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PubMedDate not supplied

Exertion and body discomfort perceived symptoms associated with carpentry tasks: an on-site evaluation.

The purpose of this study was to determine how carpenters subjectively perceived the exertion level and body discomfort associated with their daily tasks. Two psychophysical instruments were utilized. The Borg Whole Body Physical Exertion Instrument, a measure of overall physical demand, and the Body Segment instrument (modified Bishop-Corlett Scale), a measure of body discomfort, were given to 73 carpenters at the end of a shift. Carpentry specialties evaluated included ceiling, drywall, formwork, finishing work, pile driving, fixtures, welding, and scaffolding. The mean Borg's exertion score for the subjects combining all specialties was 14.4 (+/-2.51 standard deviation), a score between "somewhat hard" and "hard." The perception of whole body physical exertion appeared to be a consequence of the specific task. There was no significant correlation between whole body physical exertion perception and age or the number of years as a carpenter. The findings from the body discomfort scale for the total group indicated that the three primary discomfort frequencies by body segment were mid-to-lower back (65.8%), knees (45.2%), and the neck (28.8%). The next highest discomfort rating by body segment (back, knee, right wrist, right leg/foot, and right shoulder) for those subjects in the top three job specialties represented (drywall, ceiling, and formwork; n = 38) resulted in significantly higher ratings for back (60.5%) than right leg/foot (34.2%) and right shoulder (31.6%). All other body segment ratings were not significantly different from one another using Tukey's studentized range test.

Adult↗
PubMed1983

Perceived exertion of physical effort for various manual handling tasks.

Ten trained male students between 18 and 28 years of age participated in a study, designed to determine the relationship between perceived exertion and physiological costs of exertion during various manual lifting and lowering tasks. Perceived exertion was defined as one's subjective rating of the intensity of work being performed. Five subjects performed lifting tasks and another five performed lowering tasks. Weight of load lifted or lowered (6.8, 13.6, 20.5 kg), frequency of lift or lower (3, 6, 9 times/min), height of lift or lower (floor to 76 cm, 76 to 127 cm, floor to 127 cm), box width (38, 66 cm), box length (38, 66 cm) and angle of twist of the body (0 degree, 90 degrees) were the independent variables studied. Heart rate, oxygen consumption, and ratings of perceived exertion (RPE) were the response measures. RPE was found almost linearly related to heart rate and oxygen consumption when lifting or lowering loads. For lifting tasks, the coefficient of correlation between RPE and heart rate was 0.673. In the case of lowering tasks, this coefficient was 0.604. When oxygen consumption was considered, the corresponding coefficients for lifting and lowering were 0.734 and 0.619, respectively. The correlation of RPE with the physiological response variables indicates that the severity of manual materials handling tasks in industry can be evaluated quickly and inexpensively by using perceived exertion ratings (RPE).

Adolescent↗
PubMed1997

Energy metabolism in exertional heat stroke with acute renal failure.

BACKGROUND: Heat stroke is the clinical syndrome produced when the body overheats. It can develop in the army and in healthy civilian populations who physically exert themselves in a hot and humid environment during the summer, and may result in a significant number of heat-related deaths. Since strenuous exercise is one of the major exacerbating and precipitating factors, the incidence of exertional heat stroke (ExHS) is high among military personnel undergoing military training. Furthermore, acute renal failure (ARF) may occur in 25% of patients with ExHS and it can cause metabolic alterations that affect amino acid, carbohydrate, and lipid metabolism. Adequate nutritional support is essential for the treatment of ARF. The most important determinant of nutrient requirement in ARF is the degree of hypercatabolism caused by disease associated with renal function impairment. Indirect calorimetry (IDCM) is the method by which metabolic rate is estimated from measurements of oxygen consumption and carbon dioxide production. It can also provide information about the type and rate of substrate utilization in vivo (protein, carbohydrate, and fat). METHOD: The present clinical study is a comprehensive analysis of metabolic changes which includes energy expenditure (EE) and substrate utilization in 10 patients with ExHS with ARF and 10 patients with exertional heat exhaustion (ExHE) by the use of IDCM. RESULTS: Serum urea nitrogen, creatinine, peak creatine phosphokinase levels and heart rate were significantly increased in ExHS patients during ARF stage. Serum albumin levels were significantly decreased in ExHS patients with ARF. Resting energy expenditure (REE) was increased in patients with ExHS induced ARF and was not correlated with body temperature (r = 0.421). The average increase in EE during ARF stage was about 24%. The respiratory quotient in patients with ExHS induced ARF was lower than that in normal subjects and also in patients with ExHE. Urea nitrogen appearance rate increased in patients with ExHS induced ARF and in patients with ExHE without ARF. The percentage of total REE derived from fat in ExHS induced ARF and ExHE increased, while in patients with ExHS induced ARF and ExHE, the percentages of total REE derived from carbohydrate and protein were lower than those in control subjects. CONCLUSIONS: The present results suggest that patients with exertional heat injury (both ExHS and ExHE) have hypermetabolism during the acute stage. Furthermore, patients with exertional heat-induced rhabdomyolysis and ARF have a moderately higher hypermetabolism than those without ARF during the acute stage. We believe that this mainly reflects a more pronounced reduction of the vital cell mass (muscle) in relation to body weight, and/or a compromised substrate oxidation in ExHS with ARF. Whether or not this subgroup of patients will require a higher energy/caloric support merits further investigation.

Acute Kidney Injury↗
PubMedDate not supplied

Six-minute walk by people with chronic renal failure. Assessment of effort by perceived exertion.

The ability to exercise among 20 people with chronic renal failure was assessed on three tests by measuring the distance walked in 6 min, heart rate change from pre-exercise to postexercise and perceived exertion. Test 1 was conducted to minimize practice effects. Ten participants received exercise coaching for 3 mo between Tests 2 and 3, and 10 individuals were in a control group. Distance walked was highly correlated on the three tests; heart rate change and perceived exertion were only slightly less consistent. Three people changed their perceived exertion by more than one point between Tests 2 and 3, and these changes obscured differences between the exercise and control groups. Exclusion of data for those who changed by more than one point equalized perceived exertion changes in the two groups and revealed a significant (P < 0.05) increase in distance in the exercise group (+21.8 m) but not in the control group (+1.5 m). The study demonstrates that, although perceived exertion ratings are intended for use in incremental exercise testing, they are also valuable for assessing consistency v change in the effort of individual participants in single-intensity testing, such as a self-paced walk.

Adult↗
PubMed2002

Fatigue-related changes in torque output and electromyographic parameters of trunk muscles during isometric axial rotation exertion: an investigation in patients with back pain and in healthy subjects.

STUDY DESIGN: A cross-sectional case-control study. OBJECTIVES: To examine the effect of fatigue on torque output as well as electromyographic frequency and amplitude values of trunk muscles during isometric axial rotation exertion in back pain patients and to compare the results with a matched control group. SUMMARY OF BACKGROUND DATA: Back pain patients exhibited different activation strategies in trunk muscles during the axial rotation exertions. Fatigue changes of abdominal and back muscles during axial rotation exertion have not been examined in patients with back pain. METHODS: Twelve back pain patients and 12 matched controls performed isometric fatiguing axial rotation to both sides at 80% maximum voluntary contraction in a standing position. During the fatiguing exertion, electromyographic changes of rectus abdominis, external oblique, internal oblique, latissimus dorsi, iliocostalis lumborum, and multifidus were recorded bilaterally. The primary torque in the transverse plane and the coupling torques in sagittal and coronal planes were also measured. RESULTS: No difference in the endurance capacity was found between back pain and control groups. At the initial period of the exertion, back pain patients demonstrated a statistical trend (P = 0.058) of greater sagittal coupling torque as well as lower activity of rectus abdominis and multifidus and higher activity in external oblique. During the fatigue process similar changes of coupling torque were demonstrated in both sagittal and coronal planes, but a smaller fatigue rate for right external oblique, increase in median frequency for latissimus dorsi, and lesser increase in activity for back muscles were found in the back pain group compared with the control group. CONCLUSIONS: Alterations in electromyographic activation and fatigue rates of abdominal and back muscles demonstrated during the fatigue process provide insights into the muscle dysfunctions in back pain and may help clinicians to devise more rational treatment strategies.

Abdomen↗
PubMed1983

Heart rates in fire fighters using light and heavy breathing equipment: similar near-maximal exertion in response to multiple work load conditions.

Intense exertion is an occupational hazard inherent to fire fighting. This study was designed to look at the exertion levels that fire fighters attain during a fire fighting exercise when using (1) no self-contained breathing apparatus (SCBA), (2) light SCBA, and (3) heavy SCBA. Exertion levels were measured as a function of the heart rate increase relative to the maximum predicted heart rate determined by a standard treadmill exercise test. Five fire fighters wore electrocardiographic monitors during a routine fire fighting exercise. Heart rates increased rapidly to 70% to 80% of maximum within the first minute and then plateaued at 90% to 100% until the attack on the fire was completed. There was no significant difference between exertion levels when using no SCBA, light SCBA, and heavy SCBA (split-plot analysis of variance, p greater than .25). These results suggest that fire fighters attain an intense level of physical activity quickly and maintain that level as long as they are actively engaged in fighting fire. These results also suggest that regardless of the weight of the SCBA, if employed, fire fighters exert themselves from 85% to 100% of their maximum and adjust their work output to maintain that near-maximal level.

Adult↗
PubMed1987

Exertional gastro-oesophageal reflux: a mechanism for symptoms in patients with angina pectoris and normal coronary angiograms.

During 24 hour oesophageal pH monitoring 52 patients who had angina pectoris and normal coronary angiograms underwent exercise testing, as far as their symptoms allowed, on a treadmill to determine whether gastro-oesophageal reflux occurred during exertion. In 11 patients the 24 hour oesophageal pH score was abnormally high; 10 of these showed exertional gastro-oesophageal reflux, and in nine this was associated with their usual chest pain. A further 13 patients had a normal 24 hour pH score but had exertional reflux coincident with chest pain during exercise testing. The mean lower oesophageal sphincter pressure in both of these groups of patients was appreciably lower than that in 28 patients who had a normal 24 hour pH score and no exertional reflux. These findings suggest that exertional gastro-oesophageal reflux accounts for the symptoms of a large proportion of patients who have angina pectoris and normal coronary angiograms and that oesophageal pH monitoring during exercise testing on a treadmill enables this group of patients to be identified.

Adult↗
PubMed1991

Benign vascular sexual headache and exertional headache: interrelationships and long term prognosis.

There is a definite relationship between the vascular type of benign sexual headache and benign exertional headache. Forty five patients with benign vascular sexual headache were reviewed. Twenty seven (60%) experienced benign vascular sexual headache alone and eighteen (40%) had experienced both benign vascular sexual headache and benign exertional headache on at least one occasion. The mean age was 34.3 years with a male:female ratio of 5.4:1. Thirty patients with a history of benign vascular sexual headache were followed for an average of 74 months. A personal history of migraine was found in 47% of cases and a family history of migraine in 30%. Forty one per cent of patients with benign vascular sexual headache alone had recurrences after diagnosis, and stress and fatigue were considered major contributing factors to the initial and recurrent headache. Nine patients had experienced benign vascular sexual headache and benign exertional headache within 72 hours of each other on at least one occasion, often with a residual headache between the two. Four patients experienced their benign vascular sexual headache and benign exertional headache separated by months to years. The prognosis of benign vascular sexual headache and the clinical and possible pathophysiological relationships between benign vascular sexual headache and benign exertional headache are discussed. Knowledge of the interrelationships of these varieties of headache is valuable in the counselling of patients.

Adult↗
PubMed1976

Exertional hypotension due to postganglionic sympathetic blocking drugs.

Debrisoquine, guanethidine and bethanidine may produce troublesome hypotensive symtoms related to exertion. Thirteen patients with such symptoms were exercised on a treadmill and the response of blood pressure and heart rate was compared to that of thirty patients without these symptoms, who were exercised to the same extent. There was a slight drop of systolic and diastolic pressures on standing in both groups, but after exertion there was a significantly greater drop of systolic pressure in the group with symptoms than in the asymptomatic group. The diastolic pressure after exertion was significantly lower in the group with symptoms. It was impossible to predict from the standing blood pressure levels at rest which patients would develop hypotensive symptoms after exertion. All three drugs had a similar negative chronotropic effect at rest and on exercise. It is suggested that patients are exercised during control of hypertension in order to identify those prone to exertional hypotension. Patients with such hypotension should be exercised on each attendance before the blood pressure is measured. Treatment other than postganglionic sympathetic blocking drugs should be employed whenever possible in patients with milder hypertension.

Bethanidine↗
PubMed1986

Vasodilator reserve in respiratory muscles during maximal exertion in ponies.

Eight healthy adult grade ponies were studied at rest as well as during maximal exertion carried out with and without adenosine infusion (3 microM X kg-1 X min-1 into the pulmonary artery) on a treadmill to compare levels of blood flow in respiratory muscles with those in other vigorously working muscles and to ascertain whether there remained any unutilized vasodilator reserve in respiratory muscles of maximally exercising ponies. Radionuclide-labeled 15-micron-diam microspheres, injected into the left ventricle, were used to study tissue blood flows. During maximal exertion, there were increases above base-line values in heart rate (336%), mean aortic pressure (41%), cardiac output (722%), and arterial O2 content (56%). The whole-body O2 consumption was 123 +/- 11 ml X min-1 X kg-1, and the stride/respiratory frequency of the galloping ponies was 138 +/- 4/min. With adenosine infusion during maximal exertion, mean aortic pressure decreased (P less than 0.05), but none of the above variables was different from maximal exercise alone. During maximal exertion, blood flow in the adrenal glands, myocardium, respiratory, and limb muscles increased, whereas that in the kidneys decreased and the cerebral perfusion remained unaltered. With adenosine infusion during maximal exercise, renal vasoconstriction intensified, whereas adrenal and coronary beds exhibited further vasodilatation. During maximal exertion, blood flow in the equine diaphragm (265 +/- 36 ml X min-1 X 100 g-1) was not different from that in the gluteus medius (253 +/- 36) and biceps femoris (233 +/- 29); both are principal muscles of propulsion in the equine subjects) or the triceps brachii (227 +/- 26) muscles.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗
PubMed2003

Triggers of subarachnoid hemorrhage: role of physical exertion, smoking, and alcohol in the Australasian Cooperative Research on Subarachnoid Hemorrhage Study (ACROSS).

BACKGROUND AND PURPOSE: Unaccustomed strenuous physical exertion can trigger myocardial infarction, but little is known about the mechanisms precipitating subarachnoid hemorrhage (SAH). METHODS: We identified all cases of first-ever SAH among the combined populations (2.8 million) of 4 urban centers in Australia and New Zealand. Information on the type, time, and intensity of exposures in the 26 hours before the onset of SAH was ascertained by structured interviews. We used the case-crossover technique to assess the risk of SAH associated with transient exposures of moderate to extreme physical exertion, heavy cigarette smoking, and binge alcohol consumption. RESULTS: We registered 432 first-ever cases of SAH (62% women; mean age, 56.5 years). A definite time of onset of SAH was established for 393 patients (91%), and information on the levels of physical activity in the preceding 26 hours was obtained in 338 (78%). Of these patients, 19% engaged in moderate to extreme exertion (>or=5 metabolic equivalents) in the 2 hours before SAH, which was associated with a tripling in the risk of SAH (odds ratio [OR], 2.7; 95% CI, 1.6 to 4.6). There was no evidence of any association between heavy cigarette smoking or binge drinking and risk of SAH in the subsequent 2 hours (OR, 1.1; 95% CI, 0.4 to 3.7; and OR, 0.41; 95% CI, - infinity to 5.3). Habitual exercise did not appear to alter the risk of SAH associated with moderate to extreme exertion. CONCLUSIONS: Moderate to extreme physical exertion tripled the risk of SAH, but there was no association between transient heavy smoking or binge drinking and risk of SAH. These data suggest that heavy physical activity may trigger SAH.

Adult↗
PubMed2004

Verbal estimation of peak exertion intensity.

The objectives of this research were to investigate the accuracy and precision with which trained and untrained participants estimate the magnitude of forceful exertion and to evaluate the mathematical relationship between actual and estimated exertion. Three groups of participants estimated, as a percentage of maximum voluntary contraction (%MVC), the magnitude of submaximal exertion for 12 simulated tasks. In addition to the control group, one group was exposed to one physical benchmark (100% MVC) and another to three benchmarks (25%, 75%, and 100% MVC) prior to force estimation. Error (estimated minus actual) significantly decreased (p < .0001) from 14% MVC to 4% MVC with one benchmark and to -3% MVC with three benchmarks, as compared with the control group. Furthermore, the standard deviation decreased significantly (p < .0001 ) from the control group (16.6% MVC) to the one-benchmark group (13.8% MVC) to the three-benchmark group (11.6% MVC), indicating improved precision. Significant interaction effects were observed, but their impact on main effects was negligible. Also, linear, power, and logarithmic regression models described the relationship between perceived and actual exertion equally well (R2 = .64-.81). Applications of this research include improving the accuracy and precision of field-based psychophysical estimates of forceful exertion for epidemiological research and other field-based analyses.

Adult↗
PubMed2005

Carbohydrate supplementation and perceived exertion during resistance exercise.

The purpose of the present study was to investigate the relationship between carbohydrate energy substrate and the perception of exertion during resistance exercise. Thirty strength-trained subjects were randomized to a carbohydrate group (C) or a placebo group (P), and lifted weights for 2 hours (4 sets; 10 repetitions maximum; 10 exercises; 2-3-minute rest intervals). Subjects ingested 10 ml.kg(-1).h(-1) of 6% carbohydrate or placebo beverages during the resistance-training bout. The 15-category Borg Perceived Exertion Scale was used to assess overall body (RPE-O) and active muscle (RPE-AM) perceived exertion after completion of the last repetition in each set for each exercise. No significant differences were found between the C and P groups for either RPE-O or RPE-AM, with the exception of RPE-O for the upright row and back squat (p < 0.05). Carbohydrate supplementation exerted no attenuating effect on ratings of perceived exertion (RPE) during resistance training.

Adult↗
PubMed2006

Perceived exertion : influence of age and cognitive development.

Because little is known about the effects of aging on perceived exertion, the aim of this article is to review the key findings from the published literature concerning rating of perceived exertion (RPE) in relation to the developmental level of a subject. The use of RPE in the exercise setting has included both an estimation paradigm, which is the quantification of the effort sense at a given level of exercise, and a production paradigm, which involves producing a given physiological effort based on an RPE value. The results of the review show that the cognitive developmental level of children aged 0-3 years does not allow them to rate their perceived exertion during a handgrip task. From 4 to 7 years of age, there is a critical period where children are able to progressively rate at first their peripheral sensory cues during handgrip tests, and then their cardiorespiratory cues during outdoor running in an accurate manner. Between 8 and 12 years of age, children are able to estimate and produce 2-4 cycling intensities guided by their effort sense and distinguish sensory cues from different parts of their body. However, most of the studies report that the exercise mode and the rating scale used could influence their perceptual responsiveness. During adolescence, it seems that the RPE-heart rate (HR) relationship is less pronounced than in adults. Similar to observations made in younger children, RPE values are influenced by the exercise mode, test protocol and rating scale. Limited research has examined the ability of adolescents to produce a given exercise intensity based on perceived exertion. Little else is known about RPE in this age group. In healthy middle-aged and elderly individuals, age-related differences in perceptual responsiveness may not be present as long as variations in cardiorespiratory fitness are taken into account. For this reason, RPE could be associated with HR as a useful tool for monitoring and prescribing exercise. In physically deconditioned elderly persons, a rehabilitation training programme may increase the subject's ability to detect muscular sensations and the ability to utilise these sensory cues in the perception of effort. RPE appears to be a cognitive function that involves a long and progressive developmental process from 4 years of age to adulthood. In healthy middle-aged and elderly individuals, RPE is not impaired by aging and can be associated with HR as a useful tool to control exercise intensity. While much is known about RPE responses in 8- to 12-year-old children, more research is needed to fully understand the influence of cognitive development on perceived exertion in children, adolescents and elderly individuals.

Adolescent↗
PubMed1978

Influence of local and central factors in dominating rated perceived exertion during physical work.

The literature suggests two major factors determine rated perceived exertion during physical work. These two factors are a local factor, i.e., sensations or feelings of strain in the working muscles and/or joints; and a central factor, i.e., sensations or feelings primarily associated with the cardiorespiratory systems. In some experiments heart rate and minute ventilation (central vactors) appear to be the dominant cues for rated perceived exertion, while in others, local factors such as blood lactate concentration and muscular discomfort seem to be the prominent cues. However, it appears that when a particular cue is accentuated by either elevated rate, concentration or value over others it can dominate the over-all rating of perceived exertion. After evaluating the existing literature, a model has been introduced to evaluate differentiated ratings of perceived exertion (local and central) in comparison to the over-all measure. This model may help aid in a better understanding of the mechanisms by which the subjective perception of exertion is determined during different types of physical work.

Catecholamines↗
PubMed1996

Physiological correlates with perceived exertion during deep water running.

The purpose of this study was to investigate the relationship between perceived exertion and physiological variables during deep water running. Deep water running to VO2 peak was performed in 3-min. stages at leg speeds controlled by a metronome. VO2 and heart rate were continuously monitored by open circuit spirometry and radiotelemetry. Perceived exertion was measured using Borg's 6 to 20-point scale. Multiple regression analysis with a forward solution was used to establish the relations of the measures of perceived exertion with the measures of oxygen uptake, carbon dioxide production, pulmonary ventilation, respiratory exchange ratio, and respiratory rate. %VO2 max was the most important variable predicting perceived exertion. Men and women (ns = 12) reported using different sensory cues to perceive exertion during deep water running.

Adult↗
PubMed1998

A submaximal treadmill test for developing target ratings of perceived exertion for outpatient cardiac rehabilitation.

For patient populations whose heart rates cannot be used to regulate exercise intensity, the Borg Rating of Perceived Exertion (RPE) Scale is the preferred way to prescribe exercise intensity. Individual perceptual variations are best quantified by measuring perceptual intensity during maximal exercise testing; however, many situations require a submaximal protocol. Here, a submaximal treadmill procedure for establishing individualized target Ratings of Perceived Exertion is described. Target ratings of exertion were developed for outpatient cardiac rehabilitation patients using the new method and compared to target Ratings of Perceived Exertion obtained using standard techniques. A total of 144 target ratings at intensities ranging from 50% to 85% VO2max were compared. Over-all, the average difference between the two methods was 0.27 units and was not significant at any intensity. Therefore, the Treadmill Slope Method appears to be a valid submaximal test for generating target Ratings of Perceived Exertion for outpatient cardiac rehabilitation patients.

Ambulatory Care↗
PubMed1999

Regulation of exercise intensity using ratings of perceