Optimized operation scheme of flash-memory-based neural network online training with ultra-high endurance

With the rapid development of machine learning,the demand for high-efficient computing becomes more and more urgent.To break the bottleneck of the traditional Von Neumann architecture,computing-in-memory(CIM)has attracted increasing attention in recent years.In this work,to provide a feasible CIM solution for the large-scale neural networks(NN)requiring continuous weight updating in online training,a flash-based computing-in-memory with high endurance(10^(9) cycles)and ultrafast programming speed is investigated.On the one hand,the proposed programming scheme of channel hot electron injection(CHEI)and hot hole injection(HHI)demonstrate high linearity,symmetric potentiation,and a depression process,which help to improve the training speed and accuracy.On the other hand,the low-damage programming scheme and memory window(MW)optimizations can suppress cell degradation effectively with improved computing accuracy.Even after 109 cycles,the leakage current(I_(off))of cells remains sub-10pA,ensuring the large-scale computing ability of memory.Further characterizations are done on read disturb to demonstrate its robust reliabilities.By processing CIFAR-10 tasks,it is evident that~90%accuracy can be achieved after 109 cycles in both ResNet50 and VGG16 NN.Our results suggest that flash-based CIM has great potential to overcome the limitations of traditional Von Neumann architectures and enable high-performance NN online training,which pave the way for further development of artificial intelligence(AI)accelerators.

Generation of endurance time excitation functions using spectral representation method

In this study,application of the spectral representation method for generation of endurance time excitation functions is introduced.Using this method,the intensifying acceleration time series is generated so that its acceleration response spectrum in any desired time duration is compatible with a time-scaled predefined acceleration response spectrum.For this purpose,simulated stationary acceleration time series is multiplied by the time dependent linear modulation function,then using a simple iterative scheme,it is forced to match a target acceleration response spectrum.It is shown that the generated samples have excellent conformity in low frequency,which is useful for nonlinear endurance time analysis.In the second part of this study,it is shown that this procedure can be extended to generate a set of spatially correlated endurance time excitation functions.This makes it possible to assess the performance of long structures under multi-support seismic excitation using endurance time analysis.

Effect of endurance training on the expression profile of circRNA-lncRNA-miRNA-mRNA in myocardial tissues of mice after exhaustive exercise

Objective:To clarify the effect of endurance training on the expression profile of circRNA-lncRNA-miRNA-mRNA in myocardial tissues of mice after exhaustive exercise.Methods:A total of 45 male C57BL/6 mice were randomly divided into control(C),low-strength endurance training(LSET)and high-strength endurance training(HSET)groups(n=15).The mice in the control group were not conducted to platform training.The mice in the LSET and HSET groups were conducted to platform training at 30%and 60%of exhaustive exercise once a day for 5 days a week,respectively.The exhaustion exercise was performed after 5 weeks of platform training.Total RNA was extracted from myocardial tissues,and the expression profile of circRNA-lncRNA-miRNA-mRNA in myocardial tissues was analyzed using Illimina transcriptome sequencing.Results:The distance and time of exhaustive exercise were longer in the LSET and HSET groups than in the control group,and the distance and time of exhaustive exercise were longer in the HSET group than in the LSET group(P<0.05).A total of 54 differentially expressed circRNAs(28 down-regulated and 26 up-regulated),7 differentially expressed lncRNAs(all down-regulated),3 differentially expressed miRNAs(1 down-regulated and 2 up-regulated)and 99 differentially expressed mRNAs(81 down-regulated and 18 up-regulated)were identified by transcriptome sequencing(P<0.05).Interaction network analysis revealed that ENSMUSG00000113041,MSTRG.79740,mmu-miR-374c-5p,18 down-regulated mRNAs and 3 up-regulated mRNAs formed a regulatory network.GO functional analysis revealed that the differentially expressed mRNAs were mainly enriched in primary metabolic processes and macromolecular synthesis and metabolic processes.KEGG pathway analysis revealed that the differentially expressed mRNAs were mainly enriched in complement and coagulation cascade pathways,estrogen signaling pathway and glucagon signaling pathway.Conclusion:Endurance training could alter the expression profile of circRNA-lncRNA-miRNA-mRNA in myocardial tissues of mice after exhaustive exercise,and these differentially expressed RNAs form a regulatory network that affects cardiomyocyte synthesis and metabolism and thus participates in the regulation of myocardial injury.

