Effects of Back Pressure on the Feasibility and Tolerability of Laryngeal Diadochokinetic Exercise: A Pilot Study.

BACKGROUND: The term vocal demand response refers to how speakers meet vocal demands. Vocal loading tasks with predetermined demand parameters (duration, pitch, loudness, etc) have been used in research to study the vocal demand response; these have historically consisted of loud sustained vowel and loud speech tasks. Tasks founded on laryngeal diadochokinesis (LDDK) may be viable alternatives, especially if demand parameters such as exercise-rest ratio and fluid back pressure are concurrently modulated. OBJECTIVES: To explore the effects of four fluid back pressure conditions (0, 5, 10, and 15 cm H2O) on several measures of subjective participant experience, feasibility, and tolerability during intervallic laryngeal diadochokinetic exercise. METHODS: Participants (n = 12) completed 15-minute trials of LDDK in 30-second rest and exercise intervals against four counterbalanced back pressure conditions: 0, 5, 10, and 15 cm H2O. The effects of back pressure on (1) ratings of perceived vocal exertion, (2) prevalence of adverse effects such as shortness of breath or lightheadedness, (3) subjective difficulty of sustaining LDDK, (4) number of exercise intervals completed, (5) rankings of participant-preferred back pressure levels, and (6) expert ratings of auditory-perceptual diadochokinetic strength were assessed descriptively. RESULTS: Perceived vocal exertion, lightheadedness, and subjective laryngeal diadochokinetic difficulty increased as back pressure increased. Number of intervals completed, auditory-perceptual diadochokinetic strength, and participant rankings of back pressure conditions, by contrast, decreased as back pressure increased. 0 and 5 cm H2O were the most preferred back pressure conditions overall. DISCUSSION: Fluid back pressure was feasible and broadly tolerated during 15-minute trials of vocal exercise. However, the transition from 5 → 10 cm H2O appeared to represent an inflection point in our results: a minority of participants did not tolerate exercise at 10 cm H2O, becoming a majority at 15 cm H2O. We conclude that fluid back pressure should be restricted to values between 0 and 10 cm H2O during LDDK.

Follow-up of Cardiopulmonary Responses Using Submaximal Exercise Test in Older Adults with Post-COVID-19.

Background: Data on cardiopulmonary fitness in older adults in the longer term after coronavirus disease 2019 (COVID-19) are of interest as the time required for the full recovery of physical fitness after COVID-19 remains unclear. Some studies have reported that patients do not recover physical fitness for up to 6 or 12 months after COVID-19, whereas other studies have observed full recovery after 12-months. Therefore, this study evaluated and compared the cardiopulmonary responses induced by the 6-minute walk test (6MWT) and 1-minute sit-to-stand-test (STST) results at 3, 6, and 12 months in older adults with and without COVID-19. Methods: This study included 59 older adults with and without a history of COVID-19. The cardiopulmonary response parameters including heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse oxygen saturation (O2 sat), rate of perceived exertion (RPE), and leg fatigue were evaluated in the participants after 6MWT and 1-min-STST assessments. Results: Post-COVID-19, older adults showed statistically significant differences in HR, SBP, DBP, O2 sat, RPE, leg fatigue, 6MWT time, and 1-min-STST step numbers at 3, 6, and 12 months (P < 0.001). Moreover, older adults showed statistically significant differences in HR, SBP, DBP, RPE, leg fatigue, O2 sat, and 6MWT distance at 3 months post-COVID-19 compared with those in older adults without COVID-19 (P < 0.001). Conclusion: While older adults showed recovery of cardiopulmonary response parameters according to 6MWT and 1-min-STST findings at the 12-month follow-up post-COVID-19, these results of these measurements did not return to the values observed in older adults without COVID-19.

Effects of Different Visual Flow Velocities on Psychophysiological Responses During Virtual Reality Cycling.

