A large number of studies have shown that acute exercise improves cognitive performance. Increase in arousal level has been suggested to be associated with cognitive improvement induced by acute exercise. However, it is still unclear which parts of the brain are responsible for increase in arousal level. The first purpose of this study was to clarify the brain areas involved in the increase in arousal level after acute exercise. The second purpose was to test if the increase in arousal level is associated with altered functional connectivity with the brain areas. Eighteen young male participants were recruited in the experiment. Experiments were performed on two separate days in a randomized crossover design. In the Exercise condition, the participants cycled an ergometer at 40% peak oxygen uptake for 30 minutes. In the Control condition, the participants rested for 30 minutes without exercise. They performed cognitive tasks before and after acute exercise or resting period, and fMRI images were acquired during the cognitive task. Cognitive task was a Go/No-Go task that requires executive function. Cognitive performance was assessed by reaction time and response accuracy. After exercise, arousal level increased and cognitive performance improved. The increase in arousal level was associated with increased activations of the left middle frontal gyrus, the right frontal pole, and the right dorsal anterior cingulate cortex. The increased activations were accompanied by increase in functional connectivity among these areas. These results suggest that the increase in arousal level is associated with the activations of the prefrontal cortex, the frontal pole, and the cingulate cortex. The present results also suggest that neural network of these brain areas appears to contribute to cognitive improvement induced by acute exercise.

The purpose of this study was to collect basic data for use in developing more comfortable sportswear through the study of skin vibration and tactile sensations. Skin vibration was measured when eight healthy young women were asked to run their fingers along nine types of sportswear material （including a control） in both high-temperature and low-temperature environments. The collected vibration wave data was then subject to an FFT analysis to determine vibration strength and median frequency. As a result of looking at skin vibration in response to （1） the physical properties of the material, （2） skin characteristics, and （3） sensory evaluations, we were able to indicate a variety of frequency characteristics in the skin vibration data and identified a high degree of correlation between the frictional characteristics of the material and skin vibration strength. In comparing the two environments, we found large variations in vibration strength in low-temperature condition and a tendency towards higher median frequency. Skin characteristics changed at low temperatures, which may have impacted the contact between the skin and materials. With the sensory evaluations, the study clearly demonstrated that the lower the vibration strength and the more low-frequency components were included in the vibration, the more readily the subjects felt smoothness, softness, and moistness; while the higher the vibration strength and the more high-frequency components were included in the vibration, the more readily they experienced roughness, stiffness, and dryness.

Endogenous antioxidant enzyme superoxide dismutase 2 （SOD2） gene polymorphisms were measured in stored DNA specimens from 6,410 men and women. Physical activity data were collected from these subjects over a 10-day period using an accelerometer. Urine levels of the gene damage marker 8-hydroxydeoxyguanosine （8-OHdG） were also measured. The relationship between amount of physical activity by intensity and urine 8-OHdG level for each polymorphism was then investigated by multiple regression analysis. Urine 8-OHdG level tended to be higher in individuals with the Val/Val polymorphism, which is believed to have low antioxidant enzyme induction activity. A significant negative relationship was found between total amount of physical activity and urine 8-OHdG level for Val/Val （β=−0.03, P<0.01） but not Ala/Val+Ala/Ala （β=−0.01, P=0.39）．By intensity of physical activity, the same relationship was found at moderate- to high-intensity tasks of ?3 metabolic equivalents （METs）， but no relationship was found at physical activity of ?6 METs. These results suggest the possibility that gene damage preventative effects of physical activity vary according to the antioxidant enzyme induction ability of the individual and the intensity of physical activity.

To evaluate the effectiveness of a 24-week program of nutritional supplementation using whey protein ingested after resistance exercise, on increasing muscle mass and physical function among elderly with sarcopenia. We carried out a randomized controlled pilot trial, in elderly with sarcopenia, aged 65-years of age or older, allocated to three groups of participants each: the exercise and whey protein supplementation group, the exercise group, and the whey protein supplementation group. A stratified randomization strategy was used for group allocation to achieve a comparable age and sex distribution among the groups. Sarcopenia was defined using the Asian Working Group for sarcopenia criteria, as follows: low hand grip strength or slow gait speed, and low skeletal muscle mass index. A 24-week program of resistance exercise, carried out twice per week, was combined with whey protein supplementation, containing 11.0 g of protein and 2,300 mg of leucine. The nutrition intake for participants in all three experimental groups was adjusted to a level of at least 30.0 kcal/ kg ideal body weight/day of total energy intake, 1.2 g/kg ideal body weight/day of protein intake, and more during the intervention period. Between-group differences in the pre- to post-intervention change in skeletal muscle mass and physical function were evaluated using an analysis of variance. The pre- to post-intervention increase in the skeletal muscle mass index was significantly higher for the three experimental groups （three group: p<0.05）． The pre- to post-intervention increase in the knee extension strength was significantly higher for the exercise and whey protein supplementation group and the exercise group, （exercise and whey protein group and exercise group: p<0.05）． However, We could not observed the increase in skeletal muscle mass index and knee extension strength was significantly greater for the exercise and whey protein supplementation group than for the exercise group. Whey protein supplementation, ingested after resistance exercise, could not be additional effective for the treatment of sarcopenia among elderly.

Developing a new training method that improves the ability of motor control is useful for rehabilitation for patients and elderly people and children for motor skill training. In order to clarify whether the stochastic resonance leads to improvement of human motor function, this study examined the effect of the subthreshold electrical stimulation on the adjustment ability of gripping force. Using the device that quantitatively evaluates the ability of adjustment of gripping （iWakka）， the subjects performed a motor task to accurately match the hand grip force to the target value presented on the monitor. After performing the practice, the trial of presenting electrical stimulation under sensory threshold （0.9 times of the sensory threshold） to the median nerve （ON condition） and the trial without electrical stimulation （OFF condition） are randomly performed. The difference between the exerting gripping force and the target value was compared between both conditions. In the ON condition, the absolute error of the target value and the gripping force in the isometric and concentric contraction was significantly lower than that in the OFF condition. It is considered that the subthreshold electric stimulation activated the central nervous system and this phenomenon improved the ability controlling the finger movement. It is useful to apply the stochastic resonance for facilitation of human sensorimotor function.