Endurance tests are the most reliable core stability related measurements

Purpose:To determine the intra-tester reliability of clinical measurements that assess five components related to core stability:strength. endurance,flexibility,motor control,and function. Methods:Participants were 15 college-aged males who had not suffered any orthopedic injury in the past year.Core strength measurements included eight isometric tests and a sit-up test.The four core endurance tests were the trunk flexor test,trunk extensor test,and bilateral side bridge tests.Flexibility tests included the sit-and-reach test and active range of the trunk and hip joint motions.Proprioception via passive reposition tests of the hips and a single limb balance test on an unsteady platform were used to evaluate core motor control.Functional measurements consisted of a squat test and a single leg hop test for time and distance.Measurements were performed during two data collection sessions with a week’s rest between the sessions.Intra-class correlation coefficients were calculated to establish reliability. Results:The overall intra-rater reliability for all core stability related measurements ranged from low(ICC = 0.35,left hip reposition) to very high(ICC = 0.98,sit-and-reach).As a group,the core endurance tests were observed to be the most reliable. Conclusion:There are highly reliable tests in each of the five groups.Overall,core endurance tests are the most reliable measurements,followed by the flexibility,strength,neuromuscular control,and functional tests,respectively.

Efficient structural seismic performance evaluation method using improved endurance time analysis

Evaluation of structural performance under seismic excitations from low intensity to high intensity is essential to verify the seismic resistant capacity of a structure, and usually carried out by the incremental dynamic analysis (IDA) method or pushover method. The recently developed endurance time (ET) method is another method that uses dynamic pushover excitations, i.e., endurance time acceleration function, to obtain results similar to those obtained by IDA or pushover methods with low computational cost and acceptable accuracy. This study proposes an improvement on the ET method by considering more restrictions for both the elastic and inelastic response spectra in the generation procedure, and by specifying a target duration. Four reinforced concrete frame structures with 4, 8, 12, and 16 stories are adopted to verify the accuracy of the improved method. Comparison of the results obtained by the proposed method, the ET method and the IDA method shows that the improved method has a higher accuracy than the ET method. For evaluation of structural responses under specifi c ground motion intensity, which is typically required in seismic design codes, the results obtained by the proposed method are compared with fi ve commonly used ground motion selection methods, and shows the proposed method provides acceptable accuracy for engineering applications.

Collapse assessment of steel moment frames using endurance time method

In endurance time(ET) method structures are subjected to a set of predesigned intensifying excitations. These excitations are produced in a way that their response spectrum, while complying with a specifi ed spectrum, intensifi es with time so they can be used approximately to simulate the average effects of several ground motions scaled to different intensities. In this paper applicability of the ET method for evaluating collapse potential of buildings is investigated. A set of four steel moment frames is used for collapse assessment. The process of using ET method in collapse evaluation is explained and the results are compared with incremental dynamic analysis(IDA) results. It is shown that although the computational effort using the ET method is much less than the IDA analysis, the results of both methods are consistent. Finally collapse fragility curves using ET and IDA methods are produced and it is shown that the probabilities of collapse in different hazard levels are also consistent.

How does high-intensity intermittent training affect recreational endurance runners? Acute and chronic adaptations: A systematic review

Objective: This systematic review aimed to critically analyze the literature to determine how high-intensity intermittent training(HIIT) affects recreational endurance runners in the short-and long-term.Methods: Electronic databases were searched for literature dating from January 2000 to October 2015. The search was conducted using the key words "high-intensity intermittent training" or "high-intensity interval exercise" or "interval running" or "sprint interval training" and "endurance runners" or "long distance runners". A systematic approach was used to evaluate the 783 articles identified for initial review. Studies were included if they investigated HIIT in recreational endurance runners. The methodological quality of the studies was evaluated using the Physiotherapy Evidence Database(PEDro) scale(for intervention studies) and the modified Downs and Black Quality Index(for cross-sectional studies).Results: Twenty-three studies met the inclusionary criteria for review. The results are presented in 2 parts: cross-sectional(n = 15) and intervention studies(n = 8). In the 15 cross-sectional studies selected, endurance runners performed at least 1 HIIT protocol, and the acute impact on physiological, neuromuscular, metabolic and/or biomechanical variables was assessed. Intervention studies lasted a minimum of 4 weeks, with 10 weeks being the longest intervention period, and included 2 to 4 HIIT sessions per week. Most of these studies combined HIIT sessions with continuous run(CR) sessions; 2 studies' subjects performed HIIT exclusively.Conclusion: HIIT-based running plans(2 to 3 HIIT sessions per week, combining HIIT and CR runs) show athletic performance improvements in endurance runners by improving maximal oxygen uptake and running economy along with muscular and metabolic adaptations. To maximize the adaptations to training, both HIIT and CR must be part of training programs for endurance runners.

