eLearning improves allied health professionals' knowledge and confidence to manage medically unexplained chronic fatigue states: A randomized controlled trial.

OBJECTIVES: To evaluate the impact of eLearning by allied health professionals on improving the knowledge and confidence to manage people with medically unexplained chronic fatigue states (FS). METHODS: Using a parallel randomized controlled trial design, participants were randomized 1:1 to a 4-week eLearning or wait-list control group. Knowledge and self-reported confidence in clinical skills to implement a therapeutic intervention for patients with FS were assessed at baseline, post-intervention and follow-up. Secondary outcomes (adherence and satisfaction with online education, knowledge retention) were also assessed. Data was analyzed using intention-to-treat. RESULTS: There were 239 participants were randomized (eLearning n = 119, control n = 120), of whom 101 (85%) eLearning and 107 (89%) control participants completed baseline assessments and were included in the analysis. Knowledge (out of 100) improved significantly more in the eLearning group compared to the control group [mean difference (95% CI) 8.6 (5.9 to 11.4), p < 0.001]. Knowledge was reduced in the eLearning group at follow-up but was still significantly higher than baseline [6.0 (3.7 to 8.3), p < 0.001]. Median change (out of 5) in confidence in clinical skills to implement the FS intervention was also significantly greater in the eLearning group compared to the control group [knowledge: eLearning (1.2), control (0); clinical skills: eLearning (1), control (0.1); both p < 0.001)]. Average time spent on the eLearning program was 8.8 h. Most participants (80%) rated the lesson difficulty as at the "right level", and 91% would recommend it to others. CONCLUSIONS: eLearning increased knowledge and confidence to manage FS amongst allied health professionals and was well-accepted. REGISTRATION: ACTRN12616000296437 https://anzctr.org.au/Trial/Registration/TrialReview.aspx?id=370222&isReview=true.

The effectiveness of activity pacing interventions for people with chronic fatigue syndrome: a systematic review and meta-analysis.

PURPOSE: To investigate whether activity pacing interventions (alone or in conjunction with other evidence-based interventions) improve fatigue, physical function, psychological distress, depression, and anxiety in people with chronic fatigue syndrome (CFS). MATERIALS AND METHODS: Seven databases were searched until 13 August 2022 for randomised controlled trials that included activity pacing interventions for CFS and a validated measure of fatigue. Secondary outcomes were physical function, psychological distress, depression, and anxiety. Two reviewers independently screened studies by title, abstract and full text. Methodological quality was evaluated using the PEDro scale. Random-effects meta-analyses were performed in R. RESULTS: 6390 articles were screened, with 14 included. Good overall study quality was supported by PEDro scale ratings. Activity pacing interventions were effective (Hedges' g (95% CI)) at reducing fatigue (-0.52 (-0.73 to -0.32)), psychological distress (-0.37 (-0.51 to -0.24)) and depression (-0.29 (-0.49 to -0.09)) and improving physical function (mean difference 7.18 (3.17-11.18)) when compared to no treatment/usual care. The extent of improvement was greater for interventions that encouraged graded escalation of physical activities and cognitive activities. CONCLUSION: Activity pacing interventions are effective in reducing fatigue and psychological distress and improving physical function in CFS, particularly when people are encouraged to gradually increase activities. REGISTRATION: PROSPERO CRD42016036087. IMPLICATIONS FOR REHABILITATIONA key feature of chronic fatigue syndrome (CFS) is a prolonged post-exertional exacerbation of symptoms following physical activities or cognitive activities.Activity pacing is a common strategy often embedded in multi-component management programs for CFS.Activity pacing interventions are effective in reducing fatigue and psychological distress and improving physical function in CFS, particularly when patients are encouraged to gradually increase their activities.Healthcare professionals embedding activity pacing as part of treatment should work collaboratively with patients to ensure successful, individualised self-management strategies.

The effect of exercise intensity on exercise-induced hypoalgesia in cancer survivors: A randomized crossover trial.

