The Relationship Between Pain and Interoception: A Systematic Review and Meta-Analysis.

Interoception refers to the ability to sense internal bodily sensations. Research suggests that dysfunctions in interoception may be implicated in the transition to chronic pain, however, little work has examined interoceptive ability in pain states. Therefore, this systematic review aimed to assess whether interoception is altered in individuals experiencing pain. Following a systematic search of 4 electronic databases from inception to February 2023, 28 studies were included. Outcomes of interoceptive accuracy, interoceptive sensibility, and interoceptive awareness were meta-analysed. The risk of bias was assessed, and the certainty of the evidence was evaluated. Meta-analyses indicated that those with chronic pain display reduced interoceptive accuracy and increased interoceptive sensibility. Subgroup analyses indicated that the change in interoceptive sensibility is dependent on the measure used, with those with chronic pain scoring higher on measures focusing on attention to bodily sensations, while also scoring lower on emotional reactivity. No difference in interoceptive awareness was observed between individuals with chronic pain and pain-free controls. Only one study was found that measured interoception in those experiencing acute pain, while another study recruited those experiencing recurrent pain. These findings suggest that while those with chronic pain self-report as more interoceptively aware, they are less accurate at detecting internal bodily signals. Further research investigating domains of interoception in those experiencing acute and recurrent pain is needed. Data should be interpreted with caution as the certainty of evidence was very low for all completed analyses. This review was registered on the PROSPERO International Prospective Register of Systematic Reviews (Registration ID = CRD42022318843). PERSPECTIVE: This review considered the relationship between interoception and pain and found that an individual's ability to accurately sense internal signals is decreased in those with chronic pain, despite them reporting being more aware of internal sensations. However, there remains little research examining interoception in non-chronic pain states.

The Effects of Transcranial Direct Current Stimulation and Exercise on Salivary S100B Protein Indicated Blood-Brain Barrier Permeability: A Pilot Study.

OBJECTIVE: This study aimed to assess the effect of transcranial direct current stimulation (tDCS) and exercise on blood-brain barrier (BBB) permeability in humans as assessed through the quantification of the salivary protein biomarker S100B. It was hypothesized that active tDCS would induce a significant increase in salivary S100B concentration when compared with sham stimulation and no stimulation. It also was hypothesized that the increase in salivary S100B concentration would be greater after active tDCS and exercise than after tDCS or exercise alone. MATERIALS AND METHODS: A total of 13 healthy adults (five male, eight female), ranging in age from 21 to 32 years, underwent three experimental conditions (active tDCS, sham tDCS, inactive control). To assess exercise- and tDCS-induced changes in BBB permeability, S100B in saliva was measured. Saliva samples were taken before tDCS, after tDCS, and immediately after a ramped cycling time-to-exhaustion (TTE) task. Active tDCS involved the application of anodal stimulation over the primary motor cortex for 20 minutes at 2 mA. RESULTS: S100B concentrations in the control condition did not differ significantly from the active condition (estimate = 0.10, SE = 0.36, t = 0.27, p = 0.79) or the sham condition (estimate = 0.33, SE = 0.36, t = 0.89, p = 0.38). Similarly, S100B concentrations at baseline did not differ significantly from post-intervention (estimate = -0.35, SE = 0.34, t = -1.03, p = 0.31) or post-TTE (estimate = 0.66, SE = 0.34, t = 1.93, p = 0.06). CONCLUSIONS: This research provides novel insight into the effect of tDCS and exercise on S100B-indicated BBB permeability in humans. Although the effects of tDCS were not significant, increases in salivary S100B after a fatiguing cycling task may indicate exercise-induced changes in BBB permeability.

Teamwork measure relates to provider experience, burnout, and intent to stay.