Effect of Carbonitriding on Endurance Life of Ball Bearing Produced from SAE 52100 Bearing Steels

The present paper reports the unusual enhancement of endurance life of ball bearings subjected to carbonitriding treatment. The microstructure was characterized by scanning electron microscopy and correlated with hardness and X-ray diffraction analysis. Endurance tests at 90% reliability revealed that the carbonitrided bearings exhibit nearly ten times more life than the non-carbonitrided bearings. This is attributed to synergic combination of retained austenitic, fine martensitic microstructure and ultrafine carbide precipitates obtained by carbonitriding treatment.

Effects of Maca Extract on Exercise Endurance and Ultrastructure of Mitochondria in Spinal Neurons

[Objectives] To study the effects of maca extract on the exercise endurance and ultrastructure of mitochondria in spinal neurons.[Methods]First,50 Wistar rats were randomly divided into 5 groups. The control group: no swimming,administered intragastrically the same volume of distilled water; simple swimming group: free swimming,administered intragastrically the same volume of distilled water; maca extract groups: free swimming,and treated with 4. 0,5. 3,and 8. 0 g/kg dose of maca extracts. Swimming rats swam freely in the circulating water flow of swimming pool and administered for 15 d. On the 16 th d,after the swimming endurance test,the rats were killed painlessly. The ultrastructure of the mitochondria in the spinal neurons was observed with a projection electron microscope,muscle glycogen,malondialdehyde( MDA),superoxide dismutase( SOD),glutathione peroxidase( GSH-Px) and free calcium in muscle were measured by radioimmunoassay.[Results] Compared with the simple swimming group,the swimming time before sinking and total swimming time extended 19. 83%,60. 28%,77. 55% and 55. 34%,73. 91% and 94. 47% respectively,and the differences were statistically significant( P < 0. 01). The sinking times decreased by 34. 35%,51. 18% and 57. 96% respectively,the differences were statistically significant( P < 0. 01). MDA and free calcium decreased by 20. 10%,31. 49% and 38. 72%,respectively with statistically significant differences( P < 0. 01) and 6. 42%,17. 58%and 26. 35% respectively. The levels of SOD,GSH-Px and muscle glycogen increased by 5. 12%,22. 74%,52. 53%,44. 22%,77. 79%and 98. 45% respectively,with statistically significant differences( P < 0. 01) and 35. 08%,47. 83% and 81. 88%,respectively,with statistically significant differences( P < 0. 01). The volume density( Vd),surface density( Sd) and number density( Nd) of mitochondria of spinal neurons decreased by 7. 79%,18. 18%,31. 17%,16. 95%,27. 34%,43. 31% and 13. 51%,23. 19% and 43. 15% respectively.[Conclusions]Maca extract can protect ultrastructure of the mitochondria in the spinal neurons,antioxidant activity,increase muscle glycogen,and improving the exercise capacity.

Endurance催化剂在长庆石化重油催化裂化装置上的应用

由于生产调整,长庆石化公司140×104t/a重油催化裂化装置原料由常压渣油变为全减压渣油,原料密度增大、残炭含量增高,反应生焦量大,制约了装置的加工量。为此,试用了Endurance重油深度转化催化剂。该催化剂在对渣油原料深度转化的同时,可最大量地降低焦炭产率。试用结果表明:Endurance催化剂初活性较高,衰减慢,且持久活性表现良好,抗重金属污染能力强,催化剂性能稳定,一段转化率较好,回炼油量减少;重油裂解能力较强,可以显著提高轻柴油、液化气收率,但汽油产率略有下降;可降低汽油烯烃含量,同时会造成汽油辛烷值的降低(汽油烯烃含量下降约3个百分点,汽油辛烷值下降约1个单位),对轻柴油、液化气质量基本没有影响;可明显降低催化剂单耗,试用期间,催化剂平均单耗由原来的1.46kg/t原料下降至1.25kg/t原料。

