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PubMed2002

A comparison of AME and CR100 for scaling perceived exertion.

In psychophysical studies of the relation between perceived magnitude and physical stimulus, interest has focused on the preciseness of growth functions. Very little interest has been devoted to natural levels of an "absolute" character and to the validity of direct measurements. In this article, the Category (C)-Ratio (R) (CR) scaling methodology, developed by Borg (1973, 1977, 1982) is presented together with a new CR scale: the CR100 scale. In an experiment on perceived exertion, CR100 was compared with Absolute Magnitude Estimation (AME). Perceived exertion has the advantage of having easily measured physiological variables that can function as validity criteria. 32 persons (16 men and 16 women) participated as subjects on two different occasions, and the presentation order was counterbalanced. Results from CR100 and AME could be described equally well with psychophysical functions. The exponents obtained with CR100 were n = 1.60 for women and n = 1.69 for men, and the corresponding exponents for AME were n = 1.60 for women and n = 1.46 for men (with a "noise" constant included in the function). ANOVA showed that CR100 could make the predicted differentiation between sexes, whereas AME could not. This drawback with AME was also found when using the methods to predict working capacity.

Adult↗
PubMed2003

Computer mouse use in two different hand positions: exposure, comfort, exertion and productivity.

The aim of this study was to determine whether there are differences in exposure, comfort, exertion and productivity between a neutral and a pronated hand position when using a computer mouse. Nineteen experienced VDU workers performed a standardised text editing task with each mouse hand position. The wrist positions and movements in the working arm were registered by an electrogoniometer and the muscle activity in the shoulder, two extensors in the forearm and the first dorsal interossei (FDI) was registered by electromyography. The subjects rated perceived exertion and comfort in work with each mouse hand position. Work with the neutral hand position, compared to the pronated, gave a decreased muscle activity in the extensors of the forearm and in the FDI and a trend indicating a decrease in the frequency of deviation movements in the wrist. At the same time, the subjects showed a decreased productivity and they rated less comfort in work with the neutral hand position.

Adult↗
PubMedDate not supplied

DUFS and DEFS: development, reliability and validity of the Dutch Fatigue Scale and the Dutch Exertion Fatigue Scale.

The purpose of this study among patients with chronic heart failure (n = 138) was to develop and test both the Dutch Fatigue Scale (DUFS) and the Dutch Exertion Fatigue Scale (DEFS). Psychometric testing of these scales included measurement of internal consistency, construct validity and criterion-related validity. Statistical analyses of both scales showed sufficient reliability and validity. The DUFS (scale coefficient H = 0.48; Rho = 0.80; KR-20 = 0.79) is suitable as a measurement instrument for the diagnosis of fatigue and makes it possible to compare results of fatigue on the level of groups of patients. The DEFS (scale coefficient H = 0.61; Rho = 0.91; Cronbach's alpha = 0.91) can be used in clinical practice for the measurement of patients' exertion fatigue.

Adult↗
PubMed1985

Significance of ST-segment and T wave changes in the resting electrocardiograms of patients with exertional angina, studied by exercise radionuclide angiocardiograms.

In order to investigate the clinical significance of ST-T changes in resting ECG in angina pectoris, symptom-limited ergometer exercise radionuclide angiocardiography with ECG was performed in 60 patients with exertional angina. In those with normal ECG at rest (Group N), left ventricular ejection fraction (EF) did not change during exercise (71 +/- 5% to 71 +/- 6%). In those with only ST change at rest (Group ST) and those with only T change at rest (Group T), EF decreased significantly during exercise (68 +/- 5% to 63 +/- 7%, p less than 0.01; 68 +/- 6% to 61 +/- 7%, p less than 0.001). In those with ST and T changes at rest (Group ST + T), EF was low at rest (58 +/- 11%) and decreased further at exercise (52 +/- 8%, p less than 0.001). In those whose negative or flat T wave became more negative during exercise, EF was low both at rest and at exercise. In conclusion, ST and T changes at rest in patients with exertional angina might suggest a depressed reserve of myocardial function for exercise.

