Perceived Exertion Research Articles

Aerobic and Anaerobic Fitness Levels of Pre-Professional Contemporary Dancers: An Exploration of 2 Dance-Specific Field Tests.

The primary aim of this study was to present descriptive heart rate (HR), heart rate recovery (HRR) and RPE data for the DAFT and HIDT within one sample of contemporary dance students. The second aim was to explore if objective (HR) and subjective (RPE) data were correlated between tests. 40 (11 males, 29 females) university dance students with a mean age of 18.8 ± 1.8 years performed the DAFT and HIDT on 2 separate occasions within 1 week. Measurements were HR after 4 minutes in all stages of the DAFT, the percentage of age-predicted maximal HR (%HRmax) of all stages of the DAFT and at the end of the HIDT, and peak HR (HRpeak) at the end of both tests. Subjective ratings of perceived exertion (RPE) and HR recovery after 1 minute of rest (HRR) were determined after the tests. HRpeak of the DAFT and HIDT were 188.1 ± 11.0 and 185.3 ± 7.3 beats·min-1, respectively. There were high positive correlations between HRpeak of the HIDT and stages 3 to 5 of the DAFT (r = 0.716-0.740, all P-values < .01). HRR (r = .678, P < .01) and %HRmax (r = .746, P < .01) showed moderate to high correlations between the DAFT and HIDT. The anaerobic training zone was reached in stages 4 and 5 of the DAFT and at the end of the HIDT. The subjective RPE scores did not significantly correlate between DAFT and HIDT, neither with objective HR data. Although the DAFT and HIDT differ in intensity and work-to-rest ratio, there were high correlations between HR and HRR data of both tests and both tests reached intensities above the anaerobic threshold (%HRmax > 85%).

Lateral Shuffle-Induced Fatigue Effects on Ankle Proprioception and Countermovement Jump Performance

To determine how lateral shuffling/lateral shuffle (LS) -induced fatigue affects ankle proprioception and countermovement jump (CMJ) performance. Eighteen male college athletes performed 6 modes of a repeated LS protocol with 2 distances (2.5 and 5 m) and 3 speeds (1.6, 1.8, and 2.0 m/s). After LS, ankle inversion proprioception (AIP) was measured using the active movement extent discrimination apparatus (AMEDA). CMJ, blood lactate (BLa), heart rate (HR) and rating of perceived exertion (RPE) were measured before and after LS. The number of changes of direction (CODs) in each protocol was recorded. LS-induced fatigue was evident in BLa, HR and RPE (all p &lt; 0.05), increasing with shorter shuffle distance and faster speed. RM-ANOVA showed a significant distance main effect on both AIP (p &lt; 0.01) and CMJ (p &lt; 0.05), but the speed main effect was only significant for CMJ (p ≤ 0.001), not AIP (p = 0.87). CMJ performance was correlated with BLa, HR and RPE (r values range from –0.62 to -0.32, all p ≤ 0.001). AIP was only correlated with CODs (r = -0.251, p &lt; 0.01). These results suggested that in LS, shorter distance, regardless of speed, was associated with worse AIP, whereas subsequent CMJ performance was affected by both LS distance and speed. Hence, AIP performance was not related to physiological fatigue, but CMJ performance was. Results imply that LS affects processing proprioceptive input and producing muscular output differently, and that these two aspects of neuromuscular control are affected by physiological fatigue to varying degrees. These findings have implications for injury prevention and performance enhancement.

Neuromechanical Differences between Pronated and Supinated Forearm Positions during Upper-Body Wingate Tests

Arm-cycling is a versatile exercise modality with applications in both athletic enhancement and rehabilitation, yet the influence of forearm orientation remains understudied. Thus, this study aimed to investigate the impact of forearm position on upper-body arm-cycling Wingate tests. Fourteen adult males (27.3 ± 5.8 years) underwent bilateral assessments of handgrip strength in standing and seated positions, followed by pronated and supinated forward arm-cycling Wingate tests. Electromyography (EMG) was recorded from five upper-extremity muscles, including anterior deltoid, triceps brachii lateral head, biceps brachii, latissimus dorsi, and brachioradialis. Simultaneously, bilateral normal and propulsion forces were measured at the pedal-crank interface. Rate of perceived exertion (RPE), power output, and fatigue index were recorded post-test. The results showed that a pronated forearm position provided significantly (p &lt; 0.05) higher normal and propulsion forces and triceps brachii muscle activation patterns during arm-cycling. No significant difference in RPE was observed between forearm positions (p = 0.17). A positive correlation was found between seated handgrip strength and peak power output during the Wingate test while pronated (dominant: p = 0.01, r = 0.55; non-dominant: p = 0.03, r = 0.49) and supinated (dominant: p = 0.03, r = 0.51; don-dominant: p = 0.04, r = 0.47). Fatigue changed the force and EMG profile during the Wingate test. In conclusion, this study enhances our understanding of forearm position's impact on upper-body Wingate tests. These findings have implications for optimizing training and performance strategies in individuals using arm-cycling for athletic enhancement and rehabilitation.

The six minute walk test in healthy young women

ObjectivesThe Six Minute Walk Test (6MWT) assesses functional capacity. We determined the reference range distance walked, heart rate change, and breathlessness in healthy women. DesignProspective observational study. Methods100 nulliparous women aged 18–40 performed two 6MWTs, with the second performed after heart rate returned to baseline. Borg scales compared expected and true breathlessness. ResultsReference range was 472–758 ​m, with distance mean (SD) of 615 (73.0) metres. Heart rate increase during exercise was 11 (11.8) beats per minute, recovering to baseline in 4.5 (3.9) minutes. 63 ​% of women overestimated breathlessness. ConclusionsThese data represent reference values for functional evaluation of healthy young women.

The Effects of Slow Breathing during Inter-Set Recovery on Power Performance in the Barbell Back Squat

Slow breathing (SB) reduces sympathetic nervous system activity, the heart rate (HR), and blood pressure (BP) and increases parasympathetic nervous system activity, HR variability, and oxygen saturation which may lead to quicker recovery between bouts of exercise. Therefore, the purpose of this study was to examine whether a SB technique using the 4-7-8 method between sets of barbell back squats (SQs) would attenuate drops in power and bar velocity. In a randomized, crossover design, 18 healthy resistance-trained college-aged males (age: 20.7 ± 1.4 years, body height: 178.6 ± 6.4 cm, body mass: 82.2 ± 15.0 kg, 4.5 ± 2.4 years of experience) performed 5 sets of 3 repetitions of SQs with normal breathing (CON) or SB during the 3-min recovery between sets. Peak and average power and bar velocity were assessed using a linear positioning transducer. HR recovery (RHR), systolic BP recovery (RBP), the rating of perceived exertion (RPE) and the rating of perceived recovery score (RS) were assessed after each set. There were no significant differences between conditions for peak and average power and bar velocity, RBP, RPE, and RS (p &gt; 0.211). SB led to a greater RHR after set 2 (SB: 51.0 ± 14.9 bpm vs. CON: 44.5 ± 11.5 bpm, p = 0.025) and 3 (SB: 48.3 ± 13.5 bpm vs. CON: 37.7 ± 11.7 bpm, p = 0.006) compared to the CON condition. SB was well tolerated, did not hinder nor improve training performance and improved RHR after the middle sets of SQs. Further investigations are warranted to examine the effects of other SB techniques and to determine SB’s effects on different training stimuli as well as its effects over an entire workout and post-workout recovery metrics.