INTRODUCTION: Virtual reality cycling (VRC) is simulated outdoor cycling with changes in scenery in virtual reality (VR) with rotating ergometer pedals. The speed at which the scenery changes, which is the visual flow velocity, can shift according to the same pedal rotation speed. OBJECTIVES: This study investigated the effects of different visual flow velocities on the psychophysiological responses of cyclists using the VRC. METHODS: Participants were asked to cycle for 20 min at 30% of their maximum exercise load under four conditions: (1) bicycle ergometer without VR (control), (2) VRC at normal visual flow velocity (VRC-normal), (3) VRC at 0.5 times the visual flow velocity of VRC-normal (VRC-slow), and (4) VRC at 1.5 times the visual flow velocity of VRC-normal (VRC-fast). The order of the four conditions was randomized in a counterbalanced design. The heart rate and rating of perceived exertion were recorded during the exercise. Participants graded their enjoyment of the task using the physical activity enjoyment scale (PACES). The measured data were analyzed by comparing the visual flow velocity conditions (VRC-slow, VRC-normal, and VRC-fast), and comparing the VRC and bicycle ergometer (VRC-normal and control). RESULTS: A total of 24 participants were enrolled in the study. There was a significant main effect observed in the PACES score (F(2,46)=20.129, p<0.001, partial η2=0.467). In the post-hoc test for the PACES, significant differences were found in the following combinations: VRC-normal > VRC-slow (p=0.005); VRC-fast > VRC-normal (p=0.003); and VRC-fast > VRC-slow (p<0.001). In the modified Borg scale for lower-limb fatigue, there were significant differences in time factor (F(2,46)=134.048, p<0.001, partial η2=0.854) and interaction effects (F(4,92)=3.156, p=0.018, partial η2=0.121). In the post-hoc test for the modified Borg scale, significant trends were found in the following combinations: VRC-normal > VRC-fast (p=0.068) and VRC-slow > VRC-fast (p=0.083). CONCLUSION: The results suggest that a slower visual flow velocity may reduce the enjoyment of exercise, whereas a faster visual flow velocity may make the exercise feel less fatigued and more enjoyable.

Case study: Evaluating deep-water start techniques and training demands in seated slalom waterskiing for an athlete with paraplegia.

Purpose: Recreational and competitive slalom waterskiing is increasingly popular among individuals with spinal cord injuries (SCI), particularly for those with paraplegia using sit-skis. A key component of slalom skiing is the deep-water start (DWS), yet little is known about the physiological and physical demands of this activity when the athlete is seated. This study aims to fill this gap by focusing on the training requirements for a seated slalom athlete. Materials and methods: Focusing on a young male athlete with paraplegia, this case study evaluates the effectiveness and efficiency of traditional (TDWS) and alternative (ADWS) DWS techniques during seated slalom waterskiing sessions. It assesses internal training load (TL) through heart rate (HR) zones and session rating of perceived exertion (sRPE), alongside pre- and post-session handgrip strength measurements to gauge peripheral muscle fatigue. Results and conclusions: Performing the ADWS, achieving a full success rate, proved more effective but slightly more time-consuming than TDWS, which had limited success. HR during DWS maneuvers ranged from 63.2 to 81.3% of maximal HR, with most sessions occurring below the ventilatory threshold, thus perceived as hard effort. A moderate yet non-significant correlation was found between HR and sRPE-based TL. A significant reduction in handgrip strength post-session underscores the activity's demands. These insights illuminate the technical, physiological, and physical challenges in mastering DWS for seated slalom athletes with SCI, providing valuable guidance for the development of tailored training programs and techniques in this sport.

Preventing Exertional Heat Stroke in Football: Time for a Paradigm Shift.

CONTEXT: Among American sports, football has the highest incidence of exertional heat stroke (EHS), despite decades of prevention strategies. Based on recent reports, 100% of high school and college EHS football fatalities occur during conditioning sessions. Linemen are the at-risk population, constituting 97% of football EHS deaths. Linemen heat up faster and cool down slower than other players. EVIDENCE ACQUISITION: Case series were identified from organized, supervised football at the youth, high school, and collegiate levels and compiled in the National Registry of Catastrophic Sports Injuries. Sources for event occurrence were media reports and newspaper clippings, autopsy reports, certificates of death, school-sponsored investigations, and published medical literature. Articles were identified through PubMed with search terms "football," "exertional heat stroke," and "prevention." STUDY DESIGN: Clinical review. LEVEL OF EVIDENCE: Level 5. RESULTS: Football EHS is tied to (1) high-intensity drills and conditioning that is not specific to individual player positions, (2) physical exertion as punishment; (3) failure to modify physical activity for high heat and humidity, (4) failure to recognize early signs and symptoms of EHS, and (5) death when cooling is delayed. CONCLUSION: To prevent football EHS, (1) all training and conditioning should be position specific; (2) physical activity should be modified per the heat load; (3) understand that some players have a "do-or-die" mentality that supersedes their personal safety; (4) never use physical exertion as punishment; (5) eliminate conditioning tests, serial sprints, and any reckless drills that are inappropriate for linemen; and (6) consider air-conditioned venues for linemen during hot practices. To prevent EHS, train linemen based on game demands. STRENGTH-OF-RECOMMENDATION TAXONOMY: n/a.