Pain is experienced by people with cancer during treatment and in survivorship. Exercise can have an acute hypoalgesic effect (exercise-induced hypoalgesia; EIH) in healthy individuals and some chronic pain states. However, EIH, and the moderating effect of exercise intensity, has not been investigated in cancer survivors. This study examined the effect of low- and high-intensity aerobic exercise on EIH in cancer survivors after a single exercise session as well as a brief period of exercise training (2-weeks, three exercise sessions per week). Participants (N = 19) were randomized to low- (30%-40% Heart Rate Reserve (HRR) or high- (60%-70% HRR) intensity stationary cycling for 15-20 min. Pressure pain thresholds (PPT) were assessed over the rectus femoris and biceps brachii before and after a single exercise session and again after a short training period at the assigned intensity. Then, following a 6-week washout period, the intervention was repeated at the other intensity. After the first exercise session, high-intensity exercise resulted in greater EIH over the rectus femoris than low intensity (mean difference ± SE: -0.51 kg/cm2  ± 0.15, Cohen's d = 0.78, p = 0.004). After a 2-week training period, we found no difference in EIH between intensities (0.01 kg/cm2  ± 0.25, d = 0.00 p = 0.99), with comparable moderate effect sizes for both low- and high-intensity exercise, indicative of EIH. No EIH was observed over the biceps brachii of the arm at either low or high intensity. Low-intensity exercise training may be a feasible option to increase pain thresholds in cancer survivors.

The Associations Between Physical Activity, Sleep, and Mood with Pain in People with Parkinson's Disease: An Observational Cross-Sectional Study.

BACKGROUND: Pain is common in Parkinson's disease (PD). In general and chronic pain populations, physical inactivity, poor sleep, and anxiety are associated with worse pain. However, little is known about these potential predictors of pain in PD. OBJECTIVE: This cross-sectional observational study investigated associations between measures of physical activity, sleep, and mood with pain in people with PD. METHODS: Pain was measured using the King's PD Pain Scale and the Brief Pain Inventory (pain severity and interference) in 52 participants with PD. Independent variables were categorised by demographics (age, gender), disease severity (MDS-UPDRS) and duration, central sensitization (Central Sensitization Inventory), physical activity (Incidental and Planned Exercise Questionnaire), sleep (Pittsburgh Sleep Quality Index), and mood (Hospital Anxiety and Depression Scale). RESULTS: Univariate regression analyses showed that increased disease severity, longer disease duration, greater central sensitization, increased physical activity, poor sleep, anxiety, and depression were associated with worse pain in one or more pain measures (p < 0.05). Multivariate regression models accounted for 56% of the variance in the King's Pain Scale, 25% pain severity and 36% in pain interference. Poor sleep independently contributed to worse pain scores in all models (ß 0.3-0.4, p < 0.05). CONCLUSION: Increased physical activity, poor sleep, anxiety, and depression are associated with worse pain scores in people with PD. For optimal management of pain in people with PD, sleep and mood may need to be addressed. Further, the nature of the relationship between physical activity and pain in PD requires further investigation.

The Relationship Between Daily Physical Activity and Pain in Individuals with Knee Osteoarthritis.

OBJECTIVE: Investigate the association between physical activity and pain severity in individuals with knee osteoarthritis. DESIGN: Cross-sectional; systematic review with meta-analyses. METHODS: Thirty-one participants with knee osteoarthritis underwent assessment of symptoms via self-report questionnaires and quantitative sensory testing. Following testing, physical activity and symptoms were monitored for seven days using accelerometers and logbooks. Cross-correlation analyses were performed on fluctuations in symptoms and physical activity across the week to detect the relative timing of the strongest association between pain and activity. These data were complemented by meta-analyses of studies that examined correlations between pain from knee osteoarthritis and physical activity or fitness. RESULTS: Pain severity at baseline correlated with moderate to vigorous physical activity (r2 = 0.161-0.212, P < 0.05), whereby participants who were more physically active had less pain. Conversely, the peak of the cross-correlation analyses was most often positive and lagging, which indicated that pain was increased subsequent to periods of increased activity. These superficially discrepant findings were supported by the results of a meta-analysis of 13 studies and 9,363 participants, which identified significant heterogeneity for associations between physical activity and pain (I2 = 91%). Stronger inverse associations were found between fitness and pain. CONCLUSIONS: Associations between physical activity and pain in people with knee osteoarthritis are variable and dynamic. These results reflect the beneficial impact of an active lifestyle and accompanying higher fitness. Yet, the side effect of acute periods of physical activity to transiently exacerbate pain may influence the behavior of some people to avoid activity because of pain.