Intermittent sequential pneumatic compression reduces post-exercise hemodilution and enhances perceptual recovery without improving subsequent cycling performance

Abstract Purpose The present study aims to evaluate the effects of intermittent sequential pneumatic compression (ISPC) in the short-term recovery of a repeated sprint interval exercise, including the assessment of power output performance, hematocrit, legs water, and perceptual recovery. Methods A randomized, counterbalanced, crossover design was conducted. Sixteen healthy trained individuals (F=7, M=9; 27.7 ± 9.4 years; BMI 22.3 ± 2.9) performed two trials of a cycling fatiguing exercise, followed by a recovery phase (ISPC or Sham), and a subsequent performance assessment exercise to evaluate the effects of ISPC in post-exercise recovery. Results There were no significant differences in cycling performance comparing both recovery modes. However, the decrease in the hematocrit levels after the recovery phase was less exacerbated in the ISPC condition compared to Sham (44.03 ± 1.33 vs. 42.38 ± 1.33 %; p = 0.047; d = 0.310). Likewise, the total quality recovery (TQR) was higher after the recovery in the ISPC condition (15.94 ± 0.16 vs. 14.75 ± 0.12 points; p = 0.045; d = 2.125), although no differences were shown previously in power output performance (371.8 ± 22.2 [46.5] vs. 372.4 ± 21.8 [47.2] W; p = 0.986) and rating of perceived exertion (RPE) (17.69 ± 0.41 vs. 17.56 ± 0.31; p = 0.700). Conclusions Contrary to our hypothesis, the application of intermittent sequential pneumatic compression after high-intensity exercise reduces the post-exercise hemodilution response and increases perceptual recovery. However, power output was similar between conditions, challenging the effectiveness of this recovery method in a short-term intervention.

Effect of a Long-Term Online Home-Based Supervised Exercise Program on Physical Fitness and Adherence in Breast Cancer Patients: A Randomized Clinical Trial

The purpose of the present study was to analyze the effect of a synchronous-supervised online home-based exercise program (HBG) during 24 weeks on body composition, physical fitness and adherence compared to an exercise recommendation group (ERG) without supervision with patients undergoing breast cancer treatment. Fifty-nine female breast cancer patients (31 in HBG and 28 in the ERG) undergoing cancer treatments participated in the present randomized clinical trial. The exercise program consisted of a 60 min combined resistance and aerobic supervised exercise session (6–8 points on Borg Scale CR-10, moderate intensity), twice a week during 24 weeks. The exercise recommendation group only received general recommendations to comply with the current ACSM guidelines. Body composition and physical fitness were assessed at baseline, 12 weeks and 24 weeks of the program. Adherence to the intervention was measured according to the minutes of exercise completed per session during each week. A general linear model of two-way repeated measures showed significant improvements (p &lt; 0.05) in physical fitness that were observed in the home-based exercise group at the baseline, 12-week and 24-week assessments compared to the exercise recommendation group. Adherence was also higher in the home-based exercise group. However, no changes (p &gt; 0.05) in body composition between groups and moments were observed. In this sense, supervised home-based exercise interventions can be an interesting strategy to improve physical fitness and adherence rates in breast cancer patients undergoing treatment.

Six-minute walk test in healthy British service personnel

IntroductionThe 6 min walk test (6MWT) is a widely used, safe and effective submaximal exercise test. The primary outcome is the distance walked, but additional physiological and patient-reported metrics can...

Effects of Heat Exposure and Ice Slurry Ingestion on Risk-Taking Behavior in Healthcare Workers.

Healthcare workers (HCWs) wearing personal protective equipment (PPE) experience physiological strain that can impair motor and psychological functions, potentially affecting patient care. We assessed the effects of heat exposure on maximal strength and risk-taking behavior amongst PPE-wearing HCWs and the efficacy of ice slurry to alleviate adverse effects. 17 HCWs completed two experimental trials in a crossover design, consuming 5 g × kg-1 of body mass of ambient drink (AMB) or ice slurry (ICE) before donning PPE and undergoing 2-h of simulated decontamination exercise (wet-bulb globe temperature (WBGT): 25.9 ± 0.8 °C, PPE microenvironment WBGT: 29.1 ± 2.1 °C). Body core temperature (Tc), heart rate (HR), chest skin temperature (Tsk), ratings of perceived exertion (RPE), thermal sensation (RTS), maximal voluntary contraction (MVC), risk-taking behavior (Balloon Analogue Risk-Taking task; BART) and salivary cortisol were assessed. Pre- to post-drinking ∆Tc was greater in ICE (-0.2 ± 0.1 °C) than AMB (-0.0 ± 0.1 °C, P = 0.003). Post-drinking RTS was lower in ICE (2.7 ± 1.2) than AMB (4.1 ± 0.4, P < 0.001). ICE and AMB had similar Tc and HR (both P > 0.05), but Tsk was lower in ICE than AMB (P = 0.049). A lower MVC (30.3 ± 6.7 kg vs 27.4 ± 4.9 kg, P = 0.001) and higher BART adjusted total pump count (472 ± 170 pumps vs 615 ± 174 pumps, P = 0.017) was observed pre- to post-trial in AMB but absent in ICE (both P > 0.05). Salivary cortisol was similar between trials (P = 0.42). Heat-exposed PPE-wearing HCWs had impaired maximal strength and elevated risk-taking behavior. This may increase the risk of avoidable workplace accidents that can jeopardize HCWs and patient care. Ice slurry ingestion alleviated these heat-related impairments, suggesting its potential as an ergogenic aid.

The association between six-minute walk test and one minute sit to stand test in patients with acute exacerbations of COPD

ABSTRACT Aim: Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are a major complication of COPD and a leading cause of hospitalization, detrimentally affecting functional exercise capacity. The 6-minute walk test (6MWT) is a reliable measure of exercise capacity in chronic lung diseases. Conversely, the 1-minute sit-to-stand test (1STST) offers a simpler assessment of physical function. The aim was to demonstrate the association of functional exercise capacity assessed by 1STST and 6MWT in COPD patients with acute exacerbation. Materials and Methods: In this study, 37 hospitalized patients with acute exacerbation COPD (mean age:66 years) underwent assessments including pulmonary function testing, 6MWT, 1STST and modified Medical Research Council (MMRC). Parameters such as heart rate, oxygen saturation, and perceived dyspnea (via the modified Borg scale) were monitored during tests. Results: The results showed a significant correlation between 6MWT and 1STST performance (r=0.656, p&amp;lt;0.001). Notably, end-tidal oxygen saturation differed between tests, with the 6MWT showing higher end-tidal dyspnea scores. During recovery, 1STST induced increased heart rate and decreased oxygen saturation. Both 6MWT and 1STST were negatively associated with age and MMRC. Positive correlations were observed between 6MWT and FEV1(L) and PEF(L). Conclusions: Similar to the 6MWT, the 1STS test may be used to evaluate how well patients with AECOPD perform during functional exercise. We propose that the 1STST is a suitable alternative to the 6MWT for the assessment of functional exercise performance during hospitalization in AECOPD patients.

Neural Respiratory Drive During Different Dyspnea Relief Positions and Breathing Exercises in Individuals With COPD.

When the work load of the respiratory muscles increases and/or their capacity decreases in individuals with COPD, respiratory muscle activation increases to maintain gas exchange and respiratory mechanics, and perception of dyspnea occurs. The present study aimed to compare diaphragm and accessory respiratory muscle activation during normal breathing, pursed-lip breathing, and breathing control in different dyspnea relief positions, supine and side lying. A cross-sectional study design was used. Sixteen individuals with COPD age between 40-75 y were included. Pulmonary function was evaluated by spirometry, muscle activation by surface electromyography, and dyspnea by the modified Borg scale. Muscle activation was measured in the diaphragm, scalene, sternocleidomastoid, and parasternal muscles. The evaluation was made in the dyspnea relief positions (sitting leaning forward, sitting leaning forward at a table, leaning forward with back against a wall, standing leaning forward, and high lying), seated erect, supine, and side lying. There were significant differences between the 8 positions (P < .001). There was no significant difference in muscle activation between sitting leaning forward and sitting leaning forward at a table position with analyzing post hoc test results (P > .99 for each muscle). However, muscle activation was lower in these 2 positions than in the other positions (P < .001 for each muscle). Muscle activation was greater in the supine position than in the other positions (P < .001 for each muscle). No difference was observed in muscle activation between the seated erect, leaning forward with back against a wall, standing leaning forward, high-lying, or side-lying positions (P > .05 for each muscle with a minimum P value of .09). The use of sitting leaning forward and sitting leaning forward at a table positions together with breathing control may help people with COPD to achieve more effective dyspnea relief and greater energy efficiency.