Adult↗
PubMed1992

Perceived exertion and exercise intensity in children with or without structural heart defects.

To assess the ability of children with cardiac disease to quantify their effort during exercise with the Borg perceived exertion scale, and to determine the validity of the scale for use with children by comparing the ratings with direct measurements of exercise intensity, we exercised 36 children with various cardiac defects and 15 normal children to exhaustion with the Bruce treadmill protocol. The subjects were able to quantify exercise intensity, so perceived exertion ratings can be used to predetermine the level of exercise intensity in an unmonitored setting and may be useful in defining appropriate exercise programs.

Adolescent↗
PubMed1998

Cerebral hemorrhage complicating exertional heat stroke.

Exertional heat stroke may be complicated by mild neurological deficits, usually with complete convalescence. This may be associated with metabolic disorders inherent to hyperthermia such as a marked coagulopathy. We report a case of a previously healthy 20 year old male who died in the course of exertional heat stroke complicated by intracerebral hemorrhage.

Adult↗
PubMed1997

[Fatal acute liver failure: a rare complication of exertion-induced heat stroke].

Liver injury is a well-known complication of exertional heat stroke. However severe acute irreversible liver dysfunction is rarely associated. Persistent centrolobular hepatocellular necrosis without any regeneration remains very uncommon. We report a case of fatal acute liver failure occurring after exertional heat stroke. Despite the conventional symptomatic treatment, especially active cooling, the patient experienced multiple organ failure with brain death 6 days after his admission. In this case, a chronic treatment with neuroleptic and anticholinergic agents may be considered as a predisposing factor.

Adult↗
PubMed2003

Posture-dependent trunk extensor EMG activity during maximum isometrics exertions in normal male and female subjects.

Posture-dependent trunk function data are important for appropriate normalization of submaximal trunk exertions, and is also necessary to define a more precise and specific use for strength testing in the prevention and diagnosis of spinal disorders. The aim of the current study was to quantify maximal effort trunk muscle extensor activity and trunk isometric extension torque over a functional range of sagittal standing postures. Twenty healthy, young adult male and female subjects performed isometric extension tasks over a sagittal posture range of -20 degrees extension to +50 degrees flexion, in 10 degrees increments. Erector spinae muscle activity was recorded bilaterally at the level of L3 using surface EMG electrodes. Isometric trunk extension torque was measured using a trunk dynamometer. EMG and trunk torque differed significantly between genders, but there were no differences between male and female subjects when the data were normalized with respect to the upright posture. For the combined male and female population, upright posture normalized L3 EMG activity (EMGn) and trunk extension torque (Tn) increased 1.7-fold and 3.5-fold, respectively, over the 70 degrees range of sagittal postures examined. The ratio (Tn/EMGn) increased two-fold (0.83 to 1.67) from -20 degrees extension to +50 degrees flexion, indicating that the neuromuscular efficiency increases with flexion. Trunk extension torque normalized with respect to the upright posture was linearly and positively correlated (r = 0.59, P < 0.001) to similarly normalized L3 EMG activity. This relatively weak correlation suggests that trunk muscle synergism and/or intrinsic muscle length-tension relationships are also modulated by posture. This study provides data that can be used to estimate trunk extensor muscle function over a broad range of sagittal postures. Our findings indicate that appropriate postural normalization of trunk extensor EMG activity is necessary for studies where submaximal trunk exertions are performed over a range of upright postures.

Adult↗
PubMed1998

Cellular responses in exertion-induced skeletal muscle injury.

Muscle injury is a common result of muscle exertion caused by overload and over-activity. In this presentation, an attempt was made to discuss models of muscle injury which involve exertion but not excessive strain, although most functional activities of the extremities require some eccentric muscle actions. Muscle injury is characterized by cellular and extracellular matrix responses which appear to be common to all types of muscle trauma -- even in the absence of bleeding. Using tenotomy and functional over-load of the rat hindlimb muscles as examples, illustrations of several of these responses are presented and discussed.

Animals↗
PubMed2006

Exercise does not feel the same when you are overweight: the impact of self-selected and imposed intensity on affect and exertion.

OBJECTIVE: The lower rates of adherence to physical activity commonly found among overweight adults compared to their normal-weight counterparts might be due to the activity being experienced as more laborious and less pleasant, particularly when its intensity is prescribed (or imposed) rather than self-selected. DESIGN: Within-subject design, with two 20-min sessions of treadmill exercise, one at self-selected speed and one at imposed speed, 10% higher than the self-selected. SUBJECTS: A total of 16 overweight (BMI: 31 kg/m2) and 9 normal-weight (BMI: 22 kg/m2) previously sedentary but healthy women (age: 43 years). MEASUREMENTS: Heart rate, oxygen uptake relative to body weight, and ratings of perceived exertion and pleasure-displeasure were assessed every 5 min. RESULTS: The overweight women showed higher oxygen uptake and perceived exertion than the normal-weight women during both sessions. Although the two groups did not differ in ratings of pleasure-displeasure during the session at self-selected speed, only the overweight women showed a significant decline when the speed was imposed. CONCLUSIONS: Imposing a speed that is just 10% higher than what overweight women would have self-selected led to a significant decline in reported pleasure. Over time, this could diminish the enjoyment of and intrinsic motivation for physical activity, reducing adherence.

Adult↗
PubMed2002

Functional ability, perceived exertion and employment of the individuals with spinal cord lesion in Taiwan.

STUDY DESIGN: A survey on functional ability, perceived exertion, and employment was mailed to 190 individuals with spinal cord lesion. Analysis is based on the 91 completed replies. OBJECTIVES: To establish a database of individuals with spinal cord lesions and to assess the effectiveness of training programs designed to improve life quality and employment chances among the individuals with spinal cord lesion. SETTINGS: Subjects selected from the Spinal Cord Injury Association of the Republic of China (SCIAROC) and from the Asylum Center Spinal Cord Injury (ASCCI) in Taiwan. METHODS: Information was obtained from a survey sent to the subjects who are chosen randomly from the SCIAROC and from all the subjects through ACSCI training program. RESULTS: Respondents in ACSCI had a higher functional activity level and lower perceived exertion during activities than those in SCIAROC. The employment status is related to the functional independence and level of injury. CONCLUSION: The database provides information on functional and employment status of individuals with spinal cord lesion. The present study also demonstrates the efficacy of a vocational training program for individuals with spinal cord lesion in Taiwan.

Activities of Daily Living↗
PubMed1997

Influence of ingesting a solution of branched-chain amino acids on perceived exertion during exercise.

On two occasions, seven male endurance-trained cyclists performed exhaustive exercise on a cycle ergometer in the morning after they had performed a bout of exercise the preceding evening in an attempt to lower the muscle glycogen stores. The subjects exercised at a work rate corresponding to approximately 70% of their maximal oxygen uptake for 60 min, followed by another 20 min of maximal exercise. During exercise the subjects were given either a solution of branched-chain amino acids (BCAAs) or flavoured water (placebo). Every 10 min during exercise the subjects rated their perceived exertion and mental fatigue on two different Borg scales. During the 60 min exercise at a given work rate the subjects ratings of perceived exertion when they were given BCAAs were 7% lower, and their ratings of mental fatigue were 15% lower than when they were given placebo. In addition, the performance in the colour task of Stroops Colour Word Test performed after exercise was improved when BCAAs had been ingested during exercise, compared with the results from the placebo trial. There was no difference in the physical performance between the two trials measured as the amount of work done during the last 20 min of exercise when the subjects performed at their maximum. The plasma concentration ratio of free tryptophan/BCAAs, which increased by 45% during exercise and by 150% 5 min after exercise in the placebo trial, remained unchanged or even decreased when BCAAs were ingested.

Adult↗
PubMed2000

A case of cytophagic histiocytic panniculitis associated with exertional rhabdomyolysis.

An 18-year-old man who suffered from panniculitis involving the entire left lower limb after exertional rhabdomyolysis is reported. A high fever (>39 degrees C) and leukocytosis (>20,000/microL) persisted for 1 week, and his general status deteriorated rapidly into pre-disseminated intravascular coagulation, complicated by pleural effusion and prolonged clotting time. His condition was dramatically improved by steroid pulse therapy and he has remained in good health for the 20 months since discharge. Histologic examination of subcutaneous tissue from the swollen left lower limb revealed pleomorphic small, medium or large lymphocytes, macrophages and neutrophils infiltrating the edematous subcutaneous adipose tissue in a lobular panniculitis-like pattern. The majority of inflammatory cells were T lymphocytes, with equal proportions of CD4+ and CD8+ cells. As polymerase chain reaction did not show bands suggesting T cell receptor gamma gene rearrangement, the proliferation of T lymphocytes was considered to be polyclonal. The T lymphocytes also expressed Fas ligand, suggesting the involvement of Fas-mediated cytotoxicity. This case may represent a new category of cytophagic histiocytic panniculitis induced by exertional rhabdomyolysis.

Adolescent↗
PubMed2002

Ventilatory efficiency and rate of perceived exertion in obese and non-obese children performing standardized exercise.

Sixty children, in the age span 6-17 years originally divided into two groups, matched by age, sex and height--30 obese subjects [15 girls/15 boys; body mass index (BMI) = 27.4 +/- 4.5 m kg-2; ideal body weight (IBW) range = 122-185%] and 30 controls (BMI = 18.8 +/- 2.7 m kg-2) performed incremental treadmill exercise test. Perceived exertion was assessed by means of Category-Ratio Borg scale. The duration of the exercise for the children in the obesity group was significantly shorter than controls (P = 0.010) but obese children have greater absolute values for oxygen uptake (VO2peak ml min-1 = 1907 +/- 671 versus 1495 +/- 562; P = 0.013) and ventilatory variables (VE, VT), which adjusted for body mass decrease significantly (VO2/kg ml min-1 kg-1 = 29.2 +/- 3.8 versus 33.6 +/- 3.5; P < 0.001). Among the various methods for 'normalizing' absolute values of VO2peak for body size, dividing it by body surface area (BSA) yielded the best results (VO2/BSA ml min-1 m-2 = 43.5 +/- 4.6 versus 44.7 +/- 5.6; P = 0.335). The ventilatory efficiency determined either as a slope of VE versus VCO2 or as a simple ratio at anaerobic threshold did not differ between obese and non-obese children in the incremental and recovery periods of exercise. There was a negative correlation of VE/VCO2 slope with age and anthropometric parameters. Obese children rated perceived exertion significantly higher than controls despite the standard workload (Borg score = 6.2 +/- 1.2 versus 5.2 +/- 1.1; P = 0.001). In conclusion, the absolute metabolic cost of exercise is higher in the obesity group compared with the control subjects. Both groups have similar ventilatory efficiency but an increased awareness of fatigue that furthermore limits their physical capacity.

Adolescent↗
PubMed2004

Effect of work duration on physiological and rating scale of perceived exertion responses during self-paced interval training.

This study compared running velocity, physiological responses, and perceived exertion during self-paced interval training bouts differing only in work bout duration. Twelve well-trained runners (nine males, three females, 28+/-5 years, VO2 max 65+/-6 mL min(-1) kg(-1)) performed preliminary testing followed by four "high-intensity" interval sessions (Latin squares, 1 session week(-1) over 4 weeks) consisting of 24 x 1, 12 x 2, 6 x 4, or 4 x 6-min running bouts with a 1:1 work-to-rest interval (total session duration 48 min). The average running velocity decreased (93%, 88%, 86%, 84% vVO2 max, P < 0.01) with increasing work duration. Peak VO2 averaged about 92+/-4% of VO2 max for 2-, 4-, and 6-min intervals compared with only 82+/-5% for 1-min bouts (P < 0.001). Six of 12 athletes achieved their highest average VO2 and heart rate during 4-min intervals. The average RPEpeak (rating scale of perceived exertion) was approximately 17+/-1 for all four interval sessions. RPE increased by 2-4 U during an interval training session. The mean lactate concentration was similar across sessions (4.3+/-1.1-4.6+/-1.5 mmol L(-1)). Under self-paced conditions, well-trained runners perform "high-intensity" intervals at an RPE of approximately 17, independent of interval duration. The optimal interval duration for eliciting a high physiological load is 3-5 min under these training conditions. Increases in RPE during an interval bout are not associated with increasing blood lactate concentration.