Exercise-induced hypoalgesia is present in people with Parkinson's disease: Two observational cross-sectional studies.

BACKGROUND: Exercise is prescribed for people with Parkinson's disease to address motor and non-motor impairments, including pain. Exercise-induced hypoalgesia (i.e., an immediate reduction in pain sensitivity following exercise) is reported in the general population; however, the immediate response of pain sensitivity to exercise in people with Parkinson's disease is unknown. The purpose of this study was to investigate if exercise-induced hypoalgesia is present following isometric and aerobic exercise in people with Parkinson's disease, and if so, if it varies with the dose of aerobic exercise. METHODS: Thirty people with idiopathic Parkinson's disease and pain-free age-matched controls completed two observational studies evaluating the response to: (a) right arm isometric exercise; and (b) treadmill walking at low and moderate intensities. Pressure pain thresholds were measured over biceps brachii and quadriceps muscles immediately before and after exercise, with increased thresholds after exercise indicating exercise-induced hypoalgesia. RESULTS: Pressure pain thresholds increased in the Parkinson's disease group at all tested sites following all exercise bouts (e.g., isometric exercise, right bicep 29%; aerobic exercise, quadriceps, moderate intensity 8.9%, low intensity 7.1% (p ≤ 0.008)), with no effect of aerobic exercise dose (p = 0.159). Similar results were found in the control group. CONCLUSIONS: Overall, people with Parkinson's disease experienced an exercise-induced hypoalgesia response similar to that of the control group, the extent of which did not vary between mild and moderate doses of aerobic exercise. Further research is warranted to investigate potential longer term benefits from exercise in the management of pain in this population. SIGNIFICANCE: Isometric and aerobic exercise reduces pain sensitivity in people with Parkinson's disease. As exercise is important for people with Parkinson's disease, these results provide assurance that people with Parkinson's disease and pain can exercise without an immediate increase in pain sensitivity. The reduction in pain sensitivity with both modes and with low and moderate intensities of aerobic exercise suggests that people with Parkinson's disease can safely choose the mode and intensity of exercise that best suits their needs.

Exercise-based rehabilitation for cancer survivors with chemotherapy-induced peripheral neuropathy.

PURPOSE: Chemotherapy-induced peripheral neuropathy (CIPN) affects up to 40% of cancer survivors and is associated with functional deficits and an increased falls incidence. There are presently no strongly recommended treatment strategies for CIPN. The aim of this study was to evaluate the impact of a multimodal exercise intervention on CIPN symptoms and related functional deficits, as well as neurophysiologic parameters. METHODS: All outcomes were assessed before and after an 8-week exercise intervention (3-weekly sessions) and preceding 8-week control period at baseline, pre-exercise and post-exercise. Outcome measures were objective and patient-reported CIPN, standing and dynamic balance, mobility, quality of life, and sensory and motor nerve excitability and conduction studies. RESULTS: Twenty-nine cancer survivors (8 male, 21 female; mean age 61.6 ± 11.8 years) with CIPN symptoms affecting function completed all assessments. Objective and patient-reported CIPN, dynamic balance, standing balance in eyes open conditions, mobility and quality of life were improved from pre- to post-exercise (4.0 < F < 10.2; p < .05), with no changes over the control period (p > .21). No changes were observed in sensory or motor neurophysiologic parameters (p > .23). CONCLUSIONS: This study provides encouraging evidence of the rehabilitative potential of multimodal exercise for persisting CIPN in a post-treatment cohort. Large randomised controlled trials are justified to confirm observed benefits and determine the mechanisms and clinical significance.