Sex- and age-adjusted reference values for dynamic inspiratory constraints during incremental cycle ergometry.

Activity-related dyspnea in chronic lung disease is centrally related to dynamic (dyn) inspiratory constraints to tidal volume expansion. Lack of reference values for exertional inspiratory reserve (IR) has limited the yield of cardiopulmonary exercise testing in exposing the underpinnings of this disabling symptom. One hundred fifty apparently healthy subjects (82 males) aged 40-85 underwent incremental cycle ergometry. Based on exercise inspiratory capacity (ICdyn), we generated centile-based reference values for the following metrics of IR as a function of absolute ventilation: IRdyn1 ([1-(tidal volume/ICdyn)] x 100) and IRdyn2 ([1-(end-inspiratory lung volume/total lung capacity] x 100). IRdyn1 and IRdyn2 standards were typically lower in females and older subjects (p<0.05 for sex and age versus ventilation interactions). Low IRdyn1 and IRdyn2 significantly predicted the burden of exertional dyspnea in both sexes (p<0.01). Using these sex and age-adjusted limits of reference, the clinician can adequately judge the presence and severity of abnormally low inspiratory reserves in dyspneic subjects undergoing cardiopulmonary exercise testing.

Force and Neuromuscular Responses During a Handgrip Hold to Failure Anchored to a Moderate Perceptual Intensity in Males.

OBJECTIVES: The current study investigated performance fatigability (PF) and time course of changes in force, electromyographic amplitude (EMG AMP) and frequency (EMG MPF), and neuromuscular efficiency (NME) during a sustained, isometric, handgrip hold to failure (HTF) using the rating of perceived exertion (RPE)-Clamp Model. METHODS: Twelve males performed a handgrip HTF anchored to RPE=5. The time to task failure (Tlim), force (N), EMG AMP and MPF, and NME (normalized force/ normalized EMG AMP) were recorded. Analyses included a paired samples t-test for PF at an alpha of p<0.05, 1-way repeated measures ANOVA across time and post-hoc t-tests (p<0.0025) for force, EMG AMP and MPF, and NME responses. RESULTS: The PF (pre- to post- maximal force % decline) was 38.2±11.5%. There were decreases in responses, relative to 0% Tlim, from 40% to 100% Tlim (force), at 30%, 60%, and 100% Tlim (EMG AMP), from 10% to 100% Tlim(EMP MPF), and from 50% to 65%, and 80% to 100% Tlim (NME) (p<0.0025). CONCLUSIONS: The RPE-Clamp Model in this study demonstrated that pacing strategies may be influenced by the integration of anticipatory, feedforward, and feedback mechanisms, and provided insights into the relationship between neuromuscular and perceptual responses, and actual force generating capacity.

Comparison of distance covered, physiological cost, and perceived exertion in four six-minute walk test protocols.

Objective: There is evidence that indicates that the Walked Distance (WD) in the 6-Minute Walk Test (6MWT) would be sensitive to the type of track and encouragement. The aim of study was compared the impact of track type and verbal encouragement provided in the 6MWT on WD, physiological cost, perceived exertion, and gait efficiency in healthy young adults unfamiliar with the test. Method: WD, heart rate, subjective sensation of dyspnea (SSD), and fatigue (SSF) were measured in four 6MWT protocols: i) 30 m linear track and protocolized encouragement (LT + PE), ii) 30 m linear track and constant encouragement (LT + CE), iii) 81 m elliptical track and protocolized encouragement (ET + PE), and iv) 81 m elliptical track and constant encouragement (ET + CE). In addition, the Gait Efficiency Index (GIE) associated with physiological cost, dyspnea and fatigue was calculated and compared between the different protocols. Results: The WD was significantly higher in the ET + CE protocol. The percentage of the heart rate reserve used (%HRRu) at minute 6 was higher in the ET + CE protocol. The SSD and SSD had difference in startup time between the protocols. The GEI was higher in %HRRu, SSD, and SSF for the ET + CE protocol. Conclusion: The ET + CE protocol showed a significant increase in WD during the 6MWT in healthy young adults. Although it obtained the highest physiological cost, it did not present perceptual differences when entering cardiopulmonary assessment windows relevant to a more efficient test for the participant. It is advisable to discuss, based on the findings, the fundamental objective of the 6MWT and national and international recommendations to achieve a result as close as possible to the real maximal effort.

The Use of a Just Noticeable Difference Approach to Improve Perceptual Acuity Ability in Male Runners.

We were interested in micro-variations in an athlete's psychophysical state that separate peak exertion from physiological collapse. Thus, we measured perceptual acuity in runners using a classic psychophysical approach, the just noticeable difference (JND) on two standard stimuli runs at treadmill speed corresponding to 70%VO2max and 80%VO2max. Thirty-four male runners (M age = 35.26, SD = 7.33 years) first performed a maximal treadmill test to determine the speed of a standard exercise bout for the JND trials. The JND trials consisted of four 5-minute running bouts on a treadmill with 5-minute rests between bouts. For bouts 1 and 3, participants ran at the standard stimuli pace, but for bouts 2 and 4, they adjusted their speeds to achieve a level of exertion at a JND above/below the SS. They achieved differences in the final 30 seconds of the VO2 between each JND bout and the previous standard stimuli at just above (JND-A) and just below (JND-B) the JND perceived exertions. We used a Generalized Linear Model analysis to compare the JND-A and JND-B within and between ventilatory threshold groups (lower/higher) in absolute and relative VO2 and in terms of the total JND magnitude. The magnitude of JND-A was greater than that of JND-B at 70%VO2max and 80%VO2max in absolute units (70%VO2 Δ = 2.62; SE = 0.37; p < .001; 80%VO2 Δ = 1.67; SE = 0.44; p = .002) and in relative units (70%VO2max Δ = 4.70; SE = 0.66; p < .001; 80%VO2max Δ = 2.96; SE = 0.80; p = .002). The total magnitude was greater in the 70%VO2max trial than 80%VO2max in absolute units (70%VO2 M = 3.78, SE = 0.31 mL·kg-1·min-1; 80%VO2 M = 2.62, SE = 0.37 mL·kg-1·min-1; p = .020) and in relative units (70%VO2max M = 6.57, SE = 0.53%VO2max; 80%VO2max M = 4.71, SE = 0.64%VO2max; p = .030). The JND range narrowed when physiologic demand increased, for both physical (speed) and psychological (RPE) variables.

[Physiological assessment and management of post-COVID patients with normal cardiopulmonary imaging and functional tests]. / Valoración fisiológica y manejo de pacientes post-COVID con pruebas funcionales cardiopulmonares y de imagen normales.

OBJECTIVE: Contributing to elucidate the pathophysiology of dyspnoea and exertion intolerance in post-COVID syndrome patients with normal cardiopulmonary imaging and functional tests at rest, while determining their fitness and level of endurance in order to individualize working parameters for physical rehabilitation. MATERIAL AND METHODS: After an anamnesis and clinical examination at rest, 27 subjects (50±11.9 years) (14 women) with post-COVID syndrome of more than 6 months of evolution performed a continuous maximal-incremental graded cardiopulmonary exercise test (CPET) with breath-by-breath gas-exchange monitoring and continuous ECG registration, on an electromagnetically braked cycle ergometer. The values obtained were compared with those of reference, gender or controls, using the Chi-square, t-Student or ANOVA test. RESULTS: The clinical examination at rest and the CPET were clinically normal and without adverse events. Reasons for stopping exercise were leg discomfort. It is only worth noting a BMI=29.9±5.8kg/m2 and a basal lactate concentration of 2.1±0.7mmol/L. The physiological assessment of endurance showed the following results relative to predicted VO2máx: 1)peakVO2=80.5±18.6%; 2)VO2 at ventilatory threshold1 (VO2VT1): 46.0±12.9%; 3)VO2VT2: 57.2±16.4%; 4)working time in acidosis: 5.6±3,0minutes; and 5)maximum lactate concentration: 5.1±2.2mmol/L. CONCLUSIONS: The CPET identified limited aerobic metabolism and early increase in glycolytic metabolism as causes of dyspnoea and exercise intolerance, determined fitness for physical rehabilitation, and individualized it based on the level of endurance.

Typical Exertional Angina With No Angiographic Coronary Artery Disease.

Cardiac syndrome X (CSX) is a cardiac condition that is a diagnosis of exclusion. Patients usually present with terrible chest pains suggestive of myocardial infarction, but angiogram imaging shows no occlusion in the coronary vessels that would be suggestive of coronary artery disease. CSX is more commonly seen in women, but this case report demonstrates a different clinical presentation of CSX in a young, otherwise healthy male patient. The 38-year-old male patient presented to the emergency room with chest discomfort radiating to the left arm and to the left jaw. The chest pain started after the patient went for a jog, with the pain lasting for a couple of hours. The electrocardiogram (ECG) was abnormal, showing nonspecific ST changes and unremarkable troponin levels. The patient underwent a coronary angiogram, which was unremarkable. Three years later, the patient presented once more with chest heaviness that occurred again after going for a run. The patient's troponins were unremarkable, and an ECG test showed a new onset of AV block. Due to the ongoing chest pain, the patient received another coronary angiogram. This showed that the coronary vessels had no indications of occlusion. The patient was discharged and scheduled to follow up with their cardiologist for an extensive discussion about medications for their condition. This case report should bring awareness of the classical presentation of this disease in an uncommon population group and a way to identify this syndrome once exclusions have been made on previous hospitalizations.

Effects of two external cooling strategies on physiological and perceptual responses of athletes with tetraplegia during and after exercise in the heat.

Athletes with tetraplegia may experience marked hyperthermia while exercising under environmental heat stress due to their limited ability to dissipate heat through evaporative means. This study investigated the effectiveness of two external cooling strategies (i.e., spraying water onto the body surface or using a cooling vest) on physiological and perceptual variables in tetraplegic athletes during and after an aerobic exercise session in a hot environment. Nine male wheelchair rugby players performed an incremental test to determine their maximum aerobic power output. After that, they were subjected to three experimental trials in a counter-balanced order: control (CON, no body cooling), cooling vest (CV), and water spraying (WS). During these trials, they performed 30 min of a submaximal exercise (at 65% of their maximum aerobic power) inside an environmental chamber set to maintain the dry-bulb temperature at 32 °C. The following variables were recorded at regular intervals during the exercise and for an additional 30 min following the exertion (i.e., post-exercise recovery) with the participants also exposed to 32 °C: body core temperature (TCORE), skin temperature (TSKIN), heart rate (HR), rating of perceived exertion (RPE), thermal comfort (TC), and thermal sensation (TS). While exercising in CON conditions, the tetraplegic athletes had the expected increases in TCORE, TSKIN, HR, RPE, and TC and TS scores. HR, TC, and TS decreased gradually toward pre-exercise values after the exercise, whereas TCORE and TSKIN remained stable at higher values. Using a cooling vest decreased the temperature measured only on the chest and reduced the scores of RPE, TC, and TS during and after exercise but did not influence the other physiological responses of the tetraplegic athletes. In contrast, spraying water onto the athletes' body surface attenuated the exercise-induced increase in TSKIN, led to lower HR values during recovery, and was also associated with better perception during and after exercise. We conclude that water spraying is more effective than the cooling vest in attenuating physiological strain induced by exercise-heat stress. However, although both external cooling strategies do not influence exercise hyperthermia, they improve the athletes' thermal perception and reduce perceived exertion.

A Comparative Analysis of Acute Physiological and Perceptual Responses in Whole-Body and Ergometer-Based High-Intensity Interval Training Protocols.

The primary aim of the present investigation was to compare the acute physiological and perceptual responses between two modes of interval training using a randomized crossover design. More specifically, eleven young adult participants (23 ± 4 years, 77 ± 13 kg, 178 ± 7 cm) performed two protocols: one composed of whole-body calisthenics exercises and another on a cycle ergometer. Both protocols encompassed eight 20 s bouts at intensities equivalent to all-out (HIIT-WB) and 170% of the maximal power output (HIIT-C), respectively, interspersed with 10 s of passive rest. The peak and average heart rate, the rating of perceived effort, and blood lactate, creatine kinase, and lactate dehydrogenase concentrations were measured. Aside from blood lactate (HIIT-WB = 9.4 ± 1.8 mmo/L; HIIT-C = 12.5 ± 2.5 mmol/L, p < 0.05) and the rating of perceived exertion (HIIT-WB = 8.8 ± 0.9; HIIT-C = 9.6 ± 0.5, p < 0.05), physiological responses did not significantly differ between protocols (all p > 0.05), with high average heart rate values (HIIT-WB = 86 ± 6% HRmax; HIIT-C = 87 ± 4% HRmax) and a low magnitude of muscle damage, as inferred by CK and LDH concentrations (HIIT-WB = 205.9 ± 56.3 and 203.5 ± 72.4 U/L; HIIT-C = 234.5 ± 77.1 and 155.1 ± 65.3 U/L), respectively. It can be concluded that both protocols elicit vigorous heart rate responses and a low magnitude of muscle damage and, therefore, appear as viable alternatives to improve aerobic fitness. The inclusion of a whole-body HIIT protocol may be an interesting alternative for training prescription in relation to more common interval training protocols.

Use of Osteopathic Manipulative Treatment for the Management of Pectus Excavatum: A Single Case Study.

Pectus excavatum (PE) is a congenital defect that presents with an anterior depression of the chest wall, which can impact cardiopulmonary function. A 25-year-old hypermobile male presented with a history of PE and chronic dyspnea on exertion, chronic cough, and intermittent chest wall pain. This study explores osteopathic manipulative treatment (OMT) as a possible alternative to improve symptoms associated with PE. Osteopathic structural exam (OSE), volumetric measurements of the thoracic cavity, vitals, and pulmonary function tests were evaluated at baseline and after OMT. The patient was treated with 14 weeks of weekly OMT for his exertional dyspnea, cough, and chest wall pain. Somatic dysfunctions were addressed through OMT, which all improved by the end of the 14-week treatment. Notably, the excursion at the sternal angle increased by threefold after complete treatment. The patient reported subjective improvement in all symptoms, with durable improvement in chest wall pain at 10 months after cessation of treatment. The application of OMT can help alleviate symptoms of pectus excavatum and aid in the management of patients who have not received surgical interventions.

Rapidly Progressive Apical Hypertrophic Cardiomyopathy: Not Everything is What It Seems.

Apical hypertrophic cardiomyopathy (HCM) is a rare variant of HCM. A 43-year-old female with a past medical history significant for hypertension and kidney transplantation presented with recurrent syncopal episodes and dyspnea on exertion. Electrocardiogram showed characteristic diffuse giant T-waves inversion, and cardiac magnetic resonance showed HCM with circumferential apical thickening. This case highlights the rapid development of apical HCM and its challenging diagnostic characteristics.

Rating of Perceived Exertion: A Large Cross-Sectional Study Defining Intensity Levels for Individual Physical Activity Recommendations.

BACKGROUND: Physical inactivity is a growing risk factor worldwide, therefore getting people into sports is necessary. When prescribing physical activity, it is essential to recommend the correct training intensities. Cardiopulmonary exercise testing (CPX) enables precise determination of individuals' training intensities but is unavailable for a broad population. Therefore, the Borg scale allows individuals to assess perceived exertion and set their intensity easily and cost-efficiently. In order to transfer CPX to rating of perceived exertion (RPE), previous studies investigated RPE on specific physiological anchors, e.g. blood lactate (bLa) concentrations, but representativeness for a broad population is questionable. Some contradictory findings regarding individual factors influencing RPE occur, whereas univariable analysis has been performed so far. Moreover, a multivariable understanding of individual factors influencing RPE is missing. This study aims to determine RPE values at the individual anaerobic threshold (LT2) and defined bLa concentrations in a large cohort and to evaluate individual factors influencing RPE with multivariable analysis. METHODS: CPX with bicycle or treadmill ergometer of 6311 participants were analyzed in this cross-sectional study. RPE values at bLa concentrations 2 mmol/l, 3 mmol/l, 4 mmol/l, and LT2 (first rise in bLa over baseline + 1.5 mmol/l) were estimated by spline interpolation. Multivariable cumulative ordinal regression models were performed to assess the influence of sex, age, type of ergometry, VO2max, and duration of exercise testing on RPE. RESULTS: Median values [interquartile range (IQR)] of the total population were RPE 13 [11; 14] at 2 mmol/l, RPE 15 [13; 16] at 3 mmol/l, RPE 16 [15; 17] at 4 mmol/l, and RPE 15 [14; 16] at LT2. Main influence of individual factors on RPE were seen especially at 2 mmol/l: male sex (odds ratio (OR) [95%-CI]: 0.65 [0.587; 0.719]), treadmill ergometry (OR 0.754 [0.641; 0.886]), number of stages (OR 1.345 [1.300; 1.394]), age (OR 1.015 [1.012; 1.018]), and VO2max (OR 1.023 [1.015; 1.030]). Number of stages was the only identified influencing factor on RPE at all lactate concentrations/LT2 (3 mmol/l: OR 1.290 [1.244; 1.336]; 4 mmol/l: OR 1.229 [1.187; 1.274]; LT2: OR 1.155 [1.115; 1.197]). CONCLUSION: Our results suggest RPE ≤ 11 for light intensity, RPE 12-14 for moderate intensity, and RPE 15-17 for vigorous intensity, which slightly differs from the current American College of Sports Medicine (ACSM) recommendations. Additionally, we propose an RPE of 15 delineating heavy and severe intensity domain. Age, sex, type of ergometry, duration of exercise, and cardiopulmonary fitness should be considered when recommending individualized intensities with RPE, primarily at lower intensities. Therefore, this study can be used as a new guideline for prescribing individual RPE values in the clinical practice, predominantly for endurance type exercise.

Can mental fatigue affect perception of barbell velocity in resistance training?

Perception of Velocity (PV) is the ability to estimate single repetition velocity during resistance training (RT) exercises. The main purpose of the study was to evaluate the effects of Mental Fatigue (MF) on the accuracy of barbell PV. The secondary aims were to evaluate whether MF affected RT performance and ratings of perceived exertion (RPE; OMNI-RES) in the back squat. Twenty-four (14 Females, 10 Males) resistance-trained participants underwent 2 familiarization sessions and 1RM test for the back squat. In two separate sessions, PV was tested for light, medium, and heavy loads in 2 conditions in random order: at rest (REST) and in MF condition (POST-MF) induced by previous incongruent Stroop color-word task. MF and Motivation were assessed through visual analog scales (VAS; 0-100) before and after the Stroop task. For each load subjects performed 2 repetitions and reported the RPE value. Mean propulsive velocity (Vr) of the barbell was recorded with a linear encoder, while the perceived velocity (Vp) of the subjects was self-reported using the Squat-PV scale. The PV accuracy was calculated through the delta score (ds: Vp-Vr). Following the Stroop task MF increased significantly (p < 0.001; F (1, 23) = 52.572), while motivation decreased (p < 0.05; F (1, 23) = 7.401). Ds, Vr, and RPE did not show significant differences between conditions (p > 0.05) for the three loads analyzed. MF induced by previous demanding cognitive task did not affect PV accuracy. Furthermore, subjects maintained unchanged both RT performance and RPE values associated with each load, even when mentally fatigued.

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

Background: 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. Methods: 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). Results: 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. Conclusion: 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.

Exertion induced rhabdomyolysis in both triceps muscles in a 36-year old woman: A case report.

Rhabdomyolysis is a condition, often caused by strenuous exercise, which can lead to acute kidney injury, severe electrolyte imbalances, coagulopathies, compartment syndromes, and even have a fatal outcome in a few cases. Recognition and management of fluid and electrolyte abnormalities is one of the first steps of treatment and key to a good outcome. We report a case of a 36-year old woman who was referred to the ER by her general practitioner with severe muscle tenderness to the upper arms and highly elevated creatine kinase (CK) serum levels. Initial ultrasound imagery showed a patent venous system but demonstrated a moderate edematous infiltration of the muscle bellies of both m. triceps. Additional magnetic resonance imagery showed a hyperintense signal in T2 in both triceps' muscles. Given the clinical presentation, the MRI-findings were consistent with a form of exertion-induced rhabdomyolysis of both triceps' muscles. The patient was admitted for administration of IV-fluids to prevent acute kidney injury. Symptoms resolved in a few days and new magnetic resonance imagery showed a regression of the subcutaneous soft tissue infiltration. The aim of this paper is to raise awareness about this diagnosis. If overlooked, severe complications as mentioned above can occur.

"Bilateral Hot Forearm Sign": Ingeminating the Pattern of Physiological Uptake of 18F-Fludeoxyglucose.

Exertion and exercise increase glucose metabolism within the skeletal muscles causing increased fludeoxyglucose (FDG) uptake on 18F-FDG positron emission tomography/computed tomography (PET/CT). Here, we present findings of 18F-FDG PET/CT in a patient with acute viral hepatitis A-induced liver failure with multiple foci of pyoderma and incessant itching resulting in increased FDG uptake in the muscles of the bilateral forearm, producing the "bilateral hot forearm sign."