The purpose of this study was to investigate the effect of depth in squat exercise on knee extension peak torque, muscle thickness and physical functions. Twenty-one participants were randomly assigned large angle change squat （LAC-squat） groups （age, 69.1±3.3） and small angle change squat （SAC-squat） groups （age, 72.1±4.5） . Participants touch the hip on the 40 cm and 60 cm height chairs during LAC-squat and SAC-squat. They performed 2 sets of 68 times squat per day, 3 days per week, for 12 weeks, and their knee extension peak torque, muscle thickness and physical functions were measured before and after the intervention. As the result, 30 sec sit-to-stand repetition and 1 repetition maximum of leg press were significantly improved after the training in both groups （p < 0.05）．Muscle thickness was significantly increased only in LAC-squat group （p < 0.05）．These findings indicated that the weight-bearing squat training in the older adults was recommended from the perspective of the prevention of sarcopenia and the maintenance of independent activities of daily living. On the other hand, this result suggests that the difference of knee joint angle during squat training may relate with the effects of squat training.

The purpose of this study was to investigate the combined effect of internal and external cooling between exercise bouts on high-intensity endurance exercise performance in the heat. Six active males completed two trials in a random order: 1） passive rest （control trial） and 2） wearing a cooling vest and ingesting ice slurry （cool trial）．The two experiential trials consisted of two （first and second half）， 30-min cycling exercises （i.e., 25 min of cycling at 55% of maximal oxygen uptake followed by 5 min of time trial） separated by a 15-min half-time break in the heat （i.e., 35.0?C, 50% relative humidity）．In the cool trial, participants worea cooling vest, which can cool the neck, upper body, back, and side, and ingested 5.0 g/kg of ice slurry during half-time break. Time trial performance in the second half was substantially higher in the cool trial compared with the control trial. Rectal temperature at 45, 50, and 55 min and deep forehead temperature at 45 min were substantially lower in the cool trial compared with the control trial. Forehead and mean skin temperatures at 35, 40, and 45 min and neck skin temperature from 35 to 55 min were substantially lower in the cool trial compared with the control trial. Rating of perceived exertion at 50 min and thermal sensation from 35 to 50 min and at 60 and 65 min were substantially lower in the cool trial compared with the control trial. Thermal comfort and recovery rating scale from 35 to 45 min were substantially higher in the cool trial compared with the control trial. In conclusion, combined methods of internal and external cooling between exercise bouts maintained high-intensity endurance exercise performance and decreased core temperature in the initial part of the second half.

Aging-induced increase in fat accumulation causes arterial stiffness. Ectopic fat accumulation with aging may be more important than whole-body fat content for predicting cardiovascular disease. Aerobic exercise training （AT） decreases fat accumulation, concomitant with an elevation of serum level of adiponectin, as an anti-inflammatory adipokine, resulting reduction of arterial stiffness. Recently, C1q/TNF-related protein 5 （CTRP5） has been identified as a novel adipokine which is paralog of adiponectin and exerts vasodilator effect. Although AT increases serum CTRP5 levels, concomitant with a reduction of fat accumulation, the differences of AT-induced increases in CTRP5 secretion from ectopic adipose tissues remain unclear.

PURPOSE: This study aimed to clarify whether AT increases mRNA expression level of CTRP5 from ectopic fats in senescence mice.

METHODS: Seventeen 38-week-old senescence-accelerated mouse prone 1 （SAMP1） mice were divided into sedentary control （CON; n=7） and AT （voluntary wheel running for 12-weeks; n=10） groups. Expression level of CTRP5 mRNA in epididymal, perivascular, subscapular subcutaneous and brown fats were measured by using real-time RT-PCR. The vasodilatory response of acetylcholine treatment was assessed by using aortic vascular rings.

RESULTS: Compared with CON group, AT group showed significantly lower epididymal fat mass, and significantly higher vasodilatory response of acetylcholine treatment by using aortic vascular rings. However, there was no significant difference in expression levels of CTRP5 mRNA in epididymal, perivascular, subscapular subcutaneous and brown fats between two groups.

CONCLUSION: These results suggest that AT-induced increases in CTRP5 mRNA may be occurs in tissues other than epididymal, perivascular, subscapular subcutaneous and brown fats.

It is known that paired associative stimulation （PAS） can induce plastic changes in the central nervous system. The PAS involves the pairing of the electrical single pulse stimulation to a peripheral nerve and single pulse of transcranial magnetic stimulation （TMS） over the primary motor cortex. The purpose of the present study is to investigate the effect of PAS involving transcutaneous spinal cord stimulation （tSCS） and TMS on corticospinal excitability of multiple lower-limb muscles. Ten healthy males participated in the present study. In total, 120 paired stimuli were given to each subject every 9 seconds for 18 minutes. Before and after PAS, corticospinal excitability was evaluated in the rectus femoris （RF）， vastus medialis （VM）， biceps femoris long head （BF）， tibialis anterior （TA）， soleus （SOL）， and medial gastrocnemius （MG） muscles. The results showed that PAS facilitated corticospinal excitability in the BF, SOL, and MG muscles. Furthermore, facilitatory effect of PAS on corticospinal excitability was observed 30 minutes after PAS. These results indicated PAS combining tSCS and TMS could widely induce plastic changes in excitability of the lower-limb motor cortex. However, PAS did not facilitate corticospinal excitability in the RF, VM, and TA muscles. These results also showed a difference in facilitatory effect of PAS on corticospinal excitability among lower-limb muscles, suggesting the existence of a hierarchy of plastic changes in the primary motor cortex. These findings have elucidated the neural mechanism underlying plasticity changes and may provide beneficial information related to motor learning and neurorehabilitation.

An exaggerated blood pressure response to exercise is a risk factor for cardiovascular disease. To test whether combined aerobic and low-intensity resistance exercise training （cross-training） decreases blood pressure during resistance exercise, 43 healthy older individuals participated in a 6-week program as a part of the cross-training group （3 times a week: walking, 60-75% maximal heart rate and 30 min and 4 resistance exercises using one&apos;s body weight, 8-10 repetitions and 2-3 sets） or the control group （asked not to modify their lifestyle during the experimental period）．The cross-training intervention decreased systolic blood pressure （SBP） during a one-hand arm curl exercise at 20% and 40% of one-repetition maximum. In addition, decreases in exercise SBP during the experimental period were greater in the training group versus the control group. These results suggest that combined aerobic and low-intensity resistance training decreases blood pressure during resistance exercise.