Adult↗
PubMed2001

Perceived exertion during incremental cycling is not influenced by the Type A behavior pattern.

Recent publications have perpetuated a concern that the Type A Behavior Pattern (TABP) influences ratings of perceived exertion (RPE) during exercise testing. Previous studies of this topic used the Jenkins Activity Survey (JAS) which lacks validity for predicting the criterion Structured Interview (SI) for TABP and used exercise protocols that were unstandardized or yielded results that were uninterpretable for clinical exercise prescription. We used the SI to classify 44 normotensive men (18-35 y) according to TABP and compared their RPE during an incremental cycling test to peak oxygen uptake (VO2peak). Groups did not differ on maximal test performance or RPE at any stage of the test, even after adjusting RPE for small group variations in % VO2peak and ventilatory equivalent for oxygen, which are strong correlates of RPE during incremental exercise. The findings agree with our prior report [14] that no relationship existed between RPE and several self-report measures of TABP. We conclude that there is no empirical basis for the view that the Type A Behavior Pattern affects cycling performance or ratings of perceived exertion during standard exercise testing in young white men.

Adolescent↗
PubMed2003

Reliability of rating scales of perceived exertion and heart rate during progressive and maximal constant load exercises till exhaustion in physical education students.

The purpose of this study was to assess the reliability of ratings of perceived exertion (RPE) and estimation of time limit (ETL) scales, and heart rate in physical education students during standardised and replicated progressive and constant load exercises till exhaustion realised on a track. Three groups of ten physical education students who present the same anthropometrical characteristics performed an incremental exercise to determine their maximal aerobic velocity (MAV) on an indoor track. Thereafter, group 1 performed an identical incremental exercise whereas groups 2 and 3 performed two identical exercises to exhaustion: a constant load exercise up to exhaustion at 90 and 100 % MAV, respectively, to determine the time to exhaustion at each intensity (tlim 90 and tlim 100). The results of this study were that MAV, tlim 90 and tlim 100 were not significantly different between the two trials. Moreover, the individual Pearson correlation coefficients between test and retests were very high (0.94 to 1). The slope and y intercept values of the relationships between test and retest perceived exertion ratings were not significantly different from the identity line. Moreover, test-retest differences in HR values fell within the 95 % LoA analysis. Consequently, HR values, RPE and ETL scales are reliable during standardised and replicated progressive and constant load exercises till exhaustion performed on a track with physical education students.

Adult↗
PubMed1991

Ratings of perceived exertion among standard treadmill protocols and steady state running.

The purpose of this study was to determine if differences exist in ratings of perceived exertion (RPE) at a predetermined relative heart rate between two standard treadmill protocols and steady state exercise in a field setting. Thirty healthy male (N = 15) and female (N = 15) volunteers were maximally tested using the standard Bruce and a modified Balke (3.0 mph with 2.5% grade each two minutes) protocols. Each subject was randomly assigned to one treadmill protocol first, and then completed the second test forty-eight hours later. Within forty-eight hours following the second treadmill test, all subjects completed a field exercise trial consisting of an 800-m run. During the field trial an investigator paced each subject to an individualized target heart rate (75% maximal heart rate reserve) calculated from the treadmill tests. The total exercise time for the field trial was 4:31 +/- 0:22 and 5:36 +/- 0:47 min for the males and females, respectively. During the last 50 m of the field trial, RPE values were recorded. Comparisons of the rating of perceived exertion at the target heart rate (RPE at THR) were made using a 2-way (Gender x Trials) ANOVA with repeated measures across trials. There was a significant gender x trials interaction for RPE at THR, with males reporting significantly higher values during the treadmill tests as compared to the females (BRUCE = 13.5 +/- 1.6 vs 12.2 +/- 1.8; BLAKE = 15.9 +/- 2.3 vs 13.7 +/- 2.4). There was no difference noted between genders for RPE at THR during the field trial.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