the other hand, they often decrease blood flow in the skin and increase the mental stress caused by high pressure. This study aimed to obtain fundamental data regarding universal specifications for elastic leg compression stockings. The effects of pressure applied on each part of the leg, i.e., foot, ankle, calf, and thigh; on the blood circulating system; and the autonomic nerve response were determined. The results obtained were as follows. In the sitting posture, the skin blood flow decreased with increase in the leg pressure, in accordance with the distal end of the limb. In the sitting and supine postures, the heart rate decreased greatly with increase in the pressure on the calf. This indicates that the venous return improved. When pressure was applied on the calf, the decrease in the LF/HF, that is the ratio of low frequency to high frequency of the R-R interval, was greater than that seen in the others. Therefore, we concluded that pressure on the calf is most effective in increasing venous return.

The purpose of the present study was to determine the influence of wearing compression garments （compression tights） with different pressure intensity on muscle function, metabolite and endocrine responses, muscle damage and inflammatory responses to 120 min run at moderate intensity. Eight healthy young men conducted four trials on different days, consisting of [1] trial with wearing compression garments of heavy pressure intensity （approximately 40 hPa, High），[2] trial with wearing compression garments of moderate pressure intensity （approximately 20 hPa, Middle），[3] trial with normal sport garments （pressure intensity was set below 10 hPa, CON）．Each trial was performed with randomized orders, and four weeks of rest period were provided between the trials. Exercise consisted of 120 min of running on treadmill at 60% of maximal oxygen uptake （V･O2max）．Time-courses of changes in power output for lower limb muscles （maximal jump height），heart rate, ratings of perceived exertion （RPE），metabolic and endocrine responses, muscle damage and inflammatory responses were evaluated.

Motion analysis is an important tool to accurately measure motion during sports activity. Method of motion analysis so far are mainly two-dimensional, So was insufficient. The purpose of this study is to analyze the movement of the upper limbs and trunk of canoe athletes during upper limb elevation or paddling using electromagnetic goniometer （three-dimensional motion analysis equipment）．This time, we compared healthy canoe athlete and para canoe athlete on upper limb and trunk movement during paddling with an electromagnetic goniometer. Healthy canoe athlete showed greater upper limb elevation movement, while para canoe athlete tend to have greater scapula motion. Canoe competition requires trunk rotation movement, para canoe athlete with may be using more scapular motion to compensate for lack of trunk rotation of. Our findings suggest that healthy canoe athlete demonstrate greater trunk motion. Therefore, scapular flexibility and control are necessary in the para canoe athlete who is hard to convey a power by kinetic chain from the trunk like healthy canoe athlete. It was suggested that para canoe athlete receiving different training than healthy canoe athlete.

As pathological analysis of adaptive sports, we focused on risk factors of injury in wheelchair tennis and studied the characteristics of trunk movement and upper limb movement during the serve motion. We also report our review of propulsion motion and seat pressure distribution in wheelchair marathon for future device development.

There are not enough reports about elbow joint injury of disabled sports. In preset study, we investigated about the observations of elbow joint in wheelchair marathon athlete for the prevention of elbow joint injury. Thirty five wheelchair marathon athletes, who participated in Oita international wheelchair marathon race, were recruited for present research. Elbow pain on motion, tenderness, Tinel's sign, ulnar nerve palsy and range of motion on elbow were investigated. Five athletes had elbow pain on motion, and 15 athletes had tenderness. The tenderness parts of 14 athlete were left lateral epicondyle of humerus. Seven athletes had left Tinel's sign and 6 athletes had right Tinel's sign. Two athletes had left ulnar nerve palsy. These abnormal findings on left side elbow were more than right side. There were no limit of range of motion on elbow. From present results, about half of wheelchair marathon athletes had some abnormal findings on elbow, and the abnormal findings had laterality （left side > right side）．Moreover, the most high frequency parts of tenderness was lateral epicondyle of humerus. We assumed that these results might be the one of important new findings for the prevention of elbow joint injury.