As a body temperature lowering mechanism, we have a perspiration function. Recently, we have developed and demonstrated “self-perspiration with evaporative cooling garment” that lowers body temperature by spontaneous “perspiration” and evaporation. The system is cooling the body with both the “water cooling” in which the cooling water flows through the tube on the clothing surface and the “evaporation” in which water is leached from the pores in the tube and evaporated to cool.

In the present study, we developed the leaching by capillary action （capillary type） rather than the leaching by pore water pressure （pore type）， and compared the body cooling function. Six healthy subjects were volunteered to exercise 30W, 60W, 90W, and 120W for 3 minutes each using a cycle ergometer, and changes in skin temperature and humidity in clothing were measured and analyzed simultaneously. The skin temperature decreased with time in both the pore type and capillary type, but the decrease was significantly larger in the capillary type. There was no significant difference in the humidity change in the garment. The capillary type obtained a higher cooling effect without further increasing the humidity in the garment.

One-third of the Japanese is dissatisfied with the quality of sleep. One of the factors that hinder the quality of sleep depth is the influence of temperature and humidity in-bed, which rises due to body temperature during bedtime. The purpose of this study was to investigate indoor temperature/humidity that provides a comfortable in-bed environment and was to investigate sleep quality between regular polyester （RP） and weaken acid polyester （WP） of sleepwear. A pilot study was conducted in 10 healthy volunteers who recruited students at the Matsumoto University. Temperature/humidity in-bed was measured using portable temperature and humidity data logger. Three-room temperature （10, 20, 30℃） and two fabric （feather, cotton） were conducted.

Another study was conducted in 3 patients who complained of skin itching. Participants with a finger ring sleep monitor put on RP or WP during in bed. Sleep quality was assessed using the OSA sleep inventory MA version （OSA-MA）， the Japanese version of the Athens Insomnia Scale （AIS）， the itch VAS score during nighttime.

There was no difference in the time to reach 31℃ in the bed among three room temperature. At the wrists and ankles of more than 50% of participants, the temperature in the bed did not exceed 31℃．Relative humidity showed less than 45% after 30 min in the participants. Dryness condition considered inducible itching to human skin.

There was no difference between RP and WP of sleepwear in OSA-MA, AIS, VAS and sleep depth, however, individual cases seemed to be improved in the WP.

Thus, WP of sleepwear might improve sleep quality during bedtime.

This study mainly aimed to elucidate whether differences in training intensity affect increase in maximal inspiratory mouth pressure （PImax） after 6 weeks inspiratory muscle resistive training. Twenty-four collegiate swimmers were divided into a control group （n=8）， a 50% training group （n=8）， and a 75% training group （n=8）． Two training groups performed maximal inspiration exercise at load resistance of 50% and 75% of individual PImax, respectively. This exercise was performed 30 times per session, 2 sessions per day, 6 days per week for 6 weeks. Before and after the intervention, PImax and time trial of 50 m free-style swimming were measured. PImax were significantly increased in all groups, and relative changes in PImax were not different among groups. 50 m free-style performance was not changed before and after 6 weeks in all groups. These results demonstrated that training intensity did not influence on the magnitude of increased PImax after inspiratory muscle resistive training and increase in PImax did not affect swimming performance in sub-elite swimmers.

We developed a periodic pressure-controlling system to mimic a hypobaric hypoxic environment in a chamber. The characteristics of this system varied between decreased pressure at an altitude of 1,500 m for 180 seconds and increased pressure at an altitude of 0 m for 180 seconds. The present study aimed to determine the relationship between exercise in the periodic hypobaric hypoxic environment （PHHE） and physiological responses evaluated using an oral glucose tolerance test. This study included 2 groups of 13 （Experiment 1） and 8 （Experiment 2） healthy men, who provided written informed consent for participation in the study. All subjects performed an oral glucose tolerance test for 120 minutes and two exercise tests: endurance exercise （Experiment 1） and calisthenics （Experiment 2）．The endurance exercise test consisted of 40% maximal oxygen intake for 18 minutes. The calisthenics test included performance of 3 sets of squat exercises （10 squats/set）．We established three experimental conditions: exercise in PHHE system （periodic condition），at an altitude of 750 m （fixed condition），and at an altitude of 0 m （control condition）．In the periodic condition, the atmospheric pressure was changed periodically from 967 to 817 hPa （external pressure was 1,008 hPa）．In the fixed condition, the atmospheric pressure was fixed at 892 hPa. In the control condition, the atmospheric pressure was fixed at 1,008 hPa. Pulse rate （PR），systolic （SBP） and diastolic blood pressure （DBP），arterial oxygen saturation （SpO2），and blood glucose values were measured during the oral glucose tolerance test. Heart rate, SpO2, and the rating of perceived exertion （RPE） were measured during exercise in experiment 1. SpO2 was significantly lower in the periodic condition. PR, SBP, and DBP were significantly different among the 3 conditions. There were no significant differences in blood glucose values among the 3 conditions. During exercise, HR and RPE were not significantly different among the 3 conditions. In conclusion, glucose metabolism was not suppressed by exercise in the PHHE.