Walking and Aerobic Capacity in Old Adults after Concentric and Eccentric Endurance Exercise at Self-Selected Intensities

Self-selected exercise intensity can be a useful exercise prescription tool for older adults;however, it is not known if it can elicit improvements in walking and aerobic capacity. In older adults, effects of concentric or eccentric endurance exercise at self-selected walking speed were examined on 1-mile indoor walk performance, predicted maximum oxygen uptake and physiological parameters. Twenty-four older adults (67 ± 4 years) completed 3 × 30 min treadmill walks per week for 12-weeks on level (LTW, n = 11, 0%) or downhill (DTW, n = 13, ﹣10%) treadmill gradient at a self- selected speed, which progressed every 4 weeks. Maximal oxygen uptake was predicted using a 1-mile walk at 4-week intervals with physiological responses recorded using a portable metabolic system. One-mile walking speed increased from baseline following 8- and 12-weeks (12 weeks: LTW: 13% ± 6%, DTW: 14% ± 9%,

Effects of mRNA, Protein Expression and Activity for Myocardial SOD2 by a Single Bout of or Long-Term Strenuous Endurance Exercise in Rats

Objective: To explore the effects of myocardial SOD2 by strenuous endurance exercise. Methods: 27 grown male SD rats were randomly divided into control group (C), a single bout of strenuous endurance exercise group (E1) and seventh-week strenuous endurance exercise group (E2). Real-time PCR was used to observe the changes of mRNA expression for myocardial SOD2. Western bolt was used to observe the changes of SOD2 protein expression. In addition, SOD2, T-SOD and SOD1 activity changes were observed. Results: Myocardial SOD2 expression level at mRNA and protein of Group E1, E2 was significantly higher than that in group C, and SOD2 and T-SOD activity in group E2 were significantly higher than those in group C. Those changes were more obvious in group E2. Conclusions: Strenuous endurance exercise can improve level of myocardial SOD2 expression at mRNA and protein, and enhance the activity for SOD2, thus increasing the activity for T-SOD. Effect of long-term strenuous endurance exercise was better than a single bout of one.

Effects of intermittent sprint and plyometric training on endurance running performance

Purpose:The purpose of this study was to compare the effects of intermittent sprint training and plyometric training on endurance running performance.Methods:Fourteen moderately trained male endurance runners were allocated into either the intermittent sprint training group(n = 7)or the plyometric training group(n = 7).The preliminary tests required subjects to perform a treadmill graded exercise test,a countermovement jump test for peak power measurement,and a 10-km time trial.Training included 12 sessions of either intermittent sprint or plyometric training carried out twice per week.On completion of the intervention,post-tests were conducted.Results:Both groups showed significant reduction in weekly training mileage from pre-intervention during the intervention period.There were significant improvements in the 10-km time trial performance and peak power.There was also significant improvement in relative peak power for both groups.The 10-km time trial performance and relative peak power showed a moderate inverse correlation.Conclusion:These findings showed that both intermittent sprint and plyometric training resulted in improved 10-km running performance despite reduction in training mileage.The improvement in running performance was accompanied by an improvement in peak power and showed an inverse relationship with relative peak power.

Multilayer doped-GeSe OTS selector for improved endurance and threshold voltage stability

Selector devices are indispensable components of large-scale memristor array systems.The thereinto,ovonic threshold switching(OTS)selector is one of the most suitable candidates for selector devices,owing to its high selectivity and scalability.However,OTS selectors suffer from poor endurance and stability which are persistent tricky problems for applica-tion.Here,we report on a multilayer OTS selector based on simple GeSe and doped-GeSe.The experimental results show im-proving selector performed extraordinary endurance up to 1010 and the fluctuation of threshold voltage is 2.5%.The reason for the improvement may lie in more interface states which strengthen the interaction among individual layers.These develop-ments pave the way towards tuning a new class of OTS materials engineering,ensuring improvement of electrical perform-ance.

