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At least 793 records · Page 44Linked to original sources
PubMed1988

Incidence of exertional right ventricular wall motion abnormalities in patients with coronary artery disease.

To evaluate the role of analysis of right ventricular function with exercise in patients with presumed coronary artery disease referred for radionuclide ventriculography, the records of 55 patients referred to our laboratory over a 19-month period were reviewed. All underwent rest and exercise first-pass radionuclide stress testing and cardiac catheterization within a period of four months. Three groups were identified: (1) patients with normal exercise right ventricular function (n = 24); (2) patients with exercise-induced right ventricular regional wall motion abnormalities (n = 15); and, (3) patients with abnormal resting right ventricular function without new exercise abnormalities (n = 16). Patients in each group were similar in age, sex, baseline left ventricular function, medication usage, and indication for study. The incidence of right coronary artery disease was identical in the three groups, as was the incidence of left ventricular functional abnormalities with exercise. Patients with proximal right coronary artery disease were more likely to have reduced left ventricular ejection fraction and more extensive coronary artery disease than those without disease at this site. We conclude that: (1) analysis of rest and exercise right ventricular function does not allow prediction of coronary anatomy in an unselected group of patients; (2) normal right ventricular function with exercise is compatible with extensive coronary artery disease, including proximal right coronary artery disease; and (3) abnormal exercise right ventricular function may be due to exertional left ventricular dysfunction in the absence of proximal right coronary artery disease.

Cardiac Catheterization↗
PubMed1991

A case of cardiac amyloidosis presenting with symptoms of exertional syncope.

A 54-year-old man presented with symptoms of exertional syncope. Cardiac amyloidosis was diagnosed by endomyocardial biopsy. Exercise tolerance test revealed a failure of increased heart rate followed by sinus arrest, associated with syncope. Autopsy revealed amyloid deposits in the sinoatrial node.

Amyloidosis↗
PubMed1987

Lumbar trunk muscle use in standing isometric heavy exertions.

A study was conducted to see whether a biomechanical model previously validated for predicting the lumbar spine internal loads imposed by the performance of easy and moderately strenuous physical tasks was also adequate for predicting loads imposed by heavy exertions. Lumbar trunk muscle myoelectric activities were measured in 10 healthy young adult men performing a variety of less strenuous and more strenuous tasks while standing upright, and these were compared to the lumbar muscle contraction magnitudes predicted by the model. For the less strenuous tasks, measured activities and predicted forces showed strong linear correlations, confirming the validity of the model at those load levels. Model predictions for the more strenuous tasks were often found to be inadequate. Contrary to model-incorporated assumptions, substantial antagonistic muscle contractions sometimes occurred, intraabdominal pressurization may sometimes have contributed substantially to the maintenance of structural equilibrium, and the ligamentous tissues of the trunk seemed sometimes to develop substantial passive resistances to bending and twisting moments.

Adult↗
PubMed1991

Validity of heart rate and ratings of perceived exertion as indices of exercise intensity in a group of children while swimming.

The purpose of this study was to investigate the validity of heart rate (fc) and ratings of perceived exertion (RPE) as indices of exercise intensity in a group of children while swimming. Six healthy male swimmers, aged 10-12, swam tethered using the breast-stroke in a flume. The resistance started at 1.0 kg and increased in 1.0 kg steps up to the point of their exhaustion. The subjects swam for 5 min during each period, with a rest of 10-20 min until they had returned to their resting fc level. The last exercise intensity was with the maximal mass the subjects could support for 2 min. The last min of oxygen consumption (VO2) and 30 s of fc were measured during each exercise period. The subjects gave their RPE assessment at the end of exercise. The individual relationships between fc and VO2, and percentage maximal oxygen consumption (%VO2max) were linear with a high correlation r = 0.962-0.996 and r = 0.962-0.996, respectively. Therefore, it was concluded that fc was valid as an index of the exercise intensity of children while swimming. Compared to the results found in adults using a similar protocol, the children's fc were 8.3-26.9 beats.min-1 higher than those of the adults at the given %VO2max. The present study showed two different patterns in the relationship between VO2 and RPE in individuals. In two subjects the RPE increased linearly with VO2 while in the other four subjects the increase was discontinuous. If fc and RPE were to be applied to the setting and evaluation of exercise intensity during swimming, it would seem that fc would be a more useful guide than RPE for some children.