Chronic kidney disease （CKD） is a worldwide health burden that afflicts approximately 10,000,000 people even only in Japan. The unsolved issues around CKD lie not only in high, mainly cardiovascular, mortality of patients with end stage kidney disease but also in substantial expenditure for maintenance dialysis therapy. Unfortunately, effective remedies against CKD have not been well established although recent clinical trials casted light on several pharmaceutical agents for diabetes and hypertension such as renin-angiotensin-aldosterone （RAA） system inhibitors and sodium/glucose cotransporter 2 （SGLT-2） inhibitors. Since aerobatic exercise benefit on CKD progression is controversial, we designed animal experiments in which two different, immunologic and metabolic, renal injury models were conducted to mice which were concurrently subject to treadmill running test for 1 hour per day, 5 times per week. First, the exercise for 1 week prior to disease induction had no effect on albuminuria 8 hours after the induction, of mice with acute passive nephrotoxic serum induced glomerulonephritis. Secondly, we focused on diet-dependent renal injury and confirmed that high fat diet for only 8 weeks conferred to a significant amount of albuminuria in mice. Interestingly, the treadmill test for 8 weeks reduced albuminuria in mice fed with high fat diet as well as suppression of body weight gain. This result indicating that metabolic disorder based renal damage more than immunological renal damage may be able to receive benefits of the aerobatic exercise, raises a possibility that aerobatic exercise may prevent dyslipidemia-mediated CKD progression in a clinical setting. As to mechanistic process, in addition to improvement of systemic lipid and diabetic profile by skeletal activity, mitigation of renal lipotoxicity or enhancement of myokine action may also be contributory. Further study is needed to elucidate the underlying mechanism of the exercise effect on different animal CKD models.

Severe head and neck injuries occasionally occur in collision sports such as Judo or Rugby football. Degenerative changes in the cervical spine including abnormal alignment, spur formation and disc space narrowing are risk factors for severe injuries. It is also well known that neck muscle strength is one of the important factors for the prevention of severe injuries and degenerative disorders. The aim of this study future was to assess the relationship between the neck muscle strength and radiographic findings of the cervical spine among collision sports players. We hypothesized that poor muscle strength and unbalanced neck muscle flexion/extension strength ratio maybe associated with degenerative cervical findings. 168 judo-players （22-32 years old） and 203 rugby football-players （18-30） underwent neck extension and flexion muscle strength measurement, and 55 judo-players and 58 rugby players underwent cervical radiographical examination. Cervical alignment was classified as normal, straight, kyphosis, and sigmoid according to the Borden & Rechitman method. Disc space narrowing and spur formation were also measured according to the Kondo method and the Nathan classification. Height, weight, neck flexion and extension strength, flexion/extension ratio of the judo group ware higher than that of the rugby group with stastical significance. However, there were no significant difference of result/weight value （Judo: flexion;2.39N, extension;3.38N. ratio;0.71, Rugby: flexion;2.37, extension; 3.41, ratio; 0.70）．In Judo group, sigmoid deformity group （420±50.2N） showed significantly higher neck extension strength compared with normal group （331.7±48.4N, p<0.05）．At the factor of flexion/extension muscle strength ratio, straight （0.67） and kyphosis （0.63） group showed significantly lower value compared with normal group （0.78. p<0.05） in Judo. In Rugby group, the presence of spur formation group （0.54） showed lesser flexion/extension muscle strength ratio compared with normal group （0.68）， significantly （p<0.05）．Neck muscle strength is one important factor to prevent and reduce the severe neck injury or cervical spine abnormal findings. From this study, not only the value of muscle strength, but also the flexion/extension ratio provide important contribution for these findings. Lower flexion/extension neck muscle strength ratio is one of the risk factors of cervical spine issues for collision sports players.

Effect of glucose starvation-induced proteolysis on protein translation initiation in response to glucose restoration was examined in C2C12 myotubes. C2C12 cells were cultured in differentiation medium （DMEM containing 2% horse serum and 25 mM glucose） for 4 days. Differentiated C2C12 cells were further cultured in differentiation medium （HG） or in differentiation medium without glucose （NG） for 24h. Glucose （final concentration at 5.5 mM） was added to the both groups, and cells were collected after 30 min of incubation. The phosphorylation level of p70 S6 kinase （p70S6K）， which is the marker for protein translation initiation, was significantly decreased by glucose starvation for 24h. Addition of glucose markedly increased the phosphorylation of p70S6K only in NG group and this phosphorylation level was significantly greater than in HG group. Inhibition of autophagy by bafilomycin A1 diminished the effect of glucose restoration on the phosphorylation of p70S6K. On the other hand, inhibition of ubiquitin-proteasome activity by MG132 did not affect the phosphorylation of p70S6K in response to glucose restoration. In conclusion, glucose starvation-induced autophagy partially account on the activation of translation initiation by glucose restoration.

We investigated the effects of estrogen on AQP4 and NKCC1 in the skeletal muscle by using estrogen-deficient animals following resistance exercise training. Female adult rats （10 weeks old） were divided into the following 6 groups: sham sedentary, sham climbing training, ovariectomy sedentary, ovariectomy climbing training, ovariectomy plus estrogen treatment sedentary, and ovariectomy plus estrogen treatment climbing training groups. The estrogen deficiency is caused by the ovariectomy. After 8 weeks of climbing training, the weight of the flexor halluces longus （FHL） muscles were significantly increased in the sham climbing training group but not in in the ovariectomy climbing training group. On the contrary, ovariectomy plus estrogen treatment resulted in exercise-induced muscle hypertrophy. AQP4 and NKCC1 protein expressions tended to be decreased after ovariectomy, and the estrogen treatment reversed this decrease of AQP4 and NKCC1 in ovariectomized animals. Nevertheless, these differences regarding protein expression among the groups were not significant. Therefore, these data suggest that estrogen regulated exercise-induced muscle hypertrophy but did not affect the expressions of AQP4 and NKCC1 in the skeletal muscle.

The autonomic nervous component obtained from heart rate variability can potentially be used to estimate overtraining. However, no method has been established to estimate temporary training fatigue using heart rate variability. We examined whether the autonomic nervous component response for exercise load can estimate temporary training fatigue. Five participants （age: 21.2 ± 0.8 yrs; height: 174.6 ± 2.5 cm; weight: 62.5 ± 6.0 kg; maximal oxygen uptake [V･O₂max]: 44.5 ± 5.8 ml/kg/min） completed sprint training for 5 days at 70% of each participant’s maximum sprint speed. Heart rate variability was measured during exercise load at the lactate threshold for 5 min using an electrocardiogram before and after training for 5 days. Heart rate variability was automatically translated into the autonomic nervous component using automatic frequency analysis （low-frequency power [LF], high-frequency power [HF], LF/HF）．Feelings of fatigue were measured using the Visual Analogue Scale （VAS） after exercise load before and after sprint training for 5 days. Feelings of fatigue after exercise load increased after training compared with that before training （p<0.05）．Moreover, feeling fatigued was correlated with a decreased LF component during exercise load （reflecting sympathetic nervous and parasympathetic nervous activities; r=-0.988, p<0.05）．HF （parasympathetic nervous activity） and LF/HF （sympathetic nervous activity） during exercise load were not correlated with feeling fatigued after exercise load （HF: r=-0.082, p=0.895; LF/HF: r=-0.424, p=0.477）．The autonomic nervous component （LF） response for exercise load can potentially be used to estimate temporary training fatigue.

The triceps brachii long head （TBL） is a biarticular muscle that crosses the shoulder and elbow joints, and therefore its length is influenced by the position （angle） of each of these two joints. With this background of the biarticular nature of the TBL, this study examined the effect of muscle length during resistance training on muscle hypertrophy, by comparing two elbow extension training regimes performed at different, otherwise identical, shoulder joint positions. Using a cable machine, 21 healthy young adults conducted dynamic elbow extension （range of motion: 90-0ﾟ） training, with the shoulder joint of one side fixed at 180ﾟ flexion and the other at 0ﾟ （i.e. the elbow facing upwards and downwards, respectively）， whereby the TBL was in a long （L） and short （S） length condition, respectively. The training was performed with the load of 70% of one-repetition maximum, 10 reps/set, 5 sets/session, 2 sessions/week, for 12 weeks. After the intervention, MRI-based cross-sectional area （CSA） of the total triceps brachii （the sum of the three muscles） significantly increased in both conditions, with a greater degree for the L （23%） than S （16%）．On an individual muscle basis, the CSA significantly increased in all muscles for both conditions, with a significant difference in the degree between conditions only found in the TBL （L: 33% vs S: 21%） and not in the other two （monoarticular） muscles. These results suggest that the muscle hypertrophic effect of resistance training can be enhanced by conducting training at a long muscle length position.

Excessive co-contraction interferes with smooth joint movement via mechanisms including failed spinal reciprocal inhibition against antagonists. However, the function of spinal reciprocal inhibition during co-contraction remains unclear. To investigate the influence of changes in contraction intensity during co-contraction on spinal reciprocal inhibition, 20 healthy adults were subjected to four stimulation conditions: a conditioning stimulus?test stimulation interval （CTI） of −2, 2, or 20 ms or a test stimulus without a conditioning stimulus （single）．Co-contraction （change in soleus muscle [Sol] vs. tibialis anterior [TA] activity） was examined at task A 0% vs. 0% maximal voluntary contraction （MVC）， task B 5% vs. 5% MVC, task C 15% vs. 15% MVC, task D 5% vs. 15% MVC, and task E 15% vs. 5% MVC.At CTI of 2 ms, the H-reflex amplitude value was significantly lower in tasks A, B, C, and D than in the single condition. Among the tasks, the H-reflex amplitude values were lower for A, B, C, and D than for E. At CTI of 20 ms, the H-reflex amplitude was significantly lower in tasks A, B, C, D, and E. Among the tasks, the H-reflex amplitude was significantly lower from task A and B to task E. For co-contraction <15% MVC, reciprocal Ia inhibition may be modulated depending on the Sol vs. TA muscle activity ratio. D1 inhibition was equivalent when the Sol/TA ratio was equal or TA muscle activity was high. During co-contraction with high Sol muscle activity, D1 inhibition decreased from rest but D1 inhibition remained.

The current study investigated the relationships between muscle cross-sectional areas of trunk muscles and dynamic balance ability in the sitting position for 14 healthy young men in order to obtain knowledge about improvement of performance in sit-ski. The cross-sectional images of the erector spinae muscle, the abdominal rectus muscle and the abdominal internal-external oblique muscles were obtained by extended field-of-view ultrasound imaging. Their cross-sectional areas were determined using ImageJ. To evaluate the dynamic balance ability in the sitting position, a floor reaction force meter was fixed on a six-axis motion base used as a disturbance applier, and a chair ski seat was placed on it. Participants sat on the seat, and the following disturbances were applied: 1） disturbances to move the basal plane laterally, 2） disturbances to tilt the basal plane, and 3） disturbances to add both simultaneously. Because the dominant arm of all participants was the right arm, the laterality was first confirmed for all parameters. As a result, there was no laterality in each parameter. When investigating the relationships between the muscle cross-sectional areas of each muscle and the dynamic balance ability in the sitting position, therefore, the left and right mean values were used. There was a significant correlation between the muscle cross-sectional area of the abdominal rectus muscle and the dynamic balance ability. On the other hand, the muscle cross-sectional area of the abdominal rectus muscle was smaller than the others. Consequently, it could not be asserted that the amount of the muscle cross-sectional area of the trunk muscle affects the dynamic balance ability in the sitting position positively.

Regular exercise improves capillary density （capillary network） in skeletal muscle, which contributes to protect against chronic diseases- or aging-induced skeletal muscle atrophy. Although capillary density in skeletal is likely to be regulated by multiple angiogenic factors from skeletal muscle, the exercise-induced angiogenic factor family are poorly understood. In this study, we measured angiogenic factors in skeletal muscle to identify a family of angiogenic factors that regulate capillary density by regular exercise. To identify multiple angiogenic factors, we compared the factors between oxidative soleus muscle with high capillary density and glycolytic extensor digitorum longus muscle with low capillary density. We also compared angiogenic factors between exercise training group and sedentary group in plantaris muscle. After the analysis, we combined these results to identify family for exercise-induced angiogenic factors. Thirty-four angiogenic factors in oxidative soleus muscle were higher than glycolytic muscle. Forty-one angiogenic factors in exercise training group were higher than sedentary group. Twenty-seven an angiogenic factors were abundant in both oxidative muscle and exercise group. These results suggest that the multiple angiogenic factors could be a potential role to regulate capillary density by exercise training.

Individuals with limb amputations appear to benefit both physically and psychologically from participation in sports and/or regular physical activity, leading to a healthy lifestyle. However, individuals with unilateral transfemoral amputations （UTFA） have difficulties in preventing falls due to prosthetic knee buckling, defined as the sudden loss of postural support during weight-bearing activities. Despite the risk of prosthetic knee buckling can be evaluated by the prosthetic knee angular impulse （PKAI） during the stance phase, little is known about the factors associated with PKAI in individuals with UTFA. Therefore, the aim of this study was to investigate the demographic factors associated with prosthetic knee buckling risk in runners with UTFA. Fourteen participants with UTFA performed running on a 40-m of runway, where seven force platforms and optical motion capture cameras. We quantified the risk of knee buckling as prosthetic external knee flexion angular impulse, which is the time integral of external knee flexion moment during the stance phase of prosthetic limb. We used the Pearson&apos;s correlation coefficients to examine the relationship between the demographic data and risk of knee buckling. Only the body mass and body height had the significant negative correlation with the risk of knee buckling. These results suggest that unilateral transfemoral amputees with a smaller body height and body mass may be exposed to a higher risk of prosthetic knee buckling during running.

Individuals with limb amputations appear to benefit both physically and psychologically from participation in sports and/or regular physical activity, leading to a healthy lifestyle. However, individuals with unilateral transfemoral amputations （UTFA） have difficulties in preventing falls due to prosthetic knee buckling, defined as the sudden loss of postural support during weight-bearing activities. Despite the risk of prosthetic knee buckling can be evaluated by the prosthetic knee angular impulse （PKAI） during the stance phase, little is known about the factors associated with PKAI in individuals with UTFA. Therefore, the aim of this study was to investigate the demographic factors associated with prosthetic knee buckling risk in runners with UTFA. Fourteen participants with UTFA performed running on a 40-m of runway, where seven force platforms and optical motion capture cameras. We quantified the risk of knee buckling as prosthetic external knee flexion angular impulse, which is the time integral of external knee flexion moment during the stance phase of prosthetic limb. We used the Pearson&apos;s correlation coefficients to examine the relationship between the demographic data and risk of knee buckling. Only the body mass and body height had the significant negative correlation with the risk of knee buckling. These results suggest that unilateral transfemoral amputees with a smaller body height and body mass may be exposed to a higher risk of prosthetic knee buckling during running.

The purpose of this study was to test if lung volume during swimming can be estimated from optical motion capture system. To achieve this goal, we tried to develop a digital human model expressing respiratory motion. A male swimmer performed lung function tests during the quiet standing and tethered front crawl swimming under the water, and respiratory flow rate and three-dimensional （3D） motion data were measured synchronously. Respiratory flow rate was integrated to obtain lung volume （measured lung volume） as a function of time. 3D motion data of trunk segment was collected by an underwater motion capture system. 3D shape data of the whole body was scanned for the swimmer on dryland. Digital human model expressing respiratory motion was created based on the 3D shape data. Then, digital human model was fitted to 3D motion data by using inverse kinematics computation, and lung volume was estimated from the change in volume of the model （estimated lung volume）．Measured and estimated lung volume were compared by using the Intra-class correlation coefficient （ICC）．As a result, ICCs during standing were 0.981 for quiet breathing, 0.995 for force vital capacity, and 0.972 for maximal voluntary ventilation （P < 0.001）．On the other hand, ICC was smaller during swimming compared with values during standing, with being 0.717 （P < 0.001）．These results suggest that our digital human model with motion capture data under the water can accurately estimate lung volume at least in lung function tests during standing. Further study is needed to improve our digital human model to estimate lung volume more accuracy during swimming.

In this study, to develop a simple and practical cooling method for hot environments, a vest was designed by incorporating a highly absorbent batting material and a moisture-permeable and waterproof fabric as the cover fabric. The authors have named this vest as the “cooling vest.” Three types of clothing styles were examined: T-shirts （sample T）， T-shirts and a jacket with two small fans （sample TA）， and T-shirts, the cooling vest, and a jacket with two small fans （sample TVA）．Five female subjects aged 21-27 years were engaged for the study. The experiments were performed in an environment having a temperature of 32℃．Following parameters were measured through the wearing experiments: sweating rate, clothing temperature and humidity, oral temperature, skin temperature, and heart rate. Obtained results indicate that compared to the other samples, skin temperature, clothing temperature, and sweating rate tend to be lower in the case of sample TVA. The effect of sample TVA on heart rate and oral temperature could not be observed because the duration of wearing time was very short （15 min）．Additionally, subjective evaluation suggests that sample TVA is comfortable to wear and feels cool. These results can be attributed to the release of water vapor from the cooling vest and enhanced evaporation caused by the fans. Furthermore, while conducting the wearing experiments, clothing humidity increased owing to the evaporation of water vapor from the cooling vest, but the corresponding evaluation score for humid sensation didn&apos;t decrease. Hence, it can be concluded that by employing the cooling vest along with a jacket having fans, the loss of latent heat can be increased without causing excessive sweating.

In the present study, to clear the possibility of glycation stress as an exercise-resistance factor, we investigated the effect of glycation stress on the molecules related to glucose metabolism and mitochondrial functions following to endurance exercise training in mice and on muscle power changes following resistance training in human. Four-week voluntary exercise training increased the expression levels of GLUT4, PGC1α, and HSP72 in mouse plantaris muscle. On the other hand, these changes were suppressed by the concomitant treatment of methylglyoxal, an inducer of glycation stress. In young male adults, the group in high-glycation stress showed lower leg muscle power output than that in low-glycation stress, but there was no difference between the two groups in the strength-enhancing effect of 12-week resistance training. In conclusion, it is suggested that glycation stress suppresses skeletal muscle adaptations induced by endurance exercise training and does not affect muscle power enhancement induced by resistance training.

In this study, we investigated the ability to adjust grip strength in childhood by comparing the characteristics of force generation and relaxation. Twenty-six boys and twenty-five girls in fifth grade （11 years old） performed their strongest grip [maximum voluntary contraction （MVC） task］．adjusted from complete relaxation to their self-perceived half strength [generation task （0% MVC to 50% MVC）］．and adjusted from maximum voluntary strength to their self-perceived half strength [relaxation task （100% MVC to 50% MVC）］．Two trials were performed for each task, and the average value was calculated. In addition, during the generation and relaxation tasks, the relative values were calculated based on the 100% MVC, and the constant and absolute errors from the target value （50% MVC） were evaluated. There were no significant relationships in the constant error among the force levels of maximum, generation, and relaxation tasks for boys and girls. The relative values were significantly smaller during the relaxation task than during the generation task and were smaller in girls than in boys. The constant errors were significantly negatively greater during the relaxation task than in the generation task in boys and girls, and greater in girls than in boys during the generation and relaxation tasks. Moreover, there was a positive correlation in the relative values between generation and relaxation in boys. These results suggest that the ability to exert maximum power and adjust power are different, and the ability of force control is higher in boys than in girls during childhood.

Aerobic exercise is an excellent way to maintain good health, and marathons are a popular form of aerobic exercise. It has been suggested the appropriate level of exercise intensity should be evaluated to ensure that athletes newly adopting the sport do not harm themselves. Studies that using spectral analysis of heart rate variability （HRV） to evaluate autonomic nervous activity have established HRV as an indicator of exercise intensity. HRV is analyzed in terms of four distinct frequency bands of spectral power: ultra low （ULF）， very low （VF）， low （LF）， and high （HF） frequencies. Evidence suggests that the HF band reflects parasympathetic activity and the LF band reflects sympathetic activity. Thus, the LF/HF ratio reflects sympathovagal balance. This study evaluated two male pacesetter marathon runners wearing ECG leads monitored during a 30-km marathon in Japan. Time series data of the runners’ R-R intervals over 90 min was analyzed with a method of time series analysis based on maximum entropy method. The result obtained showed that the spectral power values in ULF and VLF bands exceeded those in LF and HF bands. Others have reported that ULF and VLF power values decrease as cardiovascular disease severity increases. Accordingly, these values all have clinical prognostic potential for the evaluation of individuals&apos; capacity for exercise.

Generally, it is said that the polymer materials degradation is caused via a radical species by factors such as heat and light, oxygen, the mechanical stress. However, it has been very rare that the reaction intermediates were observed under a real condition so far. The indicated reaction schemes were actually determined inductively from the results of the product analysis after the reaction.

In this study, the thermo-mechanical degradation of the saturated hydrocarbon polyurethane was investigated using a Spin-Trapping Method, which prolongs the life time of the radical species long enough to be measured by common electron spin resonance （ESR） measurement. If the spin adduct by spin-trapping was detected by ESR, the molecular structure of the original radical can be assigned from the ESR spectrum of spin adduct. As a result, the milled polyurethane did not show any kinds of radical signals by ESR. It was thought that the enough stress was not applied on the main chain due to its low molecular weight. On the other hand, on heating between 140 ℃ and 180 ℃， five spin adducts were successfully observed by ESR. Those spin adducts were derived from ･OCH2- and ･CONH- radicals produced by dissociation of urethane O-CONH bonding, as well as -･CH- radical produced by dehydrogenation on the main chain CH2 and ･CH2- radical produced by β-scission on the main chain. Using spin-trapping method, we could clarify that the radical reactions occur on the thermal degradation of polyurethane, which had not been known until now, and show the usefulness of the spin-trapping method for the investigation of degradation analysis of polymer materials

Rowing has a unique exercise characteristic, that is, moving body toward back and forth to generate power output, and the work for that kind of movement was not considered when predicting energy expenditure. The aim of this study was to evaluate aerobic and anaerobic energy supplies during 2000 m rowing test with using a newly developed accumulated oxygen deficit （AOD） method which takes the exercise characteristic of rowing into account. Thirteen male university rowers conducted 2000 m test. In each 250-m section, utilized anaerobic energy was determined by subtracting measured oxygen uptake from predicted oxygen demand which was predicted by power output and accelerometer output measured by rowing ergometer and tri-accelerometer sensor being put on rower&apos;s back, respectively. The highest sectional anaerobic energy utilization was observed at the first section, then sectional anaerobic energy utilization gradually decreased with time course, however, contribution of anaerobic metabolism maintained around 10 % during second half of the test. Although entire contribution of anaerobic metabolism reached 18.3 ± 6.2 %, total amount of anaerobic energy was not correlated with average power output of 2000 m test （r = -0.15, p = 0.625）， however, maximal oxygen uptake was （r = 0.83, p = 0.001）．The highest sectional power output was observed at the first section and gradually decreased with time course, meanwhile, power output at the final section was not significantly different from its previous section. Amount of available anaerobic energy at the final section and the second from final section were significantly correlated with relative power output at the final section （r = 0.66, p = 0.015 and r = 0.57, p = 0.04）．These results suggested that rowing performance is mainly related to aerobic ability as reported previously, and anaerobic capacity would be important to maintain higher power output during second half of the test and especially at the final section.

It is crucial to establish the strategies that prevent the development of lifestyle diseases including cardiovascular disease. It is well known that exercise training including endurance training is beneficial for prevention or treatment of cardiovascular disease. However, its molecular mechanism is incompletely understood. Accumulating evidence indicates that skeletal muscle produces various bioactive secretory molecules, also known as myokines, which can affect the pathogenesis of cardiovascular disease. Here, we sought to identify the myokine that is regulated by endurance exercise and investigate its role in the development of cardiovascular disease. After screening of gene expression profiles and predicted secretory proteins in skeletal muscle in sedentary versus treadmill exercised mice, we found that myonectin was a myokine that was upregulated by treadmill exercise. Myonectin protected the heart from ischemia-reperfusion injury. Myonectin reduced apoptotic activity and inflammatory response in cultured cardiac myocytes. These data suggest that myonectin acts as an exercise-induced myokine that has protective effects on heart disease.

Purpose: To clarify the characteristics of physique, static posture, and shoulder range of motion in Japanese elite para swimming athletes with unilateral congenital upper limb deficiency.

Method: Participants were six Japanese elite para-swimming athletes with unilateral congenital upper limb deficiency. Height, body mass, upper arm length, forearm length, maximum brachial circumference, shoulder range of motion, inter-elbow distance, shoulder rotary distance, heel-buttock distance and stream line posture were evaluated. The shoulder range of motion was compared to the general normal range of motion, and asymmetry was confirmed by an existence of side to side difference. Streamline posture of each participant was qualitatively evaluated.Result: Since the range of motion in flexion was restricted in five participants and internal rotation in the deficient limb were more restricted in all participants as well as extension and external rotation in five subjects than the sound side, side to side difference was observed. Inter-elbow distance which reflects flexibility of the shoulder complex was greater when deficient limb was at the upper side in all participants. Excessive lumber extension in three participants and inadequate shoulder flexion in the streamline position were observed in five participants.Conclusion: Physical characteristics of Japanese elite para swimming athletes with unilateral congenital upper limb deficiency is represented the restricted range of motion in shoulder flexion and internal rotation of the deficient limb. Educational physiotherapy intervention may be required to gain ideal streamline posture, to increase propulsion force, and to prevent swimmer&apos;s shoulder.