We fabricated wearable flexible humidity sensor that can measure human sweat. Our sensor is based on Ionic-liquid-Gel-coated Fabrics and Cloths （IG-Fabric/Cloth）．We use EMIMBF4 as ionic liquid, which has a characteristic that it absorbs H2O and changes its impedance. For the humidity sensor substrate, we use “Bemcot TR-7F” （Asahi Kasei corp., Japan） and “Kimtowels” （NIPPON PAPER CRECIA Co., LTD, Japan） as fabric and Cotton and Polyester as cloth. Fabrication steps of ionic-liquid-gel-coated fabric and cloth are as follows. First, we prepare the mixture of ionic liquid and PolyVinylidene DiFluoride （PVDF） and Dimethylacetamide （DMAc） as ionic liquid gel solution. Then we dip the fabric and cloth into the ionic liquid gel solution for 5 minutes. After picking up, we baked the fabric on the 80ºC hotplate for 30 minutes. To evaluate IG-Fabric/Cloth humidity sensor, examined the relation between relative humidity and IG-fabric impedance change. There is linearity in humidity and resistance change. From the measurement data of sensor response speed test, the response speed τ63 estimated as around 0.7 seconds. This is 10 times faster than commercial CMOS humidity sensor. This is because IG-fabric has a large surface area and high gas permeability, compare to silicon wafers. We also evaluated the flexibility of our humidity sensor and showed high flexibility of our sensor. As a demonstration, we fabricated IG-Cloth based humidity sensor on the surface of polyester T-shirt and measured sweating of the human doing exercise and cooling down. From the experiment, we observed the impedance change of IG-Cloth according to the examinee’s activity. This sensor has many applications such as flu-mask-type human breath sensor that can monitor human breath, and wearable humidity sensor that can measure human sweat to decrease the risk of heat stroke.

Muscle damage induced by marathon running has been often evaluated by changes in maximal voluntary contraction torque or blood creatine kinase activity. However, these parameters cannot characterize the region and extent of muscle damage of individual muscles. It was recently reported that individual muscle stiffness assessed by ultrasound shear-wave elastography can quantify the extent of exercise-induced muscle damage. The present study aimed to evaluate the extent of marathon running-induced muscle damage of the lower limb, by using ultrasound shear-wave elastography. Twelve college recreational runners participated in the present study. Muscle stiffness were obtained from the vastus medialis, vastus lateralis, biceps femoris, semitendinosus, semimembranosus, and medial gastrocnemius, before and 1-3 days after the marathon running. Significant increase in muscle stiffness was observed only in the medial gastrocnemius after 1 and 2 days after marathon running. These results indicate that, in recreational runners, muscle damage induced by marathon running occurred in the plantar flexor, not in the quadriceps femoris and hamstring. Moreover, it is suggested that the muscle damage of the plantar

Introduction: Postprandial abnormal glucose elevation （PPGE） is one of the risk factors ofcardiovascular disease （CVD） in both diabetes and nondiabetes groups. Effective control of PPGE might prevent the chronic diseases such as CVD. However, there is no consensus on optimal exercise timing to reduce PPGE. The purpose of this study was to determine the most effective timing of exercise. Method: Six participants completed the 4 different exercise patterns in random order, which were 1） no exercise, 2） pre-meal exercise （jogging）， 3） post-meal exercise （jogging）, 4） breaking up sitting time （3sets of 1min jog+30sec rest, every 30min, BST） . Pre and post-meal exercise pattern was 20 sets of interval exercise: 1min jogging and 30 second rest at the lactate threshold intensity of running （62.4±12.9% V・O2max）． Blood glucose concentration was measured continuously during each of the patterns. Heart rate （HR） was measured after the first bout of exercise in a day. Timing, order and composition of the meals was the same in each test Result: Heart rate was significantly lower for BST than pre-and post-exercise patterns. Peak blood glucose concentration attenuated in BST after breakfast was lower compared with pre （p=0.072） and post-exercise （p<0.05）． After lunch BST glucose concentration was lower than for post-exercise （p<0.05）． After dinner was no significant differences between patterns. Area under curves of glucose concentration during 24 hours and 2 h postprandial was not different for each pattern. Conclusion: The results of the study suggest that BST was more effective than pre-exercise and post exercise in preventing PPGE, especially in the morning.