Body Height↗
PubMed1989

Surface EMG amplitude and frequency dependence on exerted force for the upper trapezius muscle: a comparison between right and left sides.

Surface electromyographic (EMG) amplitude and mean power frequency (MPF) were used to study the isometric muscular activity of the right versus the left upper trapezius muscles in 14 healthy right-handed women. The EMG activity was recorded simultaneously with force signals during a 10-15 s gradually increasing exertion of force, up to maximal force. Only one side at a time was tested. On both sides there was a significant increase in EMG amplitude (microV) during the gradually increasing force from 0% to 100% maximal voluntary contraction (MVC). The right trapezius muscle showed significantly less steep slopes for regression of EMG amplitude versus force at low force levels (0%-40% MVC) compared intra-individually with high force levels (60%-100% MVC). This was not found for the left trapezius muscle. At 40% MVC a significantly lower MPF value was found for the right trapezius muscle intra-individually compared with the left. An increase in MPF between 5% and 40% MVC was statistically significant when both sides were included in the test. The differences in EMG activity between the two sides at low force levels could be due to more slow-twitch (type I fibres) motor unit activity in the right trapezius muscles. It is suggested that this is related to right-handed activity.

Adult↗
PubMed1979

Effect of air ionization on heart rate and perceived exertion during a bicycle exercise test. A double-blind cross-over study.

The influence of ionization of air on heart rate (HR) and ratings of perceived exertion (RPE) during bicycle exercise was studied in nine healthy medical students selected according to a randomized schedule from the class of 90 students. The exercise tests were performed both under negative and positive ionization. The study was made with a double-blind, cross-over design. The body surface exposed to ionic current was made large by reducing the clothing of the subject. A significant overall tendency to lower HR and RPE values under negative ionization was observed (p less than 0.01, sign tests). The RPE values were significantly lower (p less than 0.01, paired t-test and the Wilcoxon test) under negative than under positive ionization at the maximal work load level but not at other relative load levels. However, when separately tested at each relative load level HR values did not differ significantly in negative and positive ionization. The results of this pilot study indicate that ionic composition of the air can modify the RPE and possibly also HR during exercise; negative air ionization seems to be beneficial compared with positive ionization. The mechanisms involved are obscure, but we suggest that negative ionization of air may increase oxidative metabolism through generation of a superoxide radical (O2-) that is reduced to H2O2 by superoxide dismutases.

Adult↗
PubMed1978

Recurrent exertional rhabdomyolysis and stunted growth.

A boy with recurrent exertional rhabdomyolysis and stunted growth is described. Fetal movements were few and the boy was small for gestational age. He always experienced easy fatigability, and he noted bouts of pigmenturia associated with episodes of considerable malaise. The change in color of the urine was caused by myoglobin. An electromyogram was myopathic. CPK rose during 60 minutes mild exercise. Prolonged moderate exercise could not be performed. Histopathological examination of muscle biopsy revealed an increase in the number of 11C fibres (20%). Electronmicroscopy revealed the wavy outline of a number of fibres and hypertrophy of sarcoplasmic reticulum elements. No cause for the stunted growth could be detected.

Biopsy↗
PubMed1991

Ratings of perceived exertion in chronic obstructive pulmonary disease--a possible indicator for exercise training in patients with this disease.

The purpose of this study was to evaluate the usefulness of ratings of perceived exertion (RPE) as an indicator of exercise intensity in patients with chronic obstructive pulmonary disease (COPD). The subjects were ten male patients with COPD, whose mean forced expiratory volume in 1 s was 1.09 1, SD 0.41, and ten healthy middle-aged men. Ramp incremental exercise on a cycle-ergometer was performed and RPE was determined by the Borg 15-point scale. The absolute oxygen uptake at each RPE was significantly greater in the healthy subjects than in the patients with COPD. However, oxygen uptake calculated as a percentage of maximal at any RPE did not differ significantly between the two groups. Arterial blood lactate concentration at points 15 to 19 on the RPE scale was increased in healthy subjects (P less than 0.05-P less than 0.001), while the dyspnoea index at points 11 to 19 on the RPE scale was higher in patients with COPD (P less than 0.05-P less than 0.001). The main complaints on stopping exercise were dyspnoea in the patients with COPD and fatigue in the healthy subjects. Although the nature of RPE may have been different in the two groups, RPE could be a possible indicator of exercise intensity when physicians prescribe exercise to patients with COPD.