OBJECTIVES: To develop a brief teamwork measure and determine how teamwork relates to provider experience, burnout, and work intentions. STUDY DESIGN: Survey of clinicians. METHODS: We analyzed data from Optum's 2019 biannual clinician survey, including a validated burnout measure and measures of provider experience and intent to stay. A 6-item measure of team effectiveness (TEAM) focused on efficiency, communication, continuous improvement, and leadership. Construct validity was assessed with content, reliability, and correlation with burnout. Generalized estimating equations with robust SEs determined relationships among TEAM score, provider experience, and intent to stay, controlling for demographics, clustering, and practice factors. RESULTS: Of 1500 physicians and advanced practice clinicians (1387 with complete data; response rate 56%), there were 58% in primary care; 57% were women, and 38% identified as Asian, Black/Hispanic, or another race/ethnicity other than White non-Hispanic. Burnout was present in 30%. The Cronbach α was excellent (0.86), and TEAM correlated with the validated burnout measure (adjusted odds ratio [OR] of lower burnout with high TEAM score, 0.28; 95% CI, 0.19-0.40; P < .0001). Clinicians with TEAM scores of at least 4 were more likely to have positive provider experiences (79% favorable vs 24% with low TEAM score; P < .001), had lower burnout rates (17% vs 44%%; P < .001), and more often intended to stay (93% vs 65%; P < .001). TEAM index score was strongly associated with provider experience (adjusted OR, 11.72; 95% CI, 8.11-16.95; P < .001) and intent to stay (adjusted OR, 7.24; 95% CI, 5.34-9.83; P < .001). CONCLUSIONS: The TEAM index is related to provider experience, burnout, and intent to stay, and it may help organizations optimize clinical work environments.

The effects of high-definition transcranial direct current stimulation on pain modulation and stress-induced hyperalgesia.

Background: The dorsolateral prefrontal cortex (DLPFC) has been implicated in the modulation of pain-related signals. Given this involvement, manipulation of the DLPFC through transcranial direct current stimulation (tDCS) may influence internal pain modulation and decrease pain sensitivity. Acute stress is also thought to affect pain, with increased pain sensitivity observed following the presentation of an acute stressor. Methods: A total of 40 healthy adults (50% male), ranging in age from 19 to 28 years (M = 22.13, SD = 1.92), were randomly allocated to one of two stimulation conditions (active and sham). High-definition tDCS (HD-tDCS) was applied for 10 min at 2 mA, with the anode placed over the left DLPFC. Stress was induced after HD-tDCS administration using a modified version of the Trier Social Stress Test. Pain modulation and sensitivity were assessed through the conditioned pain modulation paradigm and pressure pain threshold measurements, respectively. Results: Compared to sham stimulation, active stimulation produced a significant increase in pain modulation capacity. No significant change in pain sensitivity and stress-induced hyperalgesia was observed following active tDCS. Conclusion: This research shows novel evidence that anodal HD-tDCS over the DLPFC significantly enhances pain modulation. However, HD-tDCS had no effect on pain sensitivity or stress-induced hyperalgesia. The observed effect on pain modulation after a single dose of HD-tDCS over the DLPFC is a novel finding that informs further research into the utility of HD-tDCS in the treatment of chronic pain by presenting the DLPFC as an alternative target site for tDCS-induced analgesia.

Large area stimulated emission luminescent solar concentrators modelled using detailed balance consistent rate equations.

Stimulated emission luminescent solar concentrators (SELSCs) have the potential to reduce escape cone losses in luminescent solar concentrators (LSCs). However, a functional SELSC is yet to be demonstrated. Previous numerical studies and detailed balance limits provide guidance, but they also contradict and likely overestimate performance and underestimate requirements. In this work, we introduce a rate-equation model with inversion requirements compatible with detailed balance limits and apply this model to the numerical modelling of window-sized SELSCs. We find that the optimal pump photon energy for both LSCs and SELSCs is 1.35 eV and the potential improvement of SELSCs over LSCs is found to be 19.3%. The efficiencies found are much lower than those specified in previous work due to the increase in Stokes shift required for a highly luminescent material. We also find that SELSCs are more attractive at higher matrix losses, that emission linewidths <0.05  eV are desirable, and that SELSC devices can potentially achieve performance equal to LSCs at low illumination levels and simultaneously exceed it by up to 16.5% at 1-sun illumination.

Australian University Nursing and Allied Health Students' and Staff Physical Activity Promotion Preparedness and Knowledge: A Pre-Post Study Using an Educational Intervention.

