In downhill alpine skiing, racers often exceed speeds of 120 km/h, with air resistance substantially affecting the overall race times. To date, studies on air resistance in alpine skiing have used wind tunnels and actual skiers to examine the relationship between the gliding posture and magnitude of drag, as well as for the design of skiing equipment. However, these studies have not revealed the flow velocity distribution and vortex structure around the skier. In the present study, we used computational fluid dynamics with the lattice Boltzmann method to derive the relationship between flow velocity in the full tuck position （the downhill racer & apos ; s speed） and total drag. Furthermore, we visualized the flow around the downhill racer and examined its vortex structure. The results show that the total drag force in the downhill racer model is 27.0 N at a flow velocity of 15 m/s, increasing to 185.8 N at 40 m/s. Moreover, the visualization of the flow field indicates that the primary drag locations at a flow velocity of 40 m/s are the head, upper arms, lower legs, and thighs （including the buttocks）.

Sportswear made of polyester has an odor problem due to the absorption of sweat odorous substances which could not be removed by washing. Some bacteria such as Staphylococcus aureus are normally present on human skin. When sweated, malodorous smell is generated due to the decomposition of sweat by bacteria. When the skin pH is increased from weakly acidic to alkaline side due to perspiration, Staphylococcus aureus will grow and cause not only odor but also itching and eczema on skin. Thus if a sportswear could maintain skin pH weakly acidic during sweating, the activity of Staphylococcus aureus could be suppressed and reduce malodor. In this study, we prepared weak-acidic polyester fiber by processing polyester fiber with malic acid or acetic acid, and the fabric made of this weak-acidic polyester fiber was evaluated in terms of the deodorant/antibacterial properties and the effect on skin. Two types of weak-acidic polyester fibers were tested on skin, and confirmed that polyester processed with malic acid （weak-acidic polyester） has no adversely effect on skin. The skin pH was found to be kept weak-acidic even after hard perspiration when a subject put on a T-shirt made of weak-acidic polyester. The weak-acidic polyester has high antibacterial property against Staphylococcus aureus, and high deodorant effect against ammonia, a model malodor of sweat..

In the present study, we investigated the effects of exercise on human cognitive processing under different thermal conditions （20 ℃ and 35 ℃ conditions）． Eleven healthy males performed 4 × 15-min bouts of cycling exercise Event-related potentials （ERPs） were recorded in five sessions during somatosensory Go/No-go paradigms （i.e., pre, post-1st exercise bout, post-2nd exercise bout, post-3rd exercise bout, and post-4th exercise bout）． As thermoregulatory and hemodynamic variables, the external ear canal temperature, mean skin temperature, heart rate, and mean arterial blood pressure were recorded. The reaction time and error rates were not affected by the repetition of aerobic exercise or different thermal conditions. However, the peak amplitude of the N140 component, which was mainly related to somatosensory processing, was significantly reduced with the repetition of cycling exercise, and the decrease was marked in No-go trials under 35 ℃ condition. Moreover, the peak amplitude of P300, which was linked to the cognitive processes of context updating, context closure, and event-categorization, was significantly smaller in the post-3rd and post-4th exercise bouts under 35 ℃ than under 20 ℃ condition. These results suggest that executive function, which was based on reaction time and error rates, would not be affected by the repetition of aerobic exercise and different thermal conditions, but aerobic exercise under higher thermal conditions may impair human cognitive processing..

Type 1 diabetes patients often suffered from exercise-induced hypoglycemia especially, nocturnal and delayed onset of hypoglycemia after exercise. In the present study, we characterized potential mechanisms for the development of delayed onset of exercise-induced hypoglycemia in type 1 diabetes by performing animal studies. We assessed the blood glucose levels and glucose metabolic pathway activation over time in streptozotocin （STZ） injected rats, STZ rats with exercise （STZ+EX），and control rats with exercise （CON+EX）．Moreover, samples were taken at 1h, 3h and 5h after exercise in three groups, and was used for microarray analysis. Although blood glucose levels of STZ rats and CON+EX rats did not differ significantly before and after exercise （0 h to 5 h）， the blood glucose levels of STZ+EX rats were significantly lower than those of STZ group at 3 h （P < 0.05）．In skeletal muscles, Akt phosphorylation level and GLUT4 translocation were significantly increased at 1 h in both CON and STZ groups and were lowered to negligible levels within 3 h. In contrast, in the STZ+EX group, Akt phosphorylation, and GLUT4 translocation was maintained by 5 h, indicating sustained glucose metabolism in STZ+EX group. In microarray analysis, 447 genes of insulin signaling and 79 genes of type 1 diabetes were found in this study, and selected 3 genes which may concern GLUT4 regulation, especially Oncostatin M（Osm） and signal transducer and activator of transcription 3（STAT3） were increased at 3h and 5h after exercise in STZ+EX group. In summary, we showed that a single bout of aerobic exercise induced prolonged enhancement of GLUT4 translocation may be involved in the induction of hypoglycemia.