Adult↗
PubMed1987

Effect of training on the rating of perceived exertion at the ventilatory threshold.

The purpose of this study was to determine the effect of training on the rating of perceived exertion (RPE) at the ventilatory threshold. College students were assigned to either training (n = 17) or control (n = 10) groups. Trainers completed 18 interval training sessions (five X 5 min cycling at 90-100% VO2max) and 8 continuous training sessions (40 min running or cycling) in 6 weeks. Pre- and post-training, cardiorespiratory, metabolic, and perceptual variables were measured at the ventilatory threshold during graded exercise tests on a cycle ergometer. Ventilatory threshold was that point above which VE X VO2-1 increased abruptly relative to work rate. Post-training means of trained and control subjects were compared using analysis of covariance, with pre-training values as covariates. Following training, the adjusted means for the trained subjects were significantly greater (p less than 0.05) than for controls for VO2max (6%), and for work rate (20%), VO2 (23%), and %VO2max (13%) at the ventilatory threshold. However, adjusted means for RPE at the ventilatory threshold were not significantly different (2%). Both before and after training, exercise at the ventilatory threshold was perceived as 'somewhat hard' to 'hard' (RPE = 13-15) by both groups. The relationship between RPE and %VO2max was altered by training, with trained subjects having a lower RPE at a given %VO2max. It is concluded that RPE at the ventilatory threshold is not affected by training, despite that after training the ventilatory threshold occurs at a higher work rate and is associated with higher absolute and relative metabolic and cardiorespiratory demands.

Adult↗
PubMed1990

Myopathic evolution of an exertional muscle pain syndrome with phosphorylase b kinase deficiency.

The symptoms of a myopathy permanently affecting limb girdle muscles are reported in a 31-year-old woman who has been presenting an exertional muscle pain syndrome with myoglobinuria for 20 years. Investigations revealed a slightly decreased utilization of glycogen in muscle, while its storage affected only rare type 2 fibers. Active phosphorylase was undetectable and phosphorylase b kinase activity was clearly decreased in muscle cells, but normal in erythocytes, lymphocytes and cultured fibroblasts.

Adult↗
PubMed1975

Methodical aspects of perceived exertion rating and its relation to pedalling rate and rotating mass.

Methodical aspects of the relationship between pedalling rate and rotating mass and perceived exertion rating (PER; Borg, 1962) were studied in trained, untrained, and ill subjects in bicycle ergometry. Pedalling rate varied between 40 and 100 rpm, work load steps were 5, 10, 15 and 20 mkp/sec in the healthy subjects, and 2.5, 5, 7.5 and 10 mkp/sec in the patients. PER decreased with increasing pedalling rate in all healthy subjects. In the patients, PER increased moderately at work load of 2.5 mkp/sec, but decreased at higher work loads up to 80 rpm, followed by a slight increase at 100 rpm. Higher mass of the flywheel, studied in 6 trained subjects, lowered the PER insignificantly. In the healthy subjects, test criteria, such as reproducibility, reliability, sensitivity, and linearity remained almost unaffected by pedalling rate. In patients, increasing pedalling speed diminished reproducibility and sensitivity. The strictness of the PER work load relationship is lowered at higher pedalling rate, especially at 100 rpm. When using the PER scale, pedalling rate has to be considered as an factor of main influence.

Adult↗
PubMed1989

Ratings of perceived exertion in individuals with varying fitness levels during walking and running.

It was the purpose of this investigation to: 1) compare the ratings of perceived exertion (RPEs) in high and low fit individuals when walking and running at comparable exercise intensities and 2) to determine if ventilation (VE) provides a central signal for RPEs. Nine high fit and nine low fit male subjects completed two exercise bouts on a treadmill, one uphill walking and the other level running. Workloads for each bout were set at 90% of each subject's ventilatory threshold (VT) as determined from a graded exercise test. Oxygen consumption (Vo2), heart rate (HR), and VE were all similar between the walk and run trials for the low fit subjects (P greater than 0.05). HR were found to be significantly greater during the walk trial vs. the run trial (P less than 0.05) for the high fit subjects, whereas, VE was significantly greater during the run trial. Oxygen consumption was similar for the high fit subjects during both trials (P greater than 0.05). During the walk and run trials, central (12.1 +/- 1.6 vs. 11.4 +/- 1.5), local (14.0 +/- 1.3 vs. 13.9 +/- 1.1) and overall (12.8 +/- 1.2 vs. 12.4 +/- 1.4) RPEs were not found to be significantly different for the low fit group (P greater than 0.05). In contrast, during the walk vs. the run trial there was a significant increase in central (10.7 +/- 2.0 vs. 9.2 +/- 1.9), local (11.5 +/- 2.0 vs. 9.8 +/- 1.8) and overall (11.2 +/- 2.4 vs. 9.6 +/- 2.3) RPEs for the high fit group (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

The effects of specificity of training on rating of perceived exertion at the lactate threshold.

To determine the effects of cycle and run training on rating of perceived exertion at the lactate threshold (LT), college men completed a 40-session training program in 10 weeks (n = 6 run training, n = 5 cycle training, n = 5 controls). Pre- and post-training variables were measured during graded exercise tests on both the bicycle ergometer and treadmill. ANOVA on the pre- and post-training difference scores resulted in similar improvements in VO2max for both testing protocols, regardless of training mode. The run training group increased VO2 at the LT by 58.5% on the treadmill protocol and by 20.3% on the cycle ergometer. Cycle trainers increased VO2 LT only during cycle ergometry (+38.7%). No changes were observed in the control group. No differences for RPE at the LT were found before or after training, or between testing protocols for any group. Perception of exercise intensity at the LT ranged from "very light" to "light". The relationship between RPE and %VO2max was altered by the specific mode of training, with trained subjects having a lower RPE at a given %VO2max (no change in RPE at max.). It was concluded that RPE at the LT was not affected by training, despite the fact that after training the LT occurs at a higher work rate and was associated with higher absolute and relative metabolic and cardiorespiratory demands.

Adolescent↗
PubMed1990

Technetium-99m MDP scintigraphy of rhabdomyolysis induced by exertional heat stroke: a case report.

A case of rhabdomyolysis induced by exertional heat stroke in a police officer recruit is reported. Technetium-99m methylene diphosphonate scintigraphy demonstrated marked uptake of the injured skeletal muscle. This bone-scanning agent provided an excellent means of localizing and evaluating the muscle injury of rhabdomyolysis. Nuclear medicine physicians should be aware of the special conditions and causes in which bone scan may demonstrate striking findings.

Adult↗
PubMed1997

Chronic exertional dyspnea and respiratory muscle function in patients with chronic obstructive pulmonary disease.

The symptom of breathlessness is an important outcome measure in the management of patients with chronic obstructive pulmonary disease (COPD). Clinical ratings of dyspnea and routine lung function are weakly related to each other. However, in the clinical setting breathlessness in COPD is encountered under conditions of increased respiratory effort, impeded respiratory muscle action, or functional weakness. Thus, the present study was carried out to determine whether and to what extent clinical ratings of dyspnea and respiratory muscle dysfunction relate to each other. In 21 patients with COPD two methods were used to rate dyspnea: a modified Medical Research Council Scale (MRC) and the Baseline Dyspnea Index (BDI), which is a multidimensional instrument for measuring dyspnea based on three components: magnitude of task, magnitude of effort, and functional impairment. A baseline focal score was obtained as the sum of the three components. Measures were: pulmonary volumes; arterial blood gases; maximal voluntary ventilation (MVV); maximal inspiratory and expiratory pressures (MIP and MEP, respectively); and breathing patterns ventilation (VE), tidal volume (VT), and respiratory frequency (Rf). In 15 patients pleural pressure was also measured during both quiet breathing (Pplsw) and maximal inspiratory sniff maneuver at FRC (Pplsn). BDI and MRC ratings related to each other and showed comparable weak associations with standard parameters (FEV1, PaCO2, VT), MIP, and MEP. In contrast, MVV closely and similarly related to both ratings. Pplsw (%Pplsn), a measure of respiratory effort, and Pplsw (%Pplsn)/VT(%VC), an index of neuroventilatory dissociation, related significantly to both the BDI (r2 = -0.77 and r2 = -0.75, respectively) and the MRC (r2 = 0.81 and r2 = 0.74, respectively). Using MVV, Pplsw (%Pplsn), and Pplsw (%Pplsn)/VT(%VC) in a stepwise multiple regression as independent variables with BDI rating as dependent variable, MVV explained an additional 14.5% of the variance of the BDI over the 67.8% predicted by Pplsw (%Pplsn). Our results demonstrate that the level of chronic exertional dyspnea in COPD increases as the ventilatory muscle derangement increases. The level of the relationships among dyspnea ratings and MVV and respiratory effort helps to explain some of the mechanisms of chronic dyspnea of COPD. These measures should be considered for therapeutic intervention to reduce dyspnea.

Dyspnea↗
PubMed2005

Two minimal incision fasciotomy for chronic exertional compartment syndrome of the lower leg.

Chronic exertional compartment syndrome (CECS) of the leg is a pathological condition often related to overuse in subject who engage repetitive physical activities. Fascial release is the mainstay of surgical management. The purpose of this study was to evaluate the results obtained with a double incision decompressive fasciotomy. Eighteen consecutive athletes with a diagnosis of anterior and/or lateral CECS of the leg were operated on with a minimal double incision fascial release after a mean period of 4 months after onset of symptoms. In 11 cases (61%) CECS was bilateral. Surgery was performed without tourniquet and active mobilization was starting immediately. Sports activities were resumed gradually at a mean period of 25 days. The athletes were followed until 2 years. All resumed pre-injury level sports activity. Two patients (18%) of the 11 who underwent to bilateral fasciotomy referred a sensation of leg weakness for an average period of 3 months. The surgical technique presented in this paper seems to be a good mean to treat anterior and lateral leg CECS. The use of tourniquet is deconselled to obtain an accurate intraoperative haemostasis so reducing the risk of post-operative haematoma.

Adult↗
PubMed2002

Reproducibility of the blood lactate threshold, 4 mmol.l(-1) marker, heart rate and ratings of perceived exertion during incremental treadmill exercise in humans.

The aim of this study was to investigate the reproducibility of blood lactate measurements, heart rate (HR) and ratings of perceived exertion (RPE) during treadmill exercise at speeds corresponding to the lactate threshold ( v(Th,la)-) and a fixed blood lactate concentration of 4 mmol.l(-1)( v(la)-(,4)). Possible differences in reproducibility related to fitness levels were also investigated. A group of 20 men [mean (SD)] [age 20.5 (1.4) years] and 16 women [age 21.2 (0.9) years] took part in the study. The subjects performed two identical incremental exercise tests consisting of at least six 4 min stages. Blood lactate concentrations, HR and RPE were recorded at the end of each stage. Limits of agreement (LoA), correlation coefficients and 95% confidence intervals for the mean difference between tests were employed to investigate the level of agreement and reproducibility of blood lactate concentration, HR and RPE. For the group as a whole, the sample correlation coefficient for speed at v(Th,la)- was r=0.88, and was r=0.92 for the speed at v(la)-(,4). At v(Th,la) -, the correlation coefficients for the moderately fit and unfit were r=0.94 and r=0.36, respectively, and at v(la)-(,4) r=0.93 and r=0.68, respectively. The LoA for the moderately fit group indicated that a change of 1.62 km.h(-1) in v(Th,la)- would be necessary to be considered a change in training status. For HR and RPE, relationships between the tests were generally poor. The LoA suggested that changes in scores must be unacceptably large. These findings cast doubt on the sensitivity of testing for change of blood lactate concentration, HR and RPE in this population.

Adult↗