The promotion of physical activity (PA) by health professionals is a key strategy to increase PA levels in the population. In this study, we investigated PA promotion, preparedness, and knowledge among university nursing and allied health students and staff, as well as PA resource usage within curricula, before and after an educational intervention. Students and staff from 13 health disciplines at one Australian university were invited to complete an online survey, and a curriculum audits were conducted before and after PA teaching resources were promoted by academic PA champions (n = 14). A total of 299 students and 43 staff responded to the survey pre-intervention, and 363 and 32 responded to the post-intervention, respectively. PA promotion role perception (≥93%) and confidence to provide general PA advice (≥70%) were high throughout the study. Knowledge of PA guidelines was poor (3−10%). Students of physiotherapy, sport and exercise science, as well as more active students, were more likely to be aware of the PA guidelines (p < 0.05). Over 12 months, PA promotion preparedness and knowledge did not change significantly, nor was there a change in the amount of PA content delivered, despite a significant increase in the use of the teaching resources across a number of disciplines (p = 0.007). Future research should be carried out to investigate the implementation of the resources over time and to develop additional strategies for PA promotion and education scaffolded across curricula.

Cognitive Resilience to Psychological Stress in Military Personnel.

Military personnel often perform complex cognitive operations under unique conditions of intense stress. This requirement to perform diverse physical and mental tasks under stress, often with high stakes, has led to recognition of the term 'tactical athlete' for these performers. Impaired cognitive performance as a result of this stress may have serious implications for the success of military operations and the well-being of military service men and women, particularly in combat scenarios. Therefore, understanding the nature of the stress experienced by military personnel and the resilience of cognitive functioning to this stress is of great importance. This review synthesises the current state of the literature regarding cognitive resilience to psychological stress in tactical athletes. The experience of psychological stress in military personnel is considered through the lens of the Transactional Theory of stress, while offering contemporary updates and new insights. Models of the effects of stress on cognitive performance are then reviewed to highlight the complexity of this interaction before considering recent advancements in the preparation of military personnel for the enhancement of cognitive resilience. Several areas for future research are identified throughout the review, emphasising the need for the wider use of self-report measures and mixed methods approaches to better reflect the subjective experience of stress and its impact on the performance of cognitive operations.

Development and Initial Validation of an Acute Readiness Monitoring Scale in Military Personnel.

Personnel in many professions must remain "ready" to perform diverse activities. Managing individual and collective capability is a common concern for leadership and decision makers. Typical existing approaches for monitoring readiness involve keeping detailed records of training, health and equipment maintenance, or - less commonly - data from wearable devices that can be difficult to interpret as well as raising privacy concerns. A widely applicable, simple psychometric measure of perceived readiness would be invaluable in generating rapid evaluations of current capability directly from personnel. To develop this measure, we conducted exploratory factor analysis and confirmatory factor analysis with a sample of 770 Australian military personnel. The 32-item Acute Readiness Monitoring Scale (ARMS) demonstrated good model fit, and comprised nine factors: overall readiness; physical readiness; physical fatigue; cognitive readiness; cognitive fatigue; threat-challenge (i.e., emotional/coping) readiness; skills-and-training readiness; group-team readiness, and equipment readiness. Readiness factors were negatively correlated with recent stress, current negative affect and distress, and positively correlated with resilience, wellbeing, current positive affect and a supervisor's rating of solider readiness. The development of the ARMS facilitates a range of new research opportunities: enabling quick, simple and easily interpreted assessment of individual and group readiness.

The Impact of Cognitive, Physical, and Psychological Stressors on Subsequent Cognitive Performance.

OBJECTIVE: To quantify the impact of performing challenging cognitive, physical and psychological tasks on subsequent cognitive performance, and whether differences in performance are predicted by psychological variables. BACKGROUND: Successful performance in many occupations depends on resilient cognition: the degree to which cognitive functions can withstand, or are resilient to, the effects of stress. Several studies have examined the effect of individual stressors on cognition; however, the capacity to compare different types of stress across studies is limited. METHOD: Fifty-eight participants completed cognitive, physical, psychological and control interventions, immediately preceded, and followed, by a battery of cognitive tasks. Self-efficacy and cognitive appraisal were reported at baseline. Perceived stress was recorded post-intervention. Subjective workload was recorded for each cognitive battery and intervention. RESULTS: Cognitive performance was impaired by the cognitive, physical and psychological interventions, with the greatest effect following the cognitive intervention. The subjective workload reported for the post-intervention cognitive battery was higher following the cognitive and physical interventions. Neither self-efficacy, cognitive appraisal, perceived stress nor subjective workload of the intervention strongly predicted post-intervention performance. CONCLUSION: Given the differences among interventions and cognitive domains, it appears that challenges to resilient cognition are broad and varied, and the mechanism(s) by which impairment occurs is complex. APPLICATION: Considering the increase in subjective workload for the post-intervention cognitive battery, a combination of subjective and objective measures of cognitive performance monitoring should be considered.