Patients with upper limb deficiencies have almost no chance that functional artificial arms are prescribed for in Japan. In addition children with upper limb deficiencies face to the participation restrictions at the class of physical education during the elementary education course. On the other hand Crandall RC strongly concluded that unilateral pediatric amputees should be offered a variety of prosthetic options to help with normal activities of daily living. In this report, we evaluated the durability and the quality of the artificial arm terminal device Shroom Tumbler （TRS） which is used in gymnastic competitions in North America, because we considered this terminal device is suitable for use also in Japan. As long as the elementary school students use it when vaulting horse at the class of physical education, we elucidated that this terminal devise possesses sufficient durability that fatigue destruction accompanying use does not occur even if it is used for three years. We provided a child with unilateral upper limb deficiency with the special prosthetic arms which used the Shroom Tumbler as the terminal device, and evaluated them. We considered how the sockets and the liners should be made or selected, how the children should be trained with this prosthetic arms, and whether they are useful or not in actual use.

The aim of this study was to examine the effects of different concentrations of maltodextrin solution （CHO） mouth rinse on endurance exercise capacity, physiological and subjective responses. Nine endurance-trained subjects completed cycling trials at 55% of maximum to complete exhaustion. Mouth rinse was done every 5 min for 10 seconds. CHO concentrations are set for 0%, 6% and 18%. Endurance exercise capacity, physiological indexes （rectal temperature, mean skin temperature, heart rate, cerebral oxidation） and subjective indexes （rating of perceived exertion: RPE, comfort in the mouth） were measured every 5 min. Time to exhaustion with 18% （70.6 ± 6.3 min） was significantly longer than that with 0% （62.1 ± 5.1 min） and 6% （65.9 ± 5.5min）．Physiological indexesand RPE increased during exercise; however these are not significantly different between conditions. These results indicate that high concentration of CHO mouth rinse improves endurance exercise capacity without increase in physiological responses. These results suggested that the increase in exercise performance by CHO mouth rise might be related to the improvement of brain activity during exercise.

To elucidate the effects of age-related decrease in aerobic capacity on the blunted thermal sensation observed in the seniors, we compared thermal sensation between seniors （mean age 69 yrs） and young counterparts （mean age 22 yrs） who have similar maximal oxygen uptake and physical characteristics. Under normothermia and mild-hyperthermia （esophageal temperature, +0.7 - +0.9˚C, lower legs immersion in 42˚C water）, warm and cold detection threshold at the forearm and chest and also whole body thermal sensation （VAS） were determined in addition to thermoregulatory responses. We found that there were no significant differences in esophageal and mean skin temperatures while warm detection threshold at the forearm was significantly higher （blunted） in the seniors than the young. On the other hand, there were no significant differences in warm detection threshold at the chest, cold detection threshold at the forearm and chest, and also whole body thermal sensation between the groups. These results may suggest that age-related decease in aerobic capacity causes the decreased whole body thermal sensation while does not associate with the blunted warm detection threshold at the extremities with normal aging. Thus, the blunted thermal sensation with aging would be improved, at least in part, with the enhanced aerobic capacity in the seniors.

People now concerns about health effect of thermal environments. Clothing is considered as one of major influential factors on thermal environment around human, in this sense, it is important to understand the thermal effects of clothing for establishing better living environments. Considering dynamic thermal environmental changes in outdoor situations, a method for evaluating thermal states of wearers was examined. Since thermal properties have impact on wearers, firstly, thermal conductivity, heat transfer coefficient, and also radiative properties were measured. Then, experimental method for understanding the relations among environments, thermal properties of clothing, human physiology, and human perceptions was carefully considered and used for measurement. Human energy balance is in general a useful tool for expressing thermal states of human, and in this study a method for clothed human energy balance calculation which is applicable to various environments, clothing ensembles, and human physiological states, was newly developed. Under typical outdoor situations such as solar radiation and wind conditions, the clothed human energy balance was verified by comparing experimental results, and proved with satisfactory accuracy. Finally, we provide a suitable way to think about appropriate clothing for given situations, and at the same time the results of the study also provide a database for designing better living environments with clothing.