Aerobic Exercise Reduces Pressure More Than Heat Pain Sensitivity in Healthy Adults.

OBJECTIVES: The hypoalgesic effects of exercise are well described, but there are conflicting findings for different modalities of pain; in particular for mechanical vs thermal noxious stimuli, which are the most commonly used in studies of exercise-induced hypoalgesia. The aims of this study were 1) to investigate the effect of aerobic exercise on pressure and heat pain thresholds that were well equated with regard to their temporal and spatial profile and 2) to identify whether changes in the excitability of nociceptive pathways-measured using laser-evoked potentials-accompany exercise-induced hypoalgesia. SUBJECTS: Sixteen healthy adults recruited from the University of New South Wales. METHODS: Pressure and heat pain thresholds and pain ratings to laser stimulation and laser-evoked potentials were measured before and after aerobic cycling exercise and an equivalent period of light activity. RESULTS: Pressure pain thresholds increased substantially after exercise (rectus femoris: 29.6%, d = 0.82, P < 0.001; tibialis anterior: 26.9%, d = 0.61, P < 0.001), whereas heat pain thresholds did not (tibialis anterior: 4.2%, d = 0.30, P = 0.27; foot: 0.44%, d = 0.02, P = 1). Laser-evoked potentials and laser heat pain ratings also changed minimally after exercise (d = -0.59 to 0.3, P > 0.06). CONCLUSIONS: This is the first investigation to compare the effects of exercise on pressure and heat pain using the same stimulation site and pattern. The results show that aerobic exercise reduces mechanical pain sensitivity more than thermal pain sensitivity.

The development and electronic delivery of case-based learning using a fast healthcare interoperability resource system.

HL7 International's Fast Healthcare Interoperability Resources (FHIR) standard provides a common format for sharing health data (eg, FHIR resources) and a RESTful Application Programming Interface (eg, FHIR API) for accessing those resources via a FHIR server connected to an electronic health record system or any other system storing clinical data. Substitutable Medical Applications and Reusable Technologies (SMART) leverages FHIR to create an electronic health record (EHR) agnostic app platform. It utilizes the OAuth standard to provide for authorization and authentication. This paper describes the development and informal evaluation of Case Based Learning on FHIR (CBL on FHIR), a prototype EHR-connected FHIR/SMART platform to provide interactive digital cases for use in medical education. The project goals were to provide a more interactive form of CBL than is possible on paper to more realistically simulate clinical decision making and to expose medical students to modern informatics systems and tools for use in patient care.

Barriers and facilitators of exercise experienced by cancer survivors: a mixed methods systematic review.

PURPOSE: Exercise has been shown to improve the health and well-being of people who have survived cancer. Yet, less than 40% of cancer survivors in Australia meet the recommended 150 min of moderate-intensity physical activity per week. Our objective was to systematically review the literature regarding barriers, facilitators and preferences for exercise for survivors of cancer. METHOD: MEDLINE, EMBASE, CINAHL, PsycINFO and Scopus were searched for qualitative and quantitative articles addressing barriers, facilitators and preferences for exercise in cancer survivors. Quality assessment was performed by two independent reviewers using the Mixed Methods Appraisal Tool. Thomas and Harden's method of thematic synthesis was used to amalgamate qualitative data while descriptive statistics were used to collate quantitative data. RESULTS: Nineteen studies were included (9 qualitative and 10 quantitative). Persisting treatment-related side effects was the most commonly reported barrier to initiating or maintaining exercise, followed by lack of time and fatigue. The most common facilitators of exercise were gaining a feeling of control over their health as well as managing emotions and mental well-being, while the preferred method of exercise was walking. We also identified a lack of useful information provided to survivors regarding exercise. CONCLUSION: Treatment-related side effects, lack of time and fatigue were key barriers to exercise for survivors of varied cancer types. Insufficient patient education may contribute to the belief that exercise is not helpful when experiencing side effects of treatment, including fatigue. Identifying barriers and facilitators leads to improved support and education from health professionals which is required to provide safe and effective exercise recommendations for survivors.