The Acute Readiness Monitoring Scale: Assessing Predictive and Concurrent Validation.

To complement and enhance readiness-monitoring capability, the Acute Readiness Monitoring Scale (ARMS) was developed: a widely applicable, simple psychometric measure of perceived readiness. While this tool may have widespread utility in sport and military settings, it remains unknown if the ARMS demonstrates predictive and concurrent validity. Here, we investigated whether the ARMS is: (1) responsive to an acute manipulation of readiness using sleep deprivation, (2) relates to biological markers of readiness [cortisol/heart-rate variability (HRV)], and (3) predicts performance on a cognitive task. Thirty young adults (aged 23 ± 4 years; 18 females) participated. All participants engaged in a 24-h sleep deprivation protocol. Participants completed the ARMS, biological measures of readiness (salivary cortisol, HRV), and cognitive performance measures (psychomotor vigilance task) before, immediately after, 24-, and 48-h post-sleep deprivation. All six of the ARMS subscales changed in response to sleep deprivation: scores on each subscale worsened (indicating reductions in perceived readiness) immediately after sleep deprivation, returning to baseline 24/48 h post. Lower perceived readiness was associated with reduced awakening responses in cortisol and predicted worse cognitive performance (slower reaction time). No relationship was observed between the ARMS and HRV, nor between any biological markers of readiness (cortisol/HRV) and cognitive performance. These data suggest that the ARMS may hold practical utility in detecting, or screening for, the wide range of deleterious effects caused by sleep deprivation; may constitute a quick, cheap, and easily interpreted alternative to biological measures of readiness; and may be used to monitor or mitigate potential underperformance on tasks requiring attention and vigilance.

Detailed balance limits for inversion in solar-pumped lasers and allied systems.

Solar-pumped lasers and optical amplifiers continue to draw research interest with advances in nanomaterials science and technology. Establishing accurate detailed balance limits for inversion in these systems is essential. In this Letter, we re-examine the threshold limits for inversion in broadband-pumped lasers, with reference to those provided by Roxlo and Yablonvitch [Opt. Lett.8, 271 (1983)OPLEDP0146-959210.1364/OL.8.000271], where they determined the minimum Stokes shift and the minimum ratio of pump band to emission band absorption constants-based on independent consideration of the emission at pump and emission frequencies. In contrast, the derivation here simultaneously accounts for emission in both the pump and emission bands, which in turn leads to a single consolidated inequality that serves to establish the revised threshold requirements for inversion. Upon applying this new unified relationship to solar-pumped devices, a large increase in the minimum required Stokes shifts for 1-sun devices, particularly at larger pump energies and smaller ratios of αp0/αe0, is found. The maximum possible efficiencies of solar-pumped devices are calculated using this new relation.

Waveguide photoreactor enhances solar fuels photon utilization towards maximal optoelectronic - photocatalytic synergy.

A conventional light management approach on a photo-catalyst is to concentrate photo-intensity to enhance the catalytic rate. We present a counter-intuitive approach where light intensity is distributed below the electronic photo-saturation limit under the principle of light maximization. By operating below the saturation point of the photo-intensity induced hydroxide growth under reactant gaseous H2+CO2 atmosphere, a coating of defect engineered In2O3-x(OH)y nanorod Reverse Water Gas Shift solar-fuel catalyst on an optical waveguide outperforms a coated plane by a factor of 2.2. Further, light distribution along the length of the waveguide increases optical pathlengths of the weakly absorptive green and yellow wavelengths, which increases CO product rate by a factor of 8.1-8.7 in the visible. Synergistically pairing with thinly doped silicon on the waveguide enhances the CO production rate by 27% over the visible. In addition, the persistent photoconductivity behavior of the In2O3-x(OH)y system enables CO production at a comparable rate for 2 h after turning off photo-illumination, enhancing yield with 44-62% over thermal only yield. The practical utility of persistent photocatalysis was demonstrated through outdoor solar concentrator tests, which after a day-and-night cycle showed CO yield increase of 19% over a day-light only period.

Images depicting human pain increase exercise-induced pain and impair endurance cycling performance.