This study examined whether home-based, high-speed calf-raise training changes the rate of torque development （RTD） of the plantar flexion, balance performance and the resting muscle hardness of the gastrocnemius medialis （MG） in elderly men. Twenty-three healthy elderly men （70–79 yr） were randomly assigned to a training （n = 13; 73.9 ± 2.9 yr） or control group （n = 10; 73.2 ± 3.3 yr）．The subjects in the training group performed 8 weeks （3 times per week） of home-based bilateral calf-raise training using body mass. On the other hand, the subjects in the control group were requested to continue their normal daily activities throughout the same period. The RTD of the plantar flexion, the outer circumferential area of center of pressure （COP） displacement during single-leg standing and the resting MG hardness were measured before and after the intervention. The RTD relative to maximal strength of the plantar flexion was calculated as nRTD. In addition, the muscle volume of the plantar flexors was estimated using the muscle thickness of them and the lower leg length. No variables changed in the control group. In contrast, nRTD of the plantar flexion and the resting MG hardness increased and the outer circumferential area of COP displacement during single-leg standing decreased significantly after the intervention in the training group. Our findings indicate that the calf-raise training at home, performed without special equipment or venue, induces improvements of the rapid force generating capability of the plantar flexors and the ability of balance performance. That is, this training program is useful to maintain and/or improve the quality of life for elderly men. Furthermore, from the perspective of muscle mechanical properties, it is suggested that a stiffer muscle can contribute to the higher rapid force generating capability.

The purpose of the present study was to examine the effect of feeding status before endurance exercise on the incidence of hypoglycemia after pre-exercise ingestion of carbohydrate, and to elucidate the characteristics of individuals with high susceptibility to hypoglycemia after pre-exercise ingestion of carbohydrate. Sixteen subjects performed 60 min cycle ergometer exercises at 75%V･O2max in overnight fasted and fed （3 h after breakfast） states in random order. In both conditions, they consumed 500 ml of a beverage containing 150 g of glucose 30 min before the start of exercise. The criterion of hypoglycemia was set at 70mg/dL. In both conditions, mean plasma glucose levels did not drop below 70mg/dL 15 min after the start of exercise. In the fed state, plasma glucose levels dropped transiently below 70mg/dL in 7 subjects, who showed substantially higher V･O2max, while plasma glucose levels remained above this level in the other subjects. On the other hand, 5 subjects developed transient hypoglycemia in the fasted state and their serum insulin levels at the onset of exercise and insulinogenic index were significantly higher than that in the other subjects who did not demonstrate a decline in plasma glucose. In conclusion, the present study demonstrated that pre-exercise ingestion of carbohydrate 30 min before endurance exercise causes hypoglycemia in several individuals regardless of feeding status. Furthermore, subjects with higher aerobic fitness and enhanced insulin secretory capacity seem to be more prone to hypoglycemia following pre-exercise carbohydrate ingestion under fed and fasted conditions, respectively.

Purpose: This study aimed to examine the effects of electrical stimulation in hypoxia on arterial stiffness and glucose metabolism. Methods: Seven healthy male adults participated in experiments of four different protocols （i.e., rest in normoxia （NR）， rest in hypoxia （HR）， electrical stimulation in normoxia （NES）， and electrical stimulation in hypoxia （HES）） in random order on separate days. Throughout a 40-min measurement, the subjects breathed normoxic （20.9%O2） or hypoxic （15.3 – 15.5%O2） gas via a facemask connected to the oxygen generator. Also, in NES and HES, a 20-min electrical stimulation of 4 Hz was conducted in a lower limb in the latter 20-min of the measurement. Results: During electrical stimulation, heart rate and oxygen uptake in NES and HES increased, compared with each baseline. However, no significant difference was observed in the heart rate between NES and HES. Conversely, oxygen uptake during electrical stimulation was significantly lower in HES than in NES. Interestingly, CAVI, which is an index of arterial stiffness, significantly reduced, and the reduction in CAVI was significantly greater in HES than that in NES. In addition, lactate concentrations and respiratory exchange ratio were significantly higher in HES than the other three trials. Conclusion: These findings suggest that electrical stimulation in hypoxia can induce both greater reduction in arterial stiffness and increase in glucose metabolism than those in normoxia.