Simple and scalable synthesis of super-repellent multilayer nanocomposite coating on Mg alloy with mechanochemical robustness,high-temperature endurance and electric protection

Multi-functionalization is the future development direction for protective coatings on metal surface,but has not yet been explored a lot.The effective integration of multiple functions into one material remains a huge challenge.Herein,a superhydrophobic multilayer coating integrated with multidimensional organic-inorganic components is designed on magnesium alloy via one-step plasma-induced thermal field assisted crosslinking deposition(PTCD)processing followed by after-thermal modification.Hard porous MgO ceramic layer and polytetrafluoroethylene(PTFE)nano-particles work as the bottom layer skeleton and filler components separately,forming an organic-inorganic multilayer structure,in which organic nano-particles can be crosslinked and cured to form a compact polymer-like outer layer with hierarchical surface textures.Remarkably,the chemical robustness after prolonged exposure to aqua regia,strong base and simulated seawater solution profits from polymer-like nanocomposite layer uniformly and compactly across the film bulk.Moreover,the self-similar multilayer structure coating endows it attractive functions of strong mechanical robustness(>100th cyclic rotary abrasion),stable and ultra-low friction coefficient(about 0.084),high-temperature endurance,and robust self-cleaning.The organic-inorganic multilayer coating also exhibits high insulating property with breakdown voltage of 1351.8±42.4 V,dielectric strength of 21.4±0.7 V/μm and resistivity of 3.2×10^(10)Ω·cm.The excellent multifunction benefits from ceramic bottom skeleton,the assembly and deposition of multidimensional nano-particles,and the synergistic effect of organic inorganic components.This study paves the way for designing next generation protective coating on magnesium alloy with great potential for multifunctional applications.

NEAR-INFRARED MONITORING OF THE LUMBAR ERECTOR SPINAE MUSCLE IN HEALTHY MEN AND WOMEN DURING STATIC AND DYNAMIC ENDURANCE WORK

Understanding muscle hemodynamics using near-infrared spectroscopy is increasingly evident in the recent spinal disorders-related literature.However,none of these human studies addressed the issue of physiological limits for the lumbar muscle within the same participants during various exercise modes.The purpose of this study is to evaluate physiological limits for the lumbar muscle during dynamic and static endurance tests.On three separate days,22 healthy men and women performed three endurance protocols(static prone trunk extension,arm cranking,and pushing
pulling)until volitional exhaustion.For each protocol,minimum and maximum oxygenation and blood volume responses from the right lumbar erector spinae were obtained using a continuous dual wavelength near-infrared spectroscopy(Micro-Runman,NIM Inc.,PA,USA).Statistical analysis showed that greatest reduction in oxygenation(minimum)were obtained during dynamic exercises:pushing
pulling(2.1 times)and arm cranking(2.03 times)versus static test (P<0:05).Physiological change(calculated as the difference between maximum during recovery and minimum at the point of volitional exhaustion)during static test was lower[(66-75%for oxygenation)and(34-46%for blood volume)]than dynamic exercises (P<0:05).Contrary to the theory that sufficient occlusion of bloodflow to the lumbar muscle is possible with static trunk extension,it was concluded that a dynamic protocol until volitional exhaustion might be a good alternative in establishing near-infrared spectroscopy-derived physiological limits to the lumbar muscle.Further research is essential to identify an optimal calibration procedure for establishing true hypoxic values for the human lumbar muscle.

Test of incremental respiratory endurance as home-based, standalone therapy in chronic obstructive pulmonary disease: A case report

BACKGROUND The prevalence of chronic obstructive pulmonary disease(COPD)is increasing worldwide,and at the same time it is associated with increased mortality and reduced quality of life.Efforts to build sustainable rehabilitation approaches to COPD treatment and prevention are crucial.The system of long-term pulmonary rehabilitation care is insufficient.The main reasons for the absence of these outpatient programs are the lack of experience,the lack of interest of insurance companies in secondary prevention programs,and the lack of healthcare facilities in large geographical areas.The possibility of at-home pulmonary rehabilitation models(telemonitoring and telecoaching)could solve this problem.CASE SUMMARY A 71-year-old man with severe COPD,Global Initiative for Obstructive Lung Diseases stage 3 underwent an 8-wk remotely monitored inspiratory muscle training with a device based on the test of incremental respiratory endurance method.Spirometry,body plethysmography,test of incremental respiratory endurance examination,6-min walking test,body mass index,airflow obstruction,dyspnea,exercise capacity index,and subjective perception of dyspnea were performed as part of the initial and final examination.The patient performed training at home,and the physiotherapist monitored the patient remotely through a web application that allowed the physiotherapist to evaluate all training parameters in real-time and respond to any problems.After 8 wk of home training,there was a significant increase in all monitored values:maximal inspiratory pressure,a novel parameter sustained maximal inspiratory pressure,forced expiratory volume in 1 s,total lung capacity,forced vital capacity,peak expiratory flow,and inspiratory capacity.There was also an improvement in the perception of dyspnea according to the COPD Assessment Test and a modified Medical Research Council Breathlessness Scale,an increase in exercise tolerance according to the 6-min walking test,and a decrease in the exercise capacity index as a predictor of prognosis.CONCLUSION Respiratory telerehabilitation was greatly beneficial in a cooperative patient with COPD and may represent an alternative therapeutic approach to the increasing incidence of all lung diseases.