The current study investigated whether viewing images of others in pain influences exercise-induced pain (EIP) and cycling performance. Twenty-one recreational cyclists attended five laboratory visits. The first two visits involved measuring participants' maximal aerobic capacity and familiarized participants to the fixed power (FP) and 16.1 km cycling time trial (TT) tasks. The FP task required participants to cycle at 70% of their maximal aerobic power for 10-minutes. In the subsequent three visits, participants performed the FP and TT tasks after viewing pleasant, painful or neutral images. Participants rated the subset of painful images as more painful than the pleasant and neutral images; with no difference in the pain ratings of the pleasant and neutral images. In the FP task, EIP ratings were higher following painful compared to pleasant images, while no differences in EIP were observed between any other condition . In the TT, performance did not differ between the pleasant and neutral conditions. However, TT performance was reduced after viewing painful images compared to neutral or pleasant images. HR, B[La], perceived exertion and EIP did not differ between the three conditions. These results suggest that viewing painful images decreases TT performance and increases pain during fixed intensity cycling. Abbreviations: EIP: Exercise Induced Pain; FP: Fixed Power; TT: Time Trial; HR:Heart Rate; B[La]: Blood Lactate; RPE: Rating of Perceived Exertion; IAPS: International Affective Picture System; PO: Power Output.

Plasmonics of Diffused Silver Nanoparticles in Silver/Nitride Optical Thin Films.

Metal-dielectric multilayers are versatile optical devices that can be designed to combine the visible transmittance of dielectrics with the electronic properties of metals for plasmonic and meta-material applications. However, their performances are limited by an interfacial optical absorption often attributed entirely to the metal surface roughness. Here, we show that during deposition of AlN/Ag/AlN and SiNx/Ag/SiNx multilayers, significant diffusion of Ag into the top dielectric layer form Ag nanoparticles which excite localized surface plasmon resonances that are primarily responsible for the interfacial optical absorption. Based on experimental depth profiles, we model the multilayer's silver concentration profile as two complementary error functions: one for the diffused Ag nanoparticles and one for the interface roughness. We apply the Maxwell-Garnett and Bruggeman effective medium theories to determine that diffusion characteristics dominate the experimental absorption spectra. The newfound metal nanoparticle diffusion phenomenon effectively creates a hybrid structure characteristic of both metal-dielectric multilayer and metal-dielectric composite.

Shock Index as a Predictor of Morbidity and Mortality in Pediatric Trauma Patients.

OBJECTIVES: Compared with unadjusted shock index (SI) (heart rate/systolic blood pressure), age-adjusted SI improves identification of negative outcomes after injury in pediatric patients. We aimed to further evaluate the utility of age-adjusted SI to predict negative outcomes in pediatric trauma. METHODS: We performed an analysis of patients younger than 15 years using the National Trauma Data Bank. Elevated SI was defined as high normal heart rate divided by low-normal blood pressure for age. Our primary outcome measure was mortality. Secondary outcomes included need for a blood transfusion, ventilation, any operating room/interventional radiology procedures, and intensive care unit stay. Multiple logistic regressions were performed. RESULTS: Twenty-eight thousand seven hundred forty-one cases met the study criteria. The overall mortality rate was 0.7%, and 1.7% had an elevated SI. Patients with an elevated SI were more likely (P < 0.001) to require blood transfusion, ventilation, an operating room/interventional radiology procedure, or an intensive care unit stay. An elevated SI was the strongest predictor for mortality (odds ratio [OR] 22.0) in pediatric trauma patients compared with hypotension (OR, 12.6) and tachycardia (OR, 2.6). CONCLUSIONS: Elevated SI is an accurate and specific predictor of morbidity and mortality in pediatric trauma patients and is superior to tachycardia or hypotension alone for predicting mortality.

Patterned Optoelectronic Tweezers: A New Scheme for Selecting, Moving, and Storing Dielectric Particles and Cells.

Optical micromanipulation has become popular for a wide range of applications. In this work, a new type of optical micromanipulation platform, patterned optoelectronic tweezers (p-OET), is introduced. In p-OET devices, the photoconductive layer (that is continuous in a conventional OET device) is patterned, forming regions in which the electrode layer is locally exposed. It is demonstrated that micropatterns in the photoconductive layer are useful for repelling unwanted particles/cells, and also for keeping selected particles/cells in place after turning off the light source, minimizing light-induced heating. To clarify the physical mechanism behind these effects, systematic simulations are carried out, which indicate the existence of strong nonuniform electric fields at the boundary of micropatterns. The simulations are consistent with experimental observations, which are explored for a wide variety of geometries and conditions. It is proposed that the new technique may be useful for myriad applications in the rapidly growing area of optical micromanipulation.

Escape from an Optoelectronic Tweezer Trap: experimental results and simulations.

Optoelectronic tweezers (OET) are a microsystem actuation technology capable of moving microparticles at mm s-1 velocities with nN forces. In this work, we analyze the behavior of particles manipulated by negative dielectrophoresis (DEP) forces in an OET trap. A user-friendly computer interface was developed to generate a circular rotating light pattern to control the movement of the particles, allowing their force profiles to be conveniently measured. Three-dimensional simulations were carried out to clarify the experimental results, and the DEP forces acting on the particles were simulated by integrating the Maxwell stress tensor. The simulations matched the experimental results and enabled the determination of a new "hopping" mechanism for particle-escape from the trap. As indicated by the simulations, there exists a vertical DEP force at the edge of the light pattern that pushes up particles to a region with a smaller horizontal DEP force. We propose that this phenomenon will be important to consider for the design of OET micromanipulation experiments for a wide range of applications.

Outcome of Pediatric Forearm Fracture Reductions Performed by Pediatric Emergency Medicine Providers Compared With Reductions Performed by Orthopedic Surgeons: A Retrospective Cohort Study.

OBJECTIVE: The aim of this study was to describe the outcome differences between board-certified orthopedists and pediatric emergency medicine (PEM) physicians conducting forearm fracture reductions. METHODS: We performed an analysis of patients between 1 and 14 years of age who presented to the emergency department (ED) with a forearm fracture requiring reduction. Data collected included reducing provider (PEM or orthopedist) and prereduction, postreduction, and follow-up fracture angles and displacements of both radius and ulna. We collected costs of care, both in the ED and at follow-up, as well as length-of-stay data. χ Tests and Fisher exact test compared associations between categorical variables; 2-sample t tests compared the PEM and orthopedic groups. Regression models were used to control for injury severity confounders. RESULTS: Of the 222 fractures, orthopedists reduced 135, and PEM doctors reduced 87. Based on fracture angle and displacement, the orthopedic group tended to have slightly more complicated cases. After adjusting for age and time to follow-up, fractures reduced by orthopedists were less likely to require remanipulation (adjusted odds ratio, 0.30; P = 0.020). The PEM group had a significantly lower length of stay (59.4 minutes shorter; P < 0.001) and a small overall saving in charges ($273.90; P = 0.47). CONCLUSIONS: Orthopedists performed better in maintaining fracture reductions compared with PEM physicians but lengthened the ED stay for our patients. There was no significant difference in cost.

Influence of luminescent material properties on stimulated emission luminescent solar concentrators (SELSCs) using a 4-level system.

The effect of various design and material parameters on the efficiency of stimulated emission-based luminescent solar concentrators (SELSCs) is studied numerically using a 4-level luminescent material containing concentrator. It is shown that the most efficient SELSCs have emission wavelengths of 1.5-1.8 µm, with a strong dependence on the Stokes shift. Depending on the parameters of the system, spontaneous emission is shown to nevertheless account for a significant fraction of potential energy generation. Assuming a propagation loss constant of -0.1m-1, and a refractive index of 1.5, the optimal length of an SELSC is found to be ~1.5m. Given these losses and an efficiency target of 10% greater than traditional LSCs, the required material emission linewidth varies from 10 to 100nm, with maximum thicknesses of 3-30 µm. Further, when reflection and propagation losses are considered, a single laser pass is preferred over multiple passes. It is also shown that SELSCs are significantly less sensitive to luminescent quantum efficiency when compared to conventional LSCs due to the increased radiative emission rate.

Examining the relationship between endogenous pain modulation capacity and endurance exercise performance.

The aim of the current study was to examine the relationship between pain modulatory capacity and endurance exercise performance. Twenty-seven recreationally active males between 18 and 35 years of age participated in the study. Pain modulation was assessed by examining the inhibitory effect of a noxious conditioning stimulus (cuff occlusion) on the perceived intensity of a second noxious stimulus (pressure pain threshold). Participants completed two, maximal voluntary contractions followed by a submaximal endurance time task. Both performance tasks involved an isometric contraction of the non-dominant leg. The main analysis uncovered a correlation between pain modulatory capacity and performance on the endurance time task (r = -.425, p = .027), such that those with elevated pain modulation produced longer endurance times. These findings are the first to demonstrate the relationship between pain modulation responses and endurance exercise performance.