Ground reaction force is often used to predict the risk of injuries but may not coincide with the forces applied to commonly injured regions of the foot. This observational study examined the forces applied to the foot and the associated moment arm made by three foot strike patterns. Ten male runners ran barefoot along a 15 m runway at 3.3 m/s using forefoot, midfoot, and rearfoot strikes. Three-dimensional coordinates of markers and ground reaction force were recorded. The Achilles tendon and ground reaction force moment arms represented the shortest distance between the ankle joint axis and the line of action of each force. The Achilles tendon and joint reaction forces were calculated by solving motion of the foot equations for each instance during the contact phase of running. The ground reaction force was significantly greater for the forefoot and midfoot strikes than for the rearfoot strikes, whereas there was no difference between the midfoot and rearfoot strikes. The Achilles tendon and joint reaction forces were significantly greater for the forefoot strikes than for the other foot strikes, and these forces were greater for the midfoot strike than for the rearfoot strike. The ground reaction force moment arm was significantly greater for the forefoot strike than for the other foot strikes, and was greater for the midfoot strike than for the rearfoot strike. Meanwhile, there were no significant differences in the Achilles tendon moment arm among all foot strikes. The Achilles tendon and joint reaction forces were greatest for the forefoot strike, followed by the midfoot strike, and rearfoot strike. These differences were attributed mainly to differences in the ground reaction force moment arm among the three foot strike patterns.

The purpose of this study was to investigate the profile of adiponectin expression in slow soleus （SOL） and fast extensor digitorum longus （EDL） muscles of 10- and 100-week old mice, and to evaluate the effects of adiponectin analogue AdipoRon （AR） on myogenesis of C2C12 cells. Age-associated decrease in muscle weight in EDL was higher than that in SOL. Protein expression level of adiponectin in both SOL and EDL was increased by aging. Aging-associated up-regulation of adiponectin in SOL was lower than that in EDL. AR partially suppressed myogenic differentiation of C2C12 cells in a dose-dependent manner. However, AR-associated suppression of myogenesis was partially inhibited by knockdown of adiponectin receptor 1. Evidences suggests that aging-associated up-regulation of skeletal muscle-specific adiponectin may be a cause of sarcopenia, and strongly support “adiponectin paradox” in the regulation of skeletal muscle mass.

In this study, we investigated in university male long-distance runners whether the classification of gut microbiota changed according to an athlete&apos;s subjective condition. In addition, we used the Big-Five Factor Markers of personality traits to investigate whether changes in the intestinal microbial flora were related to emotional stability, with the aim of obtaining basic material useful for the field. The athletes were asked to take two stool samples for gut microflora analysis, one while in a “normal” condition （decided subjectively） and one when in a “worse” condition, excluding physical conditions such as when clearly affected by a common cold. Gut microbiota were classified by terminal restriction fragment length polymorphism analysis. The performance stability of each athlete was evaluated from changes in his competition performance and usual training record, assessed by the athlete&apos;s coach using a ten-point subjective evaluation. We examined the relationship between emotional stability and performance stability using the Big-Five Factor Markers inventory. There was a significant correlation between emotional stability and performance stability. Based on this result, the athletes were divided into high emotional stability and low emotional stability groups, and the amount of change in the gut microbiota classification between the “normal” condition and “worse” condition stool samples were examined. There was no significant difference between the two groups in the amount of change in the intestinal microbial community. However, the data suggested that the gut microbiota differs greatly between individuals. Further investigation of the relationship between detailed changes in gut microbiota and individuals&apos; mental and physical condition is warranted.

The aim of this study was to investigate the usefulness of the central arterial pressure waveform measured during dynamic exercise in the evaluation of peripheral vasodilatory dysfunction of individuals at the early stage of hypertension. We examined ninety-five volunteers （42±9 years） composed of normotensive and untreated hypertensive subjects who had resting blood pressure （BP） ranging from the normal to stage 1 hypertension. They exercised for 10 min on a bicycle ergometer at a heart rate （HR） equal to 50% of their HR reserve. At baseline, immediately （<1 min） and 5 min after the dynamic exercise, the peripheral pulse waveforms were recorded by a radial applanation tonometry. Central pressure waveforms were estimated using a generalized transfer function. Pulse pressure （PP） amplification, defined as the ratio of peripheral to central PP, was used as a marker of wave reflection. Endothelium-dependent peripheral vasodilatory response was assessed as flow-mediated dilation of the brachial artery. Compared to the resting state before exercise, the PP amplification significantly increased at the end of exercise, and thereafter it gradually decreased toward the baseline level. Before the exercise, the hypertensive subjects showed the lower PP amplification than normotensive subjects （1.32 vs. 1.46, P<.001）， and the differences between groups became more prominent at the end of exercise （1.66 vs. 1.85, P<.001）． When the subjects were divided into subgroups according to the tertiles of PP amplification after exercise, the subjects in the bottom tertile showed significantly reduced flow-mediated dilation （7.5±2.5%） than those in the intermediate and top tertiles （9.3±2.6% and 10.9±2.4%, P=.026）． Multivariate regression analysis revealed that the low PP amplification （β=0.435, P=.002） was independently associated with the decrease of flow-mediated dilation, independent of age, body mass index, brachial systolic BP, HDL-cholesterol, and HbA1c （R2=.381, P<.001）． These results suggest that the response of central arterial pressure waveform during dynamic exercise is associated with peripheral vasodilatory dysfunction and hence may be useful as a marker of subclinical vascular alterations in the early stages of hypertension.

The body composition and weight control are very important for athlete&apos;s conditioning and performance improvement. The ovarian hormones could effect on fluid retention. Therefore, it has been suggested the body weight and the body composition should be changed in the phase of menstrual cycle. The present study aimed to develop a weight control program according to the phases of the menstrual cycle based on a study of eight eumenorrheic women （age, 21.6 ± 0.4 years; height, 161.3 ± 1.8 cm） who volunteered to participate in this study. All participants cycled for 30 min at an intensity of 60% VO2peak. Blood samples were collected and respiratory gas was analyzed at rest （0 min） and at 30, 60, and 90 min after exercise during the follicular （FP）， ovulation （OV）， and luteal （LP） phases of one menstrual cycle. Blood levels of ovarian hormones （estradiol and progesterone）， catecholamines （adrenalin and noradrenalin）， glucose, free fatty acid （FFA）， renin activity, and aldosterone were assessed. Blood concentrations of estradiol were haigher greater during the OV and LP than during the FP at all time points. Body weight tended to increase during the LP compared with the OV （p = 0.06）．Renin activity significantly and positively correlated with progesterone （r = 0.632, p < 0.01）．The noradrenaline was significantly higher in the luteal phase than in the follicular phase. In conclusion, the increase in body weight during the LP was induced by an increase in body fluid volume. However, aerobic exercise performed during the luteal phase might reduce body fat.

Hyperthermia during exercise leads to increases in ventilation independently of metabolic factors, resulting in hypocapnia and cerebral hypoperfusion. This study examined the effects of sleep deprivation on body temperature and cardiorespiratory responses during exercise in the heat. Six male subjects performed a cycle exercise at 50% of peak oxygen uptake in the heat （37℃ ambient temperature and 50% relative humidity） until their esophageal temperature （Tes） reached 39℃ or they could no longer continue the exercise. Normal sleep （control trial） or ~28 h of wakefulness （sleep loss trial） preceded the exercise-heat test. Tes, minute ventilation （V･E），respiratory gases, sweat rate （ventilated capsule method） and skin blood flow （laser-Doppler），heart rate and arterial blood pressure during the exercise were measured continuously. Exercise duration did not differ between trials （P > 0.05）．Tes at rest tended to be lower in the sleep loss than control trial, and it during exercise and at the end of exercise did not differ between trials （P > 0.05）．Plotting ventilatory and thermoregulatory responses against Tes showed that V･E at Tes of 38.8℃ was higher in the sleep loss than control trial （P < 0.05），and the sensitivity of V･E to rising Tes （slope of the Tes- V･E relation） tended to be greater in the sleep loss than control trial. Sleep loss did not affect the Tes thresholds for sweating and cutaneous vasodilation and the sensitivities of the responses （P > 0.05）．These results indicate that during prolonged exercise in the heat, sleep deprivation can accelerate hyperthermia-induced hyperventilation during prolonged submaximal exercise in the heat.

Skeletal muscle is the major organ responsible for whole-body glucose metabolism and utilization. Heat stress （HS） has been implicated in the regulation of whole-body glucose homeostasis. Recently, we have demonstrated that short-term HS （for 10 and 30 min） in vitro activates insulin-independent glucose transport, at least in part by stimulating 5&apos;-AMP-activated protein kinase （AMPK） via decreased energy status in rat skeletal muscle. However, there have been no reports about the effect of acute HS （< 30 min） on glycogen and protein metabolism in skeletal muscle. The purpose of this study was to investigate the effect of short-term HS on glycogen and protein synthesis using rat skeletal muscle. Male Sprague-Dawley rats weighing 150 g were killed by cervical dislocation without anesthesia, and epitrochlearis muscles were isolated. Muscle was then incubated in the absence or presence of HS （42℃， 30 min） in alpha minimum essential medium containing 50 μU/mL insulin. HS decreased glycogen content and activated glycogen synthesis with decreasing the phosphorylation of glycogen synthase kinase 3β, without affecting the phosphorylation of glycogen synthase. HS tended to decrease protein synthesis, and correspondingly, HS decreased the phosphorylation of p70 ribosomal protein S6 kinase and 4E-binding protein 1. On the other hand, HS did not affect the mRNA expression of muscle-specific ubiquitin ligases: muscle atrophy F-box/atrogin-1 and muscle ring finger 1, or protein expression of autophagy-related markers: microtubule-associated protein 1 light chain 3 and p62. In conclusion, short-term HS might be a physiologically relevant stimulus that promotes glucose transport/glycogen synthesis axis and inhibit protein synthesis in skeletal muscle. Although further study is warranted, HS has similar action to exercise by acutely activating glycogen synthesis and suppressing protein synthesis with a reduction of the glycogen content in skeletal muscle.

The purpose of this study was to evaluate if cerebrovascular responsiveness to hypercapnia determined by a brief exposure to a high level of CO2 gas mixture is associated with arterial stiffness and aerobic capacity in young healthy adults. Twenty-four college students participated in this study. The study of cerebrovascular responsiveness to hypercapnia, arterial stiffness and aerobic capacity were conducted. To examine cerebrovascular responsiveness to hypercapnia, they wore a mask connected with 2-way valve and they were exposed without them knowing to a 10 % CO2 gas mixture just for 2 breaths to induce brief hypercapnia. To evaluate cerebrovascular response to hypercapnia, changes in total hemoglobin （tHb） on the forehead using near-infrared spectroscopy （NIRS） and end-tidal PCO2 （PETCO2） using a CO2 analyzer were measured continuously throughout the examination. The cerebrovascular responsiveness to hypercapnia was assessed as changes in tHb over changes in PETCO2. Arterial stiffness was assessed by the cardio-ankle vascular index （CAVI）. Peak O2 uptake was measured to evaluate aerobic capacity. Following the exposure to hypercapnic gas mean blood pressure and SaO2 were not affected, while heart rate was increased. By the exposure to hypercapnic gas PETCO2 was increased from 38±4mmHg to 51±3mmHg, and tHb over the forehead was increased by 0.012±0.012 mM. Among these subjects there was a negative correlation between CAVI and aerobic capacity （r=-0.47, P<0.05）. On the other hand, there was no correlation between cerebrovascular responsiveness to hypercapnia and aerobic capacity or CAVI. It was concluded that the cerebrovascular responsiveness to hypercapnia determined by a brief exposure to high level of CO2 and by NIRS is not associated with aerobic capacity or arterial stiffness in young healthy adults.t

Growing evidence has shown that certain biogenics produced during fermentation of milk could have physiological benefits. In a placebo-controlled double blind experimental design, we investigated the effect of a biogenic factor, milk casein hydrolysate, derived from lactobacillus fermented milk on muscle damage and glucose metabolism after exercise in middle-aged to elderly people. Ten middle-aged to elderly subjects （49 ± 2 yr） participated in each of two trials of the study: exercise with placebo （placebo trial） and exercise with milk casein hydrolysate （active trial）. Participants carried out downhill walking （decline grade: -5%, speed: 5 km/h, time: 30 min）. Test tablet （placebo or active） was taken before and after exercise in double-blind method. On the next day of exercise, muscle damage and metabolic parameters were measured. Although muscle soreness was not difference between trials, plasma creatine kinase was significantly lower in the active trial than the placebo trial. In addition, carbohydrate oxidation after glucose administration was significantly higher in the active trial than the placebo trial. These observations suggested that intake of milk casein hydrolysate before and after low intensity exercise could improve glucose metabolism associated with suppressing delayed-onset muscle damage.

Since patients with spinal cord injury lose their functions of the autonomic nervous system, it is difficult to regulate body temperature at perspiration and dilation / contraction of blood vessels. These problems are serious barriers for severely disabled people to participate in sports. And also, for physically disabled athletes, temperature control is an important issue from the viewpoint of maintenance of conditions towards the exercise performance and improvement of training efficiency. In order to solve these problems, we have attempted to develop a body temperature control system using core temperature. In this study, we developed the deep body thermometer which measure estimated core temperature noninvasively. Then we performed an experiment with the athlete of the wheelchair marathon to monitor the core temperature during rest and exercise, using developed deep body thermometer. As a result, it became clear that the core temperature was higher in the back than in the head and rose after exercise rather than during exercise. In addition, verification of the measurement accuracy and response time of the developed deep body thermometer showed that it had sufficient performance as a sensor used for body temperature control. Furthermore, we attempted cooling system for temperature control, ergometer load experiments were conducted for healthy subjects using the cooling system. Experimental results showed that the rise of deep body temperature on the back was able to be controlled with enough cooling capability.