Studies have shown that a fingertip lightly touching a stable surface reduces postural sway, by providing additional tactile feedback information to the postural control system. In the present study, we examined whether or not water immersion of a fingertip enhances the postural control system during quiet standing. Eight young and nine elderly subjects maintained quiet standing for 40s with the index fingertip in the water （water touch, WT） or on the stable surface （light touch, LT）．The temperature of water in the WT condition was 20, 30, or 40℃ for young subjects and 30℃ for elderly subjects. In the control condition （CON），a no touch trial, the subject quietly stood on a force platform for 40s, with their arms by their sides. In the young subjects, eight trials were conducted for each condition; while the elderly subjects completed three trials for each condition. The results showed that, in the young subjects, the mean velocities of the foot center of pressure （CoP） in the anteroposterior （AP） direction was significantly reduced in the LT and WT at individual optimal temperature, compared to that in the CON condition （P<0.05）．On the other hand, in the elderly subjects, the power of low-frequency CoP sway （below 1Hz） in the AP direction significantly decreased at LT and WT conditions （P<0.05）．These results indicate that WT can enhance the postural control system, as well as the LT. This promises the neurophysiogical effect of water exercise on the postural control system.

Excessive elevation of internal body temperature causes a significant strain on either the brain function or the locomotive system. Although hyperthermia impairs psychological and working memory performances, the effect of hyperthermia on cognitive processing remains unknown. We hypothesized that a passive heat stress impaired the cognitive function when the internal temperature was excessively increased. sixteen healthy males performed an auditory oddball paradigm before and after heat stress （Pre and Post） and when esophageal temperature was increased by 0.8 ℃ and 2.0 ℃ （Mild and Severe）．The reaction time and event-related potentials （ERPs） were recorded in these four sessions. As a countermeasure, subjects performed the same sessions without heat stress （i.e. normothermic condition）．The reaction time was shortened while esophageal temperature was elevated relative to the Pre but did not change in the normothermic trial. However the peak latency and amplitude of N100 component did not change throughout the experiment. Although the latency of P300 component was unaffected due to heat stress, the amplitude of P300 was significantly reduced at the Severe and Post relative to at the Pre. These results suggest that excessive elevation of internal temperature impairs cognitive processing but not auditory processing.

Purpose: This study aimed to examine the relationship between one-leg stand up test results and muscle mass or strength. The possibility of using this test as a simple assessment tool for predicting sarcopenia was also evaluated. Methods: A total of 575 men and women aged 30–89 years participated in this study. The ability to stand up on one leg from a 40-cm-high seat was assessed. The appendicular skeletal muscle mass was measured using dual-energy X-ray absorptiometry, and the skeletal muscle index was calculated by dividing the appendicular skeletal muscle mass by the square of the height （kg·m-2）. Hand-grip strength and leg-extension power were also evaluated. Results: The subjects who could not stand up on one leg had significantly lower hand-grip strength and leg-extension power （P < 0.05）, and they also had a higher prevalence of low muscle mass （odds ratio: 2.79） or low muscle strength （odds ratio: 3.07）. Sensitivity and specificity of one-leg stand up test （for the low muscle mass or low muscle strength） were 48–56% and 72–74%, respectively. Conclusion: Sarcopenia could be partially predicted by the suggested one-leg stand up test.