Poor Wheel-Running Exercise Can Decrease Blood Pressure through Hormonal Control and Increase Endurance Exercise Capacity in Middle-Aged Normal Rats

The aim of this study was to examine the effects of voluntary wheel-running (WR) on body weight (BW), waist circumference, mesenteric fat mass (MFM), adipocyte size, circulating cytokines/hormones, blood pressure (BP) and exercise endurance capacity in 11-month-old normal rats. Three-week WR with about 0.2 km of daily running distance caused a gradual loss in BW despite an increased intake of food/water. MFM decreased as daily running distance increased. Moreover, there was a positive correlation between MFM and BW, waist circumference or adipocyte size. On the other hand, WR significantly decreased systolic/diastolic BPs, and increased endurance exercise capacity. WR rat sera contained lower concentrations of angiotensin II, aldosterone, vasopressin and endothelin-1 and higher concentration of brain natriuretic peptide compared with sedentary rat sera. Thus, WR-induced reduction in resting BPs may be accomplished by attenuated vasoconstriction, enhanced vasodilatation and reduction in blood volume. In addition, circulating vascular endothelial growth factor and interleukin-6 were higher in WR rats, suggesting angiogenesis, anti-inflammation and insulin-sensitization. These results support a prevalent idea that daily light-exercise is a potential strategy for preventing metabolic syndrome.

Effect of Low-Dose Sodium Bicarbonate Supplementation on Intermittent Endurance Performance

In this study, we investigated the effect of sodium bicarbonate (NaHCO3) supplementation at a dose of 0.2 g&middot;kg&minus;1 40 min before an exercise on intermittent endurance performance and gastrointestinal distress. The participants were six healthy male students of a university. The Yo-Yo intermittent recovery test level 2 (Yo-Yo IR2) was used for the evaluation of intermittent endurance. The participants ingested water (Cont) or NaHCO3 independently at three timings. After drinking water, the Yo-Yo IR1 was performed for 2 min as warm-up. After resting for 5 min, the Yo-Yo IR2 was initiated. The measurement items were exercise distance, nutrition intake, biochemical test results, and blood gas analysis findings. The participants who ingested NaHCO3 had a 14% extended distance than those who ingested Cont, and 2/3 of those who took NaHCO3 showed a better motor performance. No significant difference was observed between the participants who took Cont and NaHCO3 in terms of pH level at baseline, and the NaHCO3 level was significantly higher during pre- and post-exercise (p 3 in terms of bicarbonate ion level at baseline, and the NaHCO3 level was significantly higher during pre- and post-exercise (p 3 at a low dose (0.2 g&middot;kg&minus;1), their exercise ability during an intermittent endurance test has improved. Furthermore, when digestive absorption is considered, eating a meal in advance may be able to suppress the onset of gastrointestinal distress.

Muscle endurance measurement using a progressive workload and a constant workload by maximal voluntary contraction

Muscle endurance measurement using a progressive workload method may reduce pain sensation in the subject. This study aimed to examine the relationships between force-time parameters during sustained static gripping as measured by maximal voluntary contraction (MVC) using either a progressive workload (PW) or a constant workload (CW). Sixteen subjects performed sustained static gripping with 7 gradually increasing relative demand values of 20% to 80% MVC and sustained static gripping by MVC. The staging of progressive workload was 10 s for 20% MVC, 20 s each for 30, 40, 50, 60, and 70% MVC, and 10 s for 80% MVC. The forces exerted at 120 s in the CW and PW methods were at around the 23-27% MVC level. Peak force, final force, and force during the last 30 s for the PW method evaluated muscle endurance after 1 min and showed high correlations (r = 0.746 ? 0.895). Significant correlations (r = 0.575 ? 0.605) were found between time to 40% MVC in the CW method and peak force, final force, and force in the last 30 s in the PW method group. The peak force in the PW method may be useful for evaluating muscle endurance with a short testing time and without high pain sensation.