The present study aimed to determine the relationship between ectopic fat content and muscle or subcutaneous fat thickness of the upper arm and thigh in eight wheelchair basketball players （mean age, 41.0 ± 10.3 years）．Echo intensity and muscle thickness of the biceps brachii （Bi） and rectus femoris （RF），and of subcutaneous fat at same sites were determined by ultrasonography. Echo intensity was taken as ectopic fat content. Echo intensity was calculated based on the mean of a gray scale. Echo intensity was significantly higher for RF than Bi （p < 0.05）．Echo intensity significantly and inversely correlated with the muscle thickness of Bi and RF （both p < 0.05），whereas echo intensity and subcutaneous fat thickness of both muscles did not significantly correlate. A significant inverse association between echo intensity and muscle thickness persisted in the RF （p < 0.05），but not in the Bi after controlling for age. These findings suggest that ectopic fat content correlates with muscle mass in the thigh muscles of male wheelchair basketball players.

[Background] There are many reports of effects of compression wear, mainly in the case of high intensity exercise, such as reduction of heart rate and muscle pain. There are a few reports on this effect in daily life. [Purpose] Verify daily life activity state, [Method] Ten healthy adult men aged 20-50years rested after walking with and without wearing compression wear for 2minutes. Heart beat, brain waves, and salivary amylase during that period were measured. [Result] By wearing the compression wear, there was a significant difference in the activity of the parasympathetic nerve and an （EEG） wave. There was no significant difference in salivary amylase. [Conclusion] Psychological relaxation and arousal effect were demonstrated by wearing compression wear when resting after exercise for a few minutes such as seen in daily life behavior.

Cognitive function seems to decline during intense exercise. Concurrently, intense exercise decreases cerebral blood flow and cerebral oxygenation. Given that brain neuronal activity needs adequate oxygen delivery, decrease in cerebral blood flow and cerebral oxygenation may be associated with decline in cognitive function during intense exercise. The purpose of this study was to determine whether decrease in cerebral blood flow and cerebral oxygenation is associated with decline in cognitive function during intense exercise. Fifteen subjects （Age: 23.3 ± 1.8 yr, Height: 1.70 ± 0.06 m, Weight: 64.4 ± 5.8 kg, BMI: 22.5 ± 1.9 m2/kg, peak oxygen uptake （peak V･O2）: 47.3 ± 6.4 ml/min/kg） performed cognitive tasks at rest and during exercise on the cycle ergometer. Exercise intensities corresponded to 50% （moderate） and 80% （intense） of peak V･O2, and exercise duration were 7 min, respectively. The cognitive tasks consisted of Spatial Delayed Response task and GO/NOGO task, which required working memory and executive function. Cognitive function was evaluated by accuracy rate and reaction time of the tasks. Middle cerebral artery mean velocity （MCA Vmean） and cerebral oxygenation were monitored continuously. Cerebral oxygenation was recorded by near infrared spectroscopy and was expressed as changes from baseline. Intense exercise significantly impaired accuracy of the cognitive task as compared with rest and moderate exercise （rest: P < 0.05, moderate P < 0.01）． In contrast, reaction time in the cognitive task was not changed during intense exercise （P = 0.31）． MCA Vmean significantly increased during moderate exercise compared with rest （P < 0.01）． However, it significantly decreased during intense exercise compared with moderate exercise （P < 0.01）． Cerebral oxygenation tended to decrease during intense exercise relative to rest （P = 0.058）． These findings suggested that decreased in cerebral blood flow and cerebral oxygenation during intense exercise may be, least in part, associated with impairment in cognitive function.

It is well known that exercise training induces mitochondrial biogenesis in skeletal muscle. More recent studies have demonstrated that exercise also alters mitochondrial quality through the processes of fission and fusion. In this study, we investigated the effect of electrical stimulation-induced resistance training, which induces muscle hypertrophy, on the expression of proteins related to mitochondrial dynamics in rat skeletal muscle. We found that 4 weeks of resistance training increased protein levels of mitofusin 2（Mfn2） and optic atrophy 1 （Opa1），whereas protein levels of fission protein 1 （Fis1） and dynamin related protein 1 （Drp） were not altered. These results indicate that resistance training induces mitochondrial fusion, which may lead to an expanded mitochondrial reticular network along with muscle hypertrophy. It has been generally assumed that resistance training has little effect on skeletal muscle mitochondria. However, our results suggest that resistance exercise training may increase mitochondrial function without changing mitochondrial content in skeletal muscle.