Overtraining is primarily related to chronic stress caused by sustained high load training, and often coupled with other stressors. However, a diagnostic tool that monitors chronic stress has yet to be developed. Recently, hair cortisol concentrations （HCC） has been increasingly gaining attention as a novel biomarker of chronic stress, and we hypothesize that HCC could be a useful biomarker for preventing overtraining. To determine this hypothesis, we investigate the relationships between HCC and aerobic performance such as the peak oxygen uptake （V･O2peak） and oxygen transport ability for 41 young male adults （Age: 19.7±1.5yr, Height: 171.7±5.2cm, Weight: 58.2±5.3kg）．HCC, blood cortisol, red blood cells （RBC）， hemoglobin concentrations （Hb）， were measured once per month at June and July. 27 subjects without big sports events in June and July measured V･O2peak. HCC was measured by the enzyme-linked immunosorbent assay （ELISA） in the most proximal 1cm of hair. The results showed that HCC and V･O2peak increased in July. Although, there was no significant negative correlation between HCC and V･O2peak, there were significant negative correlation between HCC and RBC （June: r=-0.309, p<0.05; July: r=-0.384, p<0.05）．Moreover, there were significant negative correlation between HCC and The POMS category vigor in July （r=-0.341, P<0.05） .These results suggest that HCC associated with declining oxygen transport ability and mood. Chronic stress of athletes may cause declining endurance performance and mood and as a result may be related to overtraining syndrome.

Our study aimed to investigate to elucidation of the pathogenic mechanism of plantar fasciitis in pes planus by using plantar fascia model. We recruited healthy 13 males in normal foot and healthy 13 males in pes planus. Foot alignment was categorized using foot posture index. Participants ran at self-selected speed. Plantar fascia model was used to calculate tension of plantar fascia was calculated using As results, running speed was not significantly different between normal foot and pes planus （p = 0.63）．Additionally, peak in tension of plantar fascia were not significantly different between normal foot （25.5±5.3N/kg） and pes planus （27.1±5.9N/kg, p = 0.40）．Previous study has suggested that tension of plantar fascia increases in pes planus. However, this study showed that tension plantar fascia in pes planus does not increase compared with normal foot.

Athletes with unilateral transfemoral amputation use mechanical prosthetic knee joint and running-specific prosthesis for their affected leg. Previous studies reported that athletes with unilateral transfemoral amputation adopt the specific sprint techniques to obtain the speed due to their asymmetric legs. Adaptation of champion’s techniques is known as one of the useful strategies for improvement of performance. The present study, therefore, aimed to examine the Paralympic champion specific technique for obtaining the great sprint speed by using the deterministic model. A Paralympic champion with unilateral transfemoral amputation and corresponding six Japanese athletes were asked to run on runway with their maximal speed. Each mechanical parameter in the deterministic model of the sprint speed was compared between a Paralympic champion and Japanese athletes. As the results, a Paralympic champion exerted the small vertical component of the ground reaction force per body mass, and this induced the short flight time of the intact leg. This resulted in the great sprint speed of a Paralympic champion.

Prevention of mobility loss due to aging is critical to avoid or postpone the necessity for continuous care in late stages of life. In particular, knee extensors have a key role in maintaining balance and stabilizing gait. As loss of muscle strength in knee extensors jeopardize mobility abilities, continuous training of these muscles is fundamental.

Walking is the most popular daily exercise. However, the training effects of simple walking are limited to lower leg muscles and are not sufficient to prevent progressive deterioration of knee extension muscle strength if not integrated with specific exercises targeting those muscles. Therefore, we are working on the development of a training device to apply additional mechanical load on the knee during walking and extend the training effect of simple walking to knee extensors. The training device will be designed for maximum versatility using a compact oil damper with no need for electrical power. The specifications of the device will be determined using results from preliminary research on knee extensor muscle activity during walking, evaluated with an IMU （Inertial Measurement Unit） based measuring system. In this study, we designed a prototype of the device and evaluated if the device could induce sufficient muscle activity in the knee extensor muscle. In the future, we are planning to replace the oil damper with an active actuator and integrate the measuring system in the device to allow adaptive training load depending on real-time measured knee extensor muscle activity.

Introduction: The current exercise prescription, defined by a cardiopulmonary test （CPX） for patients with cardiovascular disease, makes it difficult to offer an appropriate aerobic exercise in accordance with the patients’ daily conditions. Heart rate variability （HRV） is the beat-to-beat alterations in heart rate, which reflects the cardiac autonomic nervous activity. Therefore, we examined whether real-time analysis of HRV makes it possible to determine the ventilatory threshold during cardiac rehabilitation sessions.

Methods: A total of 25 patients （66±8 y/o, 22 males） with heart failure who underwent cardiac rehabilitation on a bicycle ergometer for 25 minutes were enrolled. The oxygen uptake （VO₂） and high-frequency component （HF） quantified by the power spectral analysis of HRV reflecting the parasympathetic nervous tone, were continuously measured during the rehabilitation session. The workload was adjusted every 2 minutes so that the HF power was kept between 5 and 10. All the patients had undergone a CPX session within a week before their ventilatory threshold （VT） -VO₂ determination and had the exercise intensity prescribed. We compared the VO₂ during the rehabilitation session （re-VO₂） to the VT-VO2 determined by the CPX.

Results: The re-VO₂ reached to 95.3±12.0% （13th minute after the initiation of the exercise session） , 100.7±17.3% （17th min） , 101.5±18.0% （21th min） , and 97.7±18.3% （25th min） of the level of VT-VO2 in the second half of the exercise. The mean differences between the re-VO2 and the VT-VO₂ were not statistically significant at any time point.

Conclusions: Real-time assessment of the HRV during rehabilitation could offer exercise intensity of the ventilator threshold in accordance with the condition of patients with cardiovascular diseases.