Autonomic nervous system function, activity patterns, and sleep after physical or cognitive challenge in people with chronic fatigue syndrome.

OBJECTIVE: To explore changes in autonomic functioning, sleep, and physical activity during a post-exertional symptom exacerbation induced by physical or cognitive challenge in participants with chronic fatigue syndrome (CFS). METHODS: Thirty-five participants with CFS reported fatigue levels 24-h before, immediately before, immediately after, and 24-h after the completion of previously characterised physical (stationary cycling) or cognitive (simulated driving) challenges. Participants also provided ratings of their sleep quality and sleep duration for the night before, and after, the challenge. Continuous ambulatory electrocardiography (ECG) and physical activity was recorded from 24-h prior, until 24-h after, the challenge. Heart rate (HR) and HR variability (HRV, as high frequency power in normalized units) was derived from the ECG trace for periods of wake and sleep. RESULTS: Both physical and cognitive challenges induced an immediate exacerbation of the fatigue state (p<0.001), which remained elevated 24-h post-challenge. After completing the challenges, participants spent a greater proportion of wakeful hours lying down (p=0.024), but did not experience significant changes in sleep quality or sleep duration. Although the normal changes in HR and HRV during the transition from wakefulness to sleep were evident, the magnitude of the increase in HRV was significantly lower after completing the challenge (p=0.016). CONCLUSION: Preliminary evidence of reduced nocturnal parasympathetic activity, and increased periods of inactivity, were found during post-exertional fatigue in a well-defined group of participants with CFS. Larger studies employing challenge paradigms are warranted to further explore the underlying pathophysiological mechanisms of post-exertional fatigue in CFS.

Explicit Education About Exercise-Induced Hypoalgesia Influences Pain Responses to Acute Exercise in Healthy Adults: A Randomized Controlled Trial.

The mechanisms through which acute exercise reduces pain (ie, exercise-induced hypoalgesia [EIH]) are poorly understood. This study aimed to determine if education about EIH affected pain responses after acute exercise in healthy adults. Participants received 15 minutes of education either about EIH (intervention, n = 20) or more general education about exercise and pain (control, n = 20). After this, the participants' knowledge and beliefs about exercise and pain were assessed. Pressure pain thresholds were then measured before and after 20 minutes of cycle ergometer exercise. Compared with the control group, the intervention group believed more strongly that pain could be reduced by a single session of exercise (P = .005) and that the information they had just received had changed what they thought about the effect of exercise on pain (P = .045). After exercise, pressure pain threshold increased in both groups, but the median increase was greater in the intervention group compared with the control group (intervention = .78 kg/cm2, control = .24 kg/cm2, P = .002, effect size [r] of difference = .49). These results suggest that cognitive processes in the appraisal of pain can be manipulated to influence EIH in healthy adults. PERSPECTIVE: This study shows that preceding a bout of exercise with pain education can alter pain responses after exercise. This finding has potential clinical implications for exercise prescription for people with chronic pain whereby pain education before exercise could be used to improve pain responses to that exercise.

Effects of Four Weeks of Strength Training on the Corticomotoneuronal Pathway.