The purpose of this study was to examine the effect of mild normobaric hypoxia on the sprint-interval training （SIT）-induced histone deacetylases （HDACs） protein expression and histone modification （acetylation） in the rat gastrocnemius muscle. Male Wistar rats （8 weeks old） were assigned randomly into normoxic control （NC），normoxic training （NT），hypoxic control （HC） or hypoxic training （HT） groups （n = 6/group）．The training group rats were exposed to SIT on a treadmill （1 min sprint and 2-5 min rest, 6-10 sets/day） 5-6 days per week for 9 weeks. After the experiment, the gastrocnemius muscles were removed and the expression of HDACs and the global levels of histone acetylation were determined by Western blot analysis. A two-way ANOVA revealed significant effects of hypoxia on the CS activity; however, no main effect of hypoxia and training was observed in the PGC1-α, SOD1, HIF-1 and VEGF. Although, there was no change in HDAC4 expression, effect of hypoxia on HDAC5 and effect of training on nuclear SIRT1 were observed. There were no significant effect of training on the acetylation of histone H3 among groups. However, de-acetylation of lysine residue 9 and 27 was significantly lower in the Hypoxic groups compared with the NC group. These findings demonstrated that SIT could enhance the improvement of the citrate synthase activity （oxidative capacity） in the gastrocnemius muscle, and it is partly related to the decline of histone acetylation mediated by the alternation of class III histone deacetylase SIRT1 in normobaric hypoxia.

Walking is widely conducted among people as an exercise for health promotion. In this study, in order to investigate more effective way of exercise compared to normal walking, muscle activities of the lower limb were measured utilizing electromyography so as to study the quantitative and qualitative analyses about muscle activities during exercises. Measurements of muscle activities during SLR exercise and during the examinations of the knee extension and flexion maximum strength in sitting position by electromyography showed that quantitative and qualitative evaluation of the muscle activities were possible. It also revealed that the amount or quality of muscle activities varies depending on the muscle difference. In particular, quality of muscle activities change by aging or it alters （frequencies decline） during continuous muscle contraction. In addition, we indicated the difference of the way or amount of muscle activities about several muscles in the lower extremities, depending on the normal walking, fast walking with wider stride or fast walking with increased pitch. And the amount of muscle activities was found to be increased during fast walking, both ways, and slow jogging compared to those during normal walking, and the muscles on which statistically significant increases were observed to be different depending on the way of fast walking or slow jogging. From these not merely conducting normal walking, but adopting different way of fast walking or slow jogging will lead to the training of various type of muscles and attain more effective exercise.

The aim of this study was to investigate the effects of Nihon Kendo kata on the secretion of sex steroid hormone in older and young kendo athletes. The subjects perfumed the 10 sets of Uchitachi and Shitachi each in Nihon Kendo kata. Measurement of rated perceived exertion （RPE） and heart rate and collection of blood sample were undergone before, immediately, 15, 30 and 60 minutes after kata. Blood glucose, lactate, ACTH, DHEA and free testosterone levels were measured. The Kata significantly increased （p < 0.05） RPE, heart rate and glucose. Furthermore, the kata increased the metabolism of ACTH and DHEA. There was no change in the concentration of free testosterone after kata. Aging did not affect the hormonal response to the kata. These results suggest that Nihon kendo kata could stimulate ACTH-DHEA systems.

It has been reported that 9,070,000 individuals had hypertension and 400,000,000 individuals had prehypertension in Japan, 2011. In view of the huge population of prehypertension and its high possibility to develop hypertension without a proper treatment, effective measures to control the blood pressure （BP） of this population is indispensable. For this population, aerobic exercise, such as walking, is generally recommended. However, it has been reported that exercise token at different timing of a natural day have different endocrinal response, which may also influence the BP. Further, among the types of aerobic exercise, walking is considered as an appropriate one for its flexibility and efficacy in lowering BP. Therefore, in this study, we focus on the influence of the timing of walking to the BP control for the prehypertension subjects. We recruited 6 subjects to participate in a 1-month walking therapy trial, who were randomly assigned to the afternoon group （AG） and the comparative group （CG）．In AG, subjects would have the walking exercise when their deep body temperature came to its peak in terms of circadian rhythm. In CG, subjects could choose to have the walking exercise in the morning or evening according to their own schedule. One-way ANOVA were used to test if the walking is effective in BP control for each individual. For the AG and CG, the differences between the baseline BPs and the BPs during 1-month walking therapy were then compared by two sample unpaired Student t test. According to One-way ANOVA, both AG and CG have a decreased systolic BP in the morning and evening before sleep （p < 0.05）， but have little influence on daytime BPs, which may also be influenced by the social factors. According to the Student t test, it suggests that the walking therapy in the afternoon might have a better effect on lowering the systolic BP in the morning and evening （p < 0.05）， and also on lowering the diastolic BP in the evening （p < 0.05）． The results of the trials suggest the possibility of attaining a better effect in BP control by adjusting the timing of walking according to personal circadian rhythm.