Energy expenditure and effort of patients with stroke during sit to stand: A pilot study

Background: Sit-to-stand (STS) is a mechanically demanding task. Little is known about the energy expenditure (EE) and the perceived effort of patients with stroke during STS.Objectives: The objectives of our study were to assess the perceived effort and EE of patients with stroke when moving from STS and to determine whether an association between actual energy expended and patient-perceived effort exists.Method: This descriptive cross-sectional pilot study assessed participants’ EE and perceived effort during STS, with a triaxial accelerometer and the modified Borg scale (MBS), respectively.Results: The team screened 428 individuals for potential inclusion, with nine participants (n = 5 female, 55.5%) meeting the criteria for our pilot study. Participants had a mean age of 52.77 (standard deviation [SD] ± 11.33) years, the majority had a haemorrhagic stroke (n = 6, 66.6%) and left hemiplegia (n = 6, 66.6%), and they were assessed 9.11 (SD ± 6.57) days post-stroke. The mean EE during STS was 2.82 (SD ± 1.9) kCal. Most participants (n = 7, 77.77%) perceived STS as more than a ‘moderate’ effort on the MBS. The correlation coefficient between the metabolic equivalent of task (METs) and MBS was r = 0.34 (p = 0.38).Conclusion: Our study found a fair positive correlation between METs and MBS for patients with stroke during STS.Clinical implications: The increased EE shown can be a key point for rehabilitation to lessen the extent of EE during STS. Further research is warranted.

The Acute: Chronic Workload Ratio and Injury Risk in Semiprofessional Football Players.

The purpose of this study was to analyze the association and predictive capacity between the acute:chronic workload ratio (ACWR) and non-contact injuries in a semiprofessional football team. Seventeen football or soccer players from a Spanish Third Division football team participated voluntarily in this study. A prospective longitudinal study was developed during the 2020/2021 season. Twenty-four weeks were analyzed from October to March, including a regenerative microcycle due to the absence of competition during Christmas. Rate of perceived exertion (RPE) and session-rate of perceived exertion (sRPE) were registered for every training and game session. Afterward, acute and chronic workloads were calculated, and ACWR was subsequently derived from them. Furthermore, non-contact injuries were registered during the period mentioned. The main findings were that there is a poor correlation between the ACWR and non-contact injuries (r=0.069 (p<0.05)), and the use of the ACWR by itself is insufficient to predict the occurrence of non-contact injuries in a semiprofessional football team. Consequently, the ACWR is not an useful predictive tool for injuries in semiprofessional football teams.

Exoskeletal-Assisted Walking During Acute Inpatient Rehabilitation Enhances Recovery for Persons with Spinal Cord Injury-A Pilot Randomized Controlled Trial.

Spinal cord injury (SCI) negatively impacts individuals' functional independence, and motor and sensory function. Intense walking training has been shown to facilitate recovery for individuals with chronic SCI. Powered robotic exoskeletons provide therapists with a tool that allows them to conduct walking training with less therapist effort as compared to conventional walking training. Exoskeletal-assisted walking (EAW) has been studied in the chronic SCI population with preliminary reports showing benefits in mobility, health, and quality-of-life outcomes. However, few reports have studied EAW's benefits in the acute (<90 days post) SCI population at a time when neural plasticity is most dynamic and modifiable. The purpose of the study was to conduct a pilot randomized controlled trial (RCT) to understand the effects of incorporated EAW in acute inpatient rehabilitation (AIR) for individuals with SCI on functional, motor, and sensory recovery. The study outcomes included the Spinal Cord Independence Measure (SCIM) III and International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) motor and sensory scores that were assessed by unblinded assessors. We also recorded EAW session data, including adverse events, walking and up time, step counts, Borg Rating of Perceived Exertion (RPE), and compliance with scheduled EAW training. From August 2019 to July 2022, 16 participants completed the AIR with incorporated EAW, and 12 completed the standard AIR, all with SCI and preserved leg function within 90 days post-injury. During each session, the AIR with incorporated EAW group averaged 34.3 (±9.4) min of up time, 25.4 (±7.7) min of walk time, and 536 (±157) steps. Analysis via two-by-two mixed-effects models showed significant increases in the SCIM total score and ISNCSCI total motor and sensory scores over time for the AIR with incorporated EAW group [SCIM total score: F(1, 26) = 5.59, p = 0.03; total motor score: F(1, 26) = 8.06, p < 0.01; total sensory score: F(1, 19.2) = 5.08, p = 0.04], outperforming the standard AIR group. The AIR with incorporated EAW group showed 13, 14, and 22 points higher changes in the SCIM total score, total motor score, and total sensory score (respectively) by discharge compared with the standard AIR group. Incorporating EAW into AIR may facilitate functional, motor, and sensory recovery for individuals with SCI during AIR better than standard AIR. However, the study had a limited sample size. Further studies are needed to clarify the effects of EAW in AIR.

Surgical management of omega deformity in a patient with neurofibromatosis type 1: a case report.

To describe the surgical treatment in a patient with a partial omega deformity in the thoracic spine with neurofibromatosis type 1. The patient was a 55-year-old man with an omega deformity, which is defined as a curvature in which the end vertebra is positioned at the level of, above, or below the apical vertebra (i.e., a horizontal line bisecting it). We performed halo gravity traction (HGT) for 7weeks, followed by posterior spinal instrumented nearly equal in situ fusion from T2-L5 with three femoral head allografts and a local bone autograft. We avoided reconstruction of the thoracic anterior spine because of his severe pulmonary dysfunction. HGT improved the % vital capacity from 32.5 to 43.5%, and improved the Cobb angle of the kyphosis from > 180° before traction to 144° after traction. The Cobb angle of kyphosis and scoliosis changed from > 180° preoperatively to 155° and 146°, respectively, postoperatively, and 167° and 156°, respectively, at final follow-up. His postoperative respiratory function deteriorated transiently due to bilateral pleural effusions and compressive atelectasis, which was successfully treated with a frequent change of position and nasal high flow for 1week. At final follow-up, his pulmonary function improved from 0.86 to 1.04L in VC, and from 32.5 to 37.9% in %VC. However, there was no overall improvement in preoperative distress following surgery, although his modified Borg scale improved from 3 preoperatively to 0.5 postoperatively. One month after discharge, he felt worsening respiratory distress (SpO2:75%) and was readmitted for pulmonary hypertension for 2months. He was improved by non-invasive positive pressure ventilation (biphasic positive airway pressure) for 1week, medication and daily lung physiotherapy. Thereafter, he has been receiving permanent daytime (0.5L/min) and nighttime (2L/min) oxygen therapy at home. A solid arthrodesis through the fusion area was confirmed on computed tomography. However, the kyphosis correction loss was 12° (i.e., 155°-167°), while the scoliosis correction loss was 10° (i.e., 146°-156°) at 2years of recovery. We suggest that nearly equal in situ fusion is a valid option for preventing further deformity deterioration and avoiding fatal complications.

The relationship between prescribed ratings of perceived exertion and force production in repeated isometric contractions