The purpose of this study was to clarify the possibility of intramuscular fat （IMF） could be the risk factor of metabolic syndrome in obese children. Thirty-seven obese boys and girls participated in this study （age, 10.4 ± 2.1 year-old; height, 146.2 ± 13.4 cm; weight, 56.1 ± 16.5 kg; percentage of overweight, 41.1 ± 16.8%）． The subjects were divided into three groups based on percentage of overweight, i.e. mild obesity group, moderate obesity group, and sever obesity group. This study was conducted a part of obesity treatment for the subjects and was approved by the institutional review board of local committees. Computed tomography （CT） images were taken at the mid-thigh and umbilicus levels. Using the CT images, IMF index of the quadriceps femoris （QF）， hamstrings （HM） and adductor （AD） muscle groups based on mean grey scale level of the interested muscle groups and visceral fat cross-sectional area （CSA） was calculated. For the mid-thigh CT image, skeletal muscle CSA and subcutaneous fat was also calculated. Plasma triglyceride, FFA, HDL-cholesterol, total-cholesterol, glucose, and HbA1c were measured from fasting blood drop. IMF index of QF, HM and AD was significantly different in all comparisons: HM was the lowest （1066 ± 6 a.u.）， meaning largest IMF depot, and QF was the highest （1080 ± 3 a.u.）， meaning smallest IMF depot. Stepwise multiple regression analysis revealed that none of independent variables were extracted to predict IMF index in QF. For IMF index in HM, visceral fat CSA per body weight and FFA were extracted （R=0.483, P < 0.05）． Interestingly, visceral fat CSA per body weight was the only extracted variable to predict IMF index in AD （R=0.531, P < 0.05）． These results suggest that IMF in hamstring and adductor could be a risk factor of metabolic syndrome in obese children.

Previous studies have reported that respiratory muscle training improves performance during prolonged high-intensity exercise; however, the mechanism remains unclear. With an aim to gain insights into the underlying mechanism, we simultaneously monitored respiratory and lower limb muscle oxygenation patterns using near-infrared spectroscopy （NIRS） during high-intensity cycling exercise before and after 6 weeks of inspiratory muscle training. Sixteen healthy young men were assigned to either experimental （inspiratory muscle training : IMT） or sham （SHAM） training groups and underwent inspiratory muscle training for more than 5 days per week for 6 weeks. The subjects underwent constant load test at 90% V・O2max on a cycle ergometer until exhaustion both before and after training. Oxygenation in both intercostal and vastus lateralis muscles were measured using NIRS during the test. In addition, maximal inspiratory pressure （MIP） was measured using spirometer every 2 weeks for the duration of the training. After inspiratory muscle training, MIP increased significantly in the IMT group but not in the SHAM group. Furthermore, time to the limit of exercise tolerance prolonged significantly in the IMT group but not in the SHAM group. However, no significant changes were found in oxygenation in both intercostal and vastus lateralis muscles in both the groups. These findings suggest that inspiratory muscle training improves high-intensity cycling exercise performance by factors other than enhanced oxygenation in both respiratory and lower limb muscles.

It is unclear what brain status is appropriate for motor learning. More over, the brain activity should extract from the brain activity during preparation to reveal the appropriate brain status because the brain activity related to the motor execution contaminates the brain activity related to preparation and planning during motor learning. The purpose of this study is to reveal the correlation between the good performance of the motor learning task and brain activity using EEG or fMRI. Nine and five right-handed healthy volunteers participated in the fMRI and EEG study, respectively. They were asked to control the cursor using a joystick with non-dominant hand and follow the random moving target. Brain activity was recorded by fMRI or EEG. There was the significant correlation between the alpha and beta power in the left visual cortex during preparation and the task performance in the fMRI. While, there was the significant correlation between the alpha and beta power in the left inferior frontal gyrus and the alpha power in the left premotor cortex, and the task performance in the EEG result. These results showed that low activity in the left visual cortex, high activity in the left inferior frontal gyrus and the left premotor cortex cause the good performance of this visuomotor target following task.

Aim: Physical exercise is important for limiting fat mass and preventing obesity. During the low temperature phase of the menstrual cycle, in women, aerobic exercise before lunch is effective in helping maintain lipid consumption. This study aimed to clarify the conditions under which body fat is easily consumed during aerobic exercise, which can be easily performed. We also aimed to clarify the effect of supported pants on consumption of body fat. Methods: The subjects were eight young Japanese females aged 20s who were slightly a slender to obese one （BMI: 18.7-24.5）． They woke at 06:00 after 7 hours of sleep and took the prescribed diet until 07:30. They then entered a climate-controlled room （24.5℃, 50.0%）． Subjects were seated for one hour while wearing a short-sleeved 100% cotton t-shirt and one of the following: 100% polyester running pants （A）， basic pants with 80D yarn （B）， 80D yarn pants with a partial modification of pressure with supporting material （C）， or 110D yarn pants with the same design as C （D） made from the preliminary experiment. They then engaged in aerobic exercise with loads from 40% to 65% of the maximum heart rate and a total of 30 minutes exercise. Respiratory metabolism and heart rate were measured with a bicycle ergometer. The amount of energy/adipose/carbohydrate was calculated from RQs and oxygen intake. Results/Findings/Conclusion: Total lipid consumption of aerobic exercise was reduced 12.2–16.1 times larger than control at rest. Body fat was reduced significantly larger （1.3 times） with C compared with A as control. C and D pants, which are partial compression garments, helped to reduce body fat more efficiently than A （non-compression garment） or B （constant compression garment）． And if the same exercise intensity, the heart rate was controlled, but oxygen intake increased, it then was thought adipose consumption increased. Our findings show partial compression garments may be most effective in reducing body fat.

The purpose of this study was to examine effects of acute aerobic and resistance exercise on cognitive function, plasma catecholamines （adrenaline, noradrenaline, and dopamine）， serum insulin-like growth factor 1 （IGF-1）， and serum cortisol. Eight participants （mean ± SD, age = 21.6 ± 0.5 yr; height = 1.75 ± 0.04 m; body mass = 72.2 ± 5.7 kg, peak oxygen uptake = 53.4 ± 6.5 ml/kg/min） performed cognitive tasks before and after either aerobic exercise corresponding to 40% of peak oxygen uptake （98.8 ± 12.4 W） or resistance exercise with a resistance tube. We measured plasma catecholamines, serum IGF-1, serum cortisol, blood glucose and lactate concentration, and ratings of perceived exertion （RPE） before and after exercise. Cognitive task was a Go/No-Go task that requires response inhibition and selective attention. We did not observe significant improvements in cognitive function after each exercise, probably due to a low sample size. Nevertheless, we found that increases in plasma adrenaline, noradrenaline, and dopamine following both aerobic and resistance exercise. Serum IGF-1 increased after resistance exercise, while it did not change after aerobic exercise. Similarly, blood lactate concentration also increased only after resistance exercise. Serum cortisol tended to decrease after exercise. In the present study, we found no differences in RPE before and after exercise. These findings will help to understand the effects of acute aerobic and resistance exercise on cognitive function. To understand physiological mechanisms underlying improvements in cognitive function following acute aerobic and resistance exercise, further studies are required with large sample size.

The purpose of the present study was to examine the factors influencing previously reported exercise-dependence in muscle hypertrophy of the biarticular thigh muscles （i.e., single-joint training induces sizable hypertrophic response while multi-joint training does not）, through measurement of muscle activation patterns during a multi-joint exercise. Twelve healthy men performed leg press at a load corresponding to 80% of one repetition maximum （1RM） until exhaustion. Surface electromyographic （EMG） signals were obtained from the quadriceps femoris （vastus lateralis, vastus medialis, rectus femoris） and hamstrings （biceps femoris, semitendinosus, semimembranosus）, and root mean square values of the EMG signals （RMS-EMG） during each repetition were determined （experiment 1）． In the experiment 2, five healthy men conducted leg press at a 40% of 1RM （3 sets with 16 repetitions） and an 80% of 1RM （6 sets with 4 repetitions） load on separate days （separated by one week）． In addition, transverse relaxation time （T2）-weighted magnetic resonance images of the thigh were obtained before and immediately after the leg press. The T2 of each muscle at mid-thigh was calculated. In the experiment 1, significant increases in the activation of the vastus lateralis and medialis were found following fatiguing leg press, whereas those of the biarticular muscles did not change except for the biceps femoris. In the experiment 2, the leg press exercise induced an increase in T2 of the monoarticular muscles, but not of the biarticular muscles. The relative increase in T2 of each muscle was similar between the two exercise intensities. These results suggest that activation patterns of the thigh muscles differ between monoarticular and biarticular muscles. These differences can explain the lack of hypertrophic response of the biarticular muscles following multi-joint training found in previous studies.

We examined the changes in skin-gas acetone concentrations following the 60% heart rates （HR） max cycle exercise by the portable skin-gas acetone analyzer using electrochemical sensors. The standard acetone gases significantly （r=0.992, p<0.05） related to the results of same standard gas measurements by the portable skin-gas acetone analyzer. Thus, we confirmed the reliability of acetone gas measurements by the portable skin-gas acetone analyzer. Six healthy male students （22.2 ± 1.5 years; mean ± SD） volunteered as the subjects, and none of them were smokers. The subjects performed 60% HRmax cycle exercise for 30 min. Skin-gas acetone concentrations of each subject were measured from the first finger of right hand using a probe at rest, 5, 10, 15, 20, 30 min during, and 5, 10, 20 min after the exercise. HR were also measured at same point using HR monitor of the cycle ergometer. Skin-gas acetone concentrations significantly increased 20 （p<0.01） and 30 （p<0.05） min during exercise compared to the resting value, then returned to the resting value after the exercise. These results suggest that the skin-gas acetone concentrations increase following 60% HRmax cycle exercise for 30 min. Thus, the portable skin-gas acetone analyzer using in this study is reliable and useful to measure skin-gas acetone concentrations from the fingertip for only 2min.

Heavy priming exercise reduces the oxygen deficit during the subsequent heavy exercise. Current theories for the etiology of the oxygen deficit following the onset of exercise include increased bulk and local blood flow and O2 delivery （Q･） via residual vasodilation and academia/temperature-induced rightward shift of the hemoglobin （Hb） O2 dissociation curve. We used a method to quantify absolute [deoxy（Hb + Mb）， HHb] of superficial- and deeper regions of the rectus femoris （RF） muscle in 6 participants during cycle exercise, using time-resolved NIRS with adipose tissue correction. HHb of the deeper RF for both the priming- and subsequent heavy exercise showed steady state responses toward the end of exercise, suggesting matching of oxygen consumption （V･O2） and Q･ kinetics. Compared with the superficial RF, peak deoxygenation of the deep RF was not significantly different, however deoxygenation kinetics were slower （mean response time, priming exercise, 35±11 s vs. 66±26 s; subsequent exercise, 32±8 s vs. 44±22 s, p<0.05）．These data revealed temporal and spatial disparities in muscle deoxygenation responses to exercise and suggested matching of V･O2 and Q･ kinetics, thus the oxygen deficit reduced in the deeper region RF muscle, compared with the superficial RF. Further, these results suggest that deep region muscle has a greater Q･ / V･O2, which led to improve matching of Q･ -to-V･O2 thereby raising muscle and microvascular oxygen pressure and enhancing blood-myocyte O2 flux.

Animal studies have shown that regular exercise prevents high-fat diet-induced obese. Autophagy has been functionally linked to adipogenesis, obesity and type II diabetes. Here, we determined if regular exercise-induced autophagy activation is sufficient to mitigate high-fat diet-induced obese. Male C57BL/6J mice were randomly assigned into 4 groups: Sedentary normal chow （Sed-NC）， Sedentary high-fat diet （Sed-HF）， Exercise normal chow （Ex-NC） and Exercise high-fat diet （Ex-HF）．Mice in exercise group were performed voluntary wheel-running exercise for 8 weeks. Mice in high-fat diet group were fed 45% high-fat diet for 8 weeks. After exercise training periods, epididymal white adipose tissue was harvested and analyzed autophagy proteins by western blot. We showed that 8 weeks regular exercise prevented high-fat diet-induced obese, inhibited adipocyte hypertrophy and improved glucose tolerance. Autophagy flux （i.e., LC3-II protein） in Sed-HF mice was greater than Ex-NC and Ex-HF mice. These results suggest that exercise training may regulate adipose tissue homeostasis by autophagy.

The purpose of the present work was to compare the ankle joint passive torque and mechanical properties of muscle-tendon systems in the athletes of three groups with Forefoot, Midfoot and Reaefoot strike pattern in distance running. Also, its relation to athletic performance was investigated. From male subjects （71 in experiment1, 23 in experiment 2） with wide range performance level from world top class to recreational runners, the ankle joint passive torque and stiffness index of both muscle and tendon were measured using B mode ultrasound apparatus. The result of inter-group comparisons showed significant differences of performance between Rearfoot group and both Forefoot and Midfoot groups, while no significant difference was observed in ankle joint passive torque and mechanical properties of muscle and tendon. The correlation analysis revealed that athletes with high performance tend to possess high passive torque in observation of all subjects and even in that of each of Midfoot and Rearfoot groups. Additionally, athletes with high performance tend to be with high muscle stiffness index. These results suggest that high ankle joint passive torque and muscle stiffness index would influence improvement of athletic performance in distance running but the differences of effect in the variation of foot strike pattern were not clear.

Researchers have reported that athletes have more dental caries than ordinary people. Though exercise-induced dry mouth, rehydration with large consumption of sports drink and food, and poor brushing of teeth are mentioned as causes for the higher risk of dental caries in athletes, the details remain unclear. The aim of this study was to investigate the influences of rehydration on salivary flow, pH and buffering capacity during ergometer exercise in healthy volunteer participants. Ten healthy volunteers （5 males and 5 females, Ave.22.4 yr old） performed bicycle ergometer exercise at 80% of the maximal heart rate for 30-min in the 4 conditions: 1） only a sports drink for rehydration, （Aquarius, Coca-Cola & Co., Ltd., Tokyo, Japan） 2） sports drink for rehydration and gargling immediately after exercise, 3） sports drink diluted two times for rehydration, （diluted with mineral water; Evian, Danone Waters of Japan Co., Ltd., Tokyo, Japan） and 4） sports drink diluted two times for rehydration and gargling immediately after exercise. Participants consumed 150ml at one time, and received hydration four times in all. Paraffin-stimulated whole saliva samples were collected before, and right（0min）， 30min and 60min after exercise to measure the salivary flow rate, pH and buffering capacity. The salivary flow was almost constant throughout the experiment. The salivary pH decreased after exercise in condition 1. The salivary buffering capacity decreased significantly after the exercise in conditions 1 and 2. Regarding the salivary flow, pH and buffering capacity, there were no significant differences between before and after exercise in conditions 3 and 4. From these results, it was suggested that adequate gargling immediately after taking a sports drink for rehydration in association with sports and exercise was effective in oral health.

Muscle fatigue is a major limiting factor in the use of functional electrical stimulation （FES） for strength training. FES induces rapid muscle fatigue because muscle fibres have to be activated at unnaturally high frequencies to generate functional contractions. To overcome this weakness, we have proposed a unique method called Spatially Distributed Sequential Stimulation （SDSS）， and tested its advantage in isometric contractions for major leg muscles. The purpose of this project was to test if SDSS was capable of reducing fatigue for isokinetic knee extension. Eleven healthy volunteers participated. Intermittent stimulation （0.3-s on : 0.7-s off; 120-s total） was delivered to the knee-extensors using the conventional method （Single-Electrode-Stimulation; SES） （1 active electrode; 40 Hz） and SDSS （4 active electrodes, each stimulated at 10 Hz; composite 40 Hz stimulation） in separate trials, to generate isometric （0ﾟ/s） and isokinetic （180ﾟ/s） torque. Measures of fatigability included fatigue index （FI, average peak torque of last 10 contractions ÷ average peak torque of initial 10 contractions） and torque peak mean （TPM, average peak torque of all 120 contractions ÷ average peak torque of initial 10 contractions）． FIs were significantly higher for SDSS than SES during isometric （SES = 0.616±0.092; SDSS = 0.761±0.165; p = 0.002） and isokinetic （SES = 0.645±0.147; SDSS = 0.800±0.175; p = 0.002） contractions. TPM values were significantly higher for SDSS than SES during isometric （SES = 0.781 ± 0.068; SDSS = 0.846 ± 0.108; p = 0.022） and isokinetic （SES = 0.788 ± 0.103; SDSS = 0.883 ± 0.075; p = 0.014） contractions. We have reproduced previous findings that SDSS reduces fatigability of isometric contractions compared to similar sized contractions generated by SES. Further, we have extended these findings to isokinetic conditions. The present findings are important for facilitating the utility of FES for use in strength training.

The purpose of this study was to investigate the availability of salty taste sensitivity during exercise for the prevention of heat disorders in the hot environment. Twelve health young males were volunteered in this study. This study was consisted of two investigations: the basic experiment （n=6） was to verify the changes of salty taste during stay at rest for 30 minutes or exercise stress for 30 minutes （exercise intensity: 50 % of predicted HRmax） in artificial weather room, and the other field investigation （n=6） was to estimate during basketball games for twice （each game: 10 minutes） under warm environment （Temperature: 26.5 ℃，Relative humidity: 72.2 %）． The salty taste sensitivity, body weight, sweat loss, urinary electrolyte, the degree of salty appetite were measured before and after the game. Salty taste sensitivity and body weight after the exercise were significantly lower than that of before in 25 ℃, 35 ℃and the field investigation （p<0.05）． There were no large changes of Na and Cl in urine in the basic experiment. However, Na and Cl in urine after the game were significantly lower than that of before in the field investigation （p<0.05）． It may be suggested that decrease of salty taste sensitivity and increase of salty appetite sensation were observed at the different timing of Na increasing in sweat and Na decreasing in urine derived from increase of sweat loss during exercise in hot environment. Measuring changes salty taste sensitivity would objectively assess the condition in balance of body fluid during exercise and may be original one of the suggestion for safe management and conditioning during exercise in hot environment.

It is known that muscle mass is determined by the balance between protein synthesis and protein degradation. The ubiquitin-proteasome pathway is a major route of protein degradation. Recently, we reported that the muscle-specific deletion of a crucial proteasomal gene, Rpt3, in mice induced the muscle loss in mice. The purpose of present study was to clarify the metabolomic profile in skeletal muscle of muscle-specific proteasome dysfunction mice. We crossed the Rpt3 floxed mice with a transgenic line expressing Cre recombinase under the control of a myosin light chain 1 fast promoter to generate muscle-specific Rpt3-knockout mice （KO mice）．We evaluated the metabolomic profile in the skeletal muscle of control mice and KO mice by using the metabolome analysis. The appearance of skeletal muscle of KO mice was distinct from those of control mice. The absolute weights of the tibialis anterior, gastrocnemius and soleus muscles were smaller in KO mice （p<0.05）．In the metabolome analyses of the 112 metabolites, 64 metabolites were significance in skeletal muscle of KO mice compared to control mice （p<0.05）．These results suggest that muscle-specific proteasome dysfunction may induce metabolic disorders in the skeletal muscle. These findings will contribute to further clarify the molecular mechanisms of muscle atrophy.