PURPOSE: Neural adaptations to strength training have long been recognized, but knowledge of mechanisms remains incomplete. Using novel techniques and a design which limited experimental bias, this study examined if 4 wk of strength training alters voluntary activation and corticospinal transmission. METHODS: Twenty-one subjects were randomized into strength training (n = 10; 7 females, 3 males; 23.5 ± 7.5 yr; mean ± SD) and control groups (n = 11; 2 females, 9 males; 23.0 ± 4.2 yr). Strength training involved 12 sessions of high-force isometric contractions of the elbow flexors. Before and after training, voluntary activation of the elbow flexors was assessed via transcranial magnetic stimulation. Also, for the first time, magnetic stimulation of corticospinal axons was used to examine spinal-level adaptations to training. The evoked responses, termed cervicomedullary motor-evoked potentials (CMEPs), were acquired in resting biceps brachii in three arm postures. Muscle adaptations were assessed via electrical stimulation of biceps. RESULTS: Compared with the control group, the strength training group exhibited greater increases in maximal strength (12.8% ± 6.8% vs 0.0% ± 2.7%; P < 0.001), biceps electromyographic activity (27.8% ± 25.9% vs -5.2% ± 16.8%; P = 0.002), and voluntary activation (4.7% ± 3.9% raw change vs -0.1% ± 5.2%; P = 0.034). Biceps CMEPs in all arm postures were unchanged after training. Biceps twitch characteristics were also unchanged. CONCLUSIONS: Four weeks of isometric strength training of the elbow flexors increased muscle strength and voluntary activation, without a change in the muscle. The improvement in activation suggests that voluntary output from the cortex was better able to recruit motoneurons and/or increase their firing rates. The lack of change in CMEPs indicates that neither corticospinal transmission nor motoneuron excitability was affected by training.

Randomized Evaluation of Cognitive-Behavioral Therapy and Graded Exercise Therapy for Post-Cancer Fatigue.

CONTEXT: Cancer-related fatigue is prevalent and disabling. When persistent and unexplained, it is termed post-cancer fatigue (PCF). Cognitive behavioral therapy (CBT) and graded exercise therapy (GET) may improve symptoms and functional outcomes. OBJECTIVES: To evaluate the outcomes of a randomized controlled trial, which assigned patients with post-cancer fatigue to education, or 12 weeks of integrated cognitive-behavioral therapy (CBT) and graded exercise therapy (GET). METHODS: Three months after treatment for breast or colon cancer, eligible patients had clinically significant fatigue, no comorbid medical or psychiatric conditions that explained the fatigue, and no evidence of recurrence. The CBT/GET arm included individually tailored consultations at approximately two weekly intervals. The education arm included a single visit with clinicians describing the principles of CBT/GET and a booklet. The primary outcome was clinically significant improvement in self-reported fatigue (Somatic and Psychological HEalth REport 0-12), designated a priori as greater than one SD of improvement in fatigue score. The secondary outcome was associated improvement in function (role limitation due to physical health problems-36-Item Short Form Health Survey 0-100) comparing baseline, end treatment (12 weeks), and follow-up (24 weeks). RESULTS: There were 46 patients enrolled, including 43 women (94%), with a mean age of 51 years. Fatigue severity improved in all subjects from a mean of 5.2 (±3.1) at baseline to 3.9 (±2.8) at 12 weeks, suggesting a natural history of improvement. Clinically significant improvement was observed in 7 of 22 subjects in the intervention group compared with 2 of 24 in the education group (P < 0.05, χ2). These subjects also had improvement in functional status compared with nonresponders (P < 0.01, t-test). CONCLUSION: Combined CBT/GET improves fatigue and functional outcomes for a subset of patients with post-cancer fatigue. Further studies to improve the response rate and the magnitude of the benefit are warranted.

Randomised controlled trial of online continuing education for health professionals to improve the management of chronic fatigue syndrome: a study protocol.

INTRODUCTION: Chronic fatigue syndrome (CFS) is a serious and debilitating illness that affects between 0.2%-2.6% of the world's population. Although there is level 1 evidence of the benefit of cognitive behaviour therapy (CBT) and graded exercise therapy (GET) for some people with CFS, uptake of these interventions is low or at best untimely. This can be partly attributed to poor clinician awareness and knowledge of CFS and related CBT and GET interventions. This trial aims to evaluate the effect of participation in an online education programme, compared with a wait-list control group, on allied health professionals' knowledge about evidence-based CFS interventions and their levels of confidence to engage in the dissemination of these interventions. METHODS AND ANALYSIS: A randomised controlled trial consisting of 180 consenting allied health professionals will be conducted. Participants will be randomised into an intervention group (n=90) that will receive access to the online education programme, or a wait-list control group (n=90). The primary outcomes will be: 1) knowledge and clinical reasoning skills regarding CFS and its management, measured at baseline, postintervention and follow-up, and 2) self-reported confidence in knowledge and clinical reasoning skills related to CFS. Secondary outcomes include retention of knowledge and satisfaction with the online education programme. The influence of the education programme on clinical practice behaviour, and self-reported success in the management of people with CFS, will also be assessed in a cohort study design with participants from the intervention and control groups combined. ETHICS AND DISSEMINATION: The study protocol has been approved by the Human Research Ethics Committee at The University of New South Wales (approval number HC16419). Results will be disseminated via peer-reviewed journal articles and presentations at scientific conferences and meetings. TRIAL REGISTRATION: ACTRN12616000296437.

Transfer effects of step training on stepping performance in untrained directions in older adults: A randomized controlled trial.

BACKGROUND: Although step training improves the ability of quick stepping, some home-based step training systems train limited stepping directions and may cause harm by reducing stepping performance in untrained directions. This study examines the possible transfer effects of step training on stepping performance in untrained directions in older people. METHODS: Fifty four older adults were randomized into: forward step training (FT); lateral plus forward step training (FLT); or no training (NT) groups. FT and FLT participants undertook a 15-min training session involving 200 step repetitions. Prior to and post training, choice stepping reaction time and stepping kinematics in untrained, diagonal and lateral directions were assessed. RESULTS: Significant interactions of group and time (pre/post-assessment) were evident for the first step after training indicating negative (delayed response time) and positive (faster peak stepping speed) transfer effects in the diagonal direction in the FT group. However, when the second to the fifth steps after training were included in the analysis, there were no significant interactions of group and time for measures in the diagonal stepping direction. CONCLUSIONS: Step training only in the forward direction improved stepping speed but may acutely slow response times in the untrained diagonal direction. However, this acute effect appears to dissipate after a few repeated step trials. Step training in both forward and lateral directions appears to induce no negative transfer effects in diagonal stepping. These findings suggest home-based step training systems present low risk of harm through negative transfer effects in untrained stepping directions. TRIAL REGISTRATION: ANZCTR 369066.

Occlusion of blood flow attenuates exercise-induced hypoalgesia in the occluded limb of healthy adults.

Animal studies have demonstrated an important role of peripheral mechanisms as contributors to exercise-induced hypoalgesia (EIH). Whether these same mechanisms contribute to EIH in humans is not known. In the current study, pain thresholds were assessed in healthy volunteers (n = 36) before and after 5 min of high-intensity leg cycling exercise and an equivalent period of quiet rest. Pressure pain thresholds (PPTs) were assessed over the rectus femoris muscle of one leg and first dorsal interosseous muscles (FDIs) of both arms. Blood flow to one arm was occluded by a cuff throughout the 5-min period of exercise (or rest) and postexercise (or rest) assessments. Ratings of pain intensity and pain unpleasantness during occlusion were also measured. Pain ratings during occlusion increased over time (range, 1.5 to 3.5/10, all d > 0.63, P < 0.001) similarly in the rest and exercise conditions (d < 0.35, P > 0.4). PPTs at all sites were unchanged following rest (range, -1.3% to +0.9%, all d < 0.05, P > 0.51). Consistent with EIH, exercise significantly increased PPT at the leg (+29%, d = 0.69, P < 0.001) and the nonoccluded (+23%, d = 0.56, P < 0.001) and occluded (+8%, d = 0.19, P = 0.003) unexercised arms. However, the increase in the occluded arm was significantly smaller (d = -1.03, P < 0.001). These findings show that blocking blood flow to a limb during exercise attenuates EIH, suggesting that peripheral factors contribute to EIH in healthy adults.NEW & NOTEWORTHY This is the first demonstration in humans that a factor carried by the circulation and acting at the periphery is important for exercise-induced hypoalgesia. Further understanding of this mechanism may provide new insight to pain relief with exercise as well as potential interactions between analgesic medications and exercise.

Exploring the Mechanisms of Exercise-Induced Hypoalgesia Using Somatosensory and Laser Evoked Potentials.

Exercise-induced hypoalgesia is well described, but the underlying mechanisms are unclear. The aim of this study was to examine the effect of exercise on somatosensory evoked potentials, laser evoked potentials, pressure pain thresholds and heat pain thresholds. These were recorded before and after 3-min of isometric elbow flexion exercise at 40% of the participant's maximal voluntary force, or an equivalent period of rest. Exercise-induced hypoalgesia was confirmed in two experiments (Experiment 1-SEPs; Experiment 2-LEPs) by increased pressure pain thresholds at biceps brachii (24.3 and 20.6% increase in Experiment 1 and 2, respectively; both d > 0.84 and p < 0.001) and first dorsal interosseous (18.8 and 21.5% increase in Experiment 1 and 2, respectively; both d > 0.57 and p < 0.001). In contrast, heat pain thresholds were not significantly different after exercise (forearm: 10.8% increase, d = 0.35, p = 0.10; hand: 3.6% increase, d = 0.06, p = 0.74). Contrasting effects of exercise on the amplitude of laser evoked potentials (14.6% decrease, d = -0.42, p = 0.004) and somatosensory evoked potentials (10.9% increase, d = -0.02, p = 1) were also observed, while an equivalent period of rest showed similar habituation (laser evoked potential: 7.3% decrease, d = -0.25, p = 0.14; somatosensory evoked potential: 20.7% decrease, d = -0.32, p = 0.006). The differential response of pressure pain thresholds and heat pain thresholds to exercise is consistent with relative insensitivity of thermal nociception to the acute hypoalgesic effects of exercise. Conflicting effects of exercise on somatosensory evoked potentials and laser evoked potentials were observed. This may reflect non-nociceptive contributions to the somatosensory evoked potential, but could also indicate that peripheral nociceptors contribute to exercise-induced hypoalgesia.

Gene Expression in Response to Exercise in Patients with Chronic Fatigue Syndrome: A Pilot Study.

Chronic fatigue syndrome (CFS) is a debilitating disorder of unknown pathogenesis, characterized by fatigue, which is exacerbated after minimal exercise. We examined the effect of a single bout of aerobic exercise on leucocyte mRNA expression of genes putatively linked to exaggerated afferent signaling as an under-pinning of the fatigue state. A carefully-characterized sample of patients with CFS (N = 10) and healthy matched control participants (N = 12) were included. Participant ratings of fatigue and other symptoms, as well as blood samples, were obtained at baseline, and five other time-points up to 72 h after 25 min of moderate-intensity cycling exercise. Leucocyte mRNA of 19 metabolite-sensing, adrenergic, immune, and neurotransmission genes was examined using quantitative polymerase chain reaction. Patients with CFS reported substantial fatigue, functional impairment, and poor sleep at baseline (all p < 0.02), and exercise immediately induced worsened patients' fatigue (effect size, ES = 1.17). There were no significant changes in gene expression after exercise and patients did not differ from control participants at any time point. Higher levels of expression of ficolin (FCN1) and a purinergic receptor (P2RX4) in patients with CFS were found when all time points were combined. Patients with CFS did not show significant exercise-induced changes in leucocyte mRNA of 19 metabolite-sensing, adrenergic, immune and neurotransmission genes despite a prominent exacerbation of fatigue.