Ratings of perceived exertion (RPE) are frequently used to monitor and prescribe exercise intensity. However, studies examining the shape and robustness of how feelings of effort map onto objective outputs are limited and report inconsistent results. To address this, we investigated whether (1) producing isometric forces according to RPE levels reliably leads to differences in force output, (2) if feelings of effort map linearly or non-linearly onto force output, and (3) if this mapping is robust when visual feedback and social facilitation are present. In a counterbalanced repeated measures design, N = 26 participants performed isometric handgrip contractions prescribed by ten levels of the Borg CR-10 scale. They did so either with or without the availability of concurrent visual feedback regarding their force production, and in the presence or absence of another person performing the same task simultaneously. We found that subjects reliably produced different force outputs that corresponded to each RPE level. Furthermore, concurrent visual feedback led to a linearization of force output, while in the absence of feedback, the produced forces could also be described by quadratic and cubic functions. Exploratory post-hoc analyses revealed that participants perceived moderate RPE levels to be more challenging to produce. By shedding light on the dynamic nature of the mapping between RPE and objective performance, our findings provide helpful insights regarding the utility of RPE scales.

Ultrasound in predicting improvement in dyspnoea after therapeutic thoracentesis in patients with recurrent unilateral pleural effusion

ABSTRACT Background In patients with recurrent pleural effusion, therapeutic thoracentesis is one way of relief. Correct prediction of which patients will experience relief following drainage may support the management of these patients. This study aimed to assess the association between ultrasound (US) characteristics and a relevant improvement in dyspnoea immediately following drainage. Methods In a prospective, observational study, patients with recurrent unilateral pleural effusion underwent US evaluation of effusion characteristics and diaphragm movement measured by M-mode and the Area method before and right after drainage. The level of dyspnoea was assessed using the modified Borg scale (MBS). A minimal important improvement in dyspnoea was defined as delta MBS ≥ 1. Results In the 104 patients included, 53% had a minimal important improvement in dyspnoea following thoracentesis. We found no association between US-characteristics, including diaphragm shape or movement (M-mode or the Area method), and a decrease in dyspnoea following drainage. Baseline MBS score ≥ 4 and a fully drained effusion were significant correlated with a minimal important improvement in dyspnoea (OR 3.86 (1.42–10.50), p = 0.01 and 2.86 (1.03–7.93), p = 0.04, respectively). Conclusions In our study population, US-characteristics including assessment of diaphragm movement or shape was not associated with a minimal important improvement in dyspnoea immediately following thoracentesis.

Are incremental exercise relationships between rating of perceived exertion and oxygen uptake or heart rate reserve valid during steady-state exercises?

Rating of perceived exertion (RPE) is considered a valid method for prescribing prolonged aerobic steady-state exercise (SSE) intensity due to its association with physiological indicators of exercise intensity, such as oxygen uptake (V̇O2) or heart rate (HR). However, these associations between psychological and physiological indicators of exercise intensity were found during graded exercise tests (GXT) but are currently used to prescribe SSE intensity even though the transferability and validity of the relationships found during GXT to SSE were not investigated. The present study aims to verify whether (a) RPE-HR or RPE-V̇O2 relations found during GXTs are valid during SSEs, and (b) the duration and intensity of SSE affect these relations. Eight healthy and physically active males (age 22.6 ± 1.2 years) were enrolled. On the first visit, pre-exercise (during 20 min standing) and maximal (during a GXT) HR and V̇O2 values were measured. Then, on separate days, participants performed 4 SSEs on the treadmill by running at 60% and 80% of the HR reserve (HRR) for 15 and 45 min (random order). Individual linear regressions between GXTs' RPE (dependent variable) and HRR and V̇O2 reserve (V̇O2R) values (computed as the difference between maximal and pre-exercise values) were used to predict the RPE associated with %HRR (RPEHRR) and %V̇O2R (RPEV̇O2R) during the SSEs. For each relation (RPE-%HRR and RPE-%V̇O2R), a three-way factorial repeated measures ANOVA (α=0.05) was used to assess if RPE (dependent variable) was affected by exercise modality (i.e., RPE recorded during SSE [RPESSE] or GXT-predicted), duration (i.e., 15 or 45 min), and intensity (i.e., 60% or 80% of HRR). The differences between RPESSE and GXT-predicted RPE, which were assessed by evaluating the effect of modality and its interactions with SSE intensity and duration, showed no significant differences between RPESSE and RPEHRR. However, when RPESSE was compared with RPEV̇O2R, although modality or its interactions with intensity were not significant, there was a significant (p=0.020) interaction effect of modality and duration yielding a dissociation between changes of RPESSE and RPEV̇O2R over time. Indeed, RPESSE did not change significantly (p=0.054) from SSE of 15 min (12.1 ± 2.0) to SSE of 45 min (13.5 ± 2.1), with a mean change of 1.4 ± 1.8, whereas RPEV̇O2R decreased significantly (p=0.022) from SSE of 15 min (13.7 ± 3.2) to SSE of 45 min (12.4 ± 2.8), with a mean change of -1.3 ± 1.5. The transferability of the individual relationships between RPE and physiological parameters found during GXT to SSE should not be assumed as shown by the results of this study. Therefore, future studies modelling how the exercise prescription method used (e.g., RPE, HR, or V̇O2) and SSE characteristics (e.g., exercise intensity, duration, or modality) affect the relationships between RPE and physiological parameters are warranted.

Heel riser height influence on kinematics and muscle activity of ski mountaineering – A field based study

Introduction The ski binding plays an important role in ski mountaineering. When traveling uphill, the binding has an adjustable heel height known as the riser. Previous laboratory research reported joint kinematics and kinetics are influenced by riser height, however little is known about changes to muscle activity associated with differing joint motion. The purpose of this work was to assess riser height influence on kinematics and muscle activity at different slopes during on-snow skiing. Methods Three female and nine male recreational ski mountaineers (19-26 y) were tested on 5o and 16o gradients using no riser (0 cm) and riser (5.3 cm) at a submaximal 80% HRmax. Each subject used Backland 85 UL skis and Backland Bindings (Atomic Skis, Altenmarkt, Austria). Subjects skied for 6 min at each binding setting with the last 10 gait-cycles evaluating lower limb joint motion gathered from 2D-sagittal plane motion capture. Electromyography (EMG) collected unilaterally on the rectus femoris, biceps femoris, medial gastrocnemius and triceps brachii also. Results 5o slope: hip range of motion (ROM) decreased (p = .003), ankle ROM decreased (p = .005), stride length decreased (p = .004), rating of perceived exertion (RPE) increased (p = .02) for riser compared to no riser. At 16o slope: hip ROM decreased (p = .001), and RPE decreased (p = .004) for riser compared to no riser. HR, glide distance, velocity, EMG, and net mechanical efficiency were not different between riser heights on either slope. Discussion/Conclusion Lower body joint kinematics, step length and RPE varied significantly with riser height. Kinematic differences did not impact velocity or muscle activity when controlling pace. These results agree with previous findings showing minimal differences in EMG and HR while lower body kinematics and RPE changed with riser height.

Inhalation of hydrogen-rich gas before acute exercise alleviates exercise fatigue.

Hydrogen, as an antioxidant, may have the potential to mitigate fatigue and improve selected oxidative stress markers induced by strenuous exercise. This study focused on previously unexplored approach of pre-exercise inhalation of hydrogen-rich gas (HRG). Twenty-four healthy adult men first completed prelaboratories to determine maximum cycling power (Wmax) and maximum cycling time (Tmax). Then they were subjected to ride Tmax at 80% Wmax on cycle ergometers after inhaled HRG or placebo gas (air) for 60-minute in a double-blind, counterbalanced, randomized, and crossover design. The cycling frequency in the fatigue modelling process and the rating of perceived exertion (RPE) at the beginning and end of the ride were recorded. Before gas inhalation and after fatigue modeling, visual analog scale (VAS) for fatigue and counter-movement jump (CMJ) were tested, and blood samples were obtained. The results showed that compared to placebo, HRG inhalation induced significant improvement in VAS, RPE, the cycling frequency in the last 30 seconds, the ability to inhibit hydroxyl radicals, and serum lactate after exercise (p < 0.028), but not in CMJ height and glutathione peroxidase activit. In conclusions, HRG inhalation prior to acute exercise can alleviate exercise-induced fatigue, maintain functional performance, and improve hydroxyl radical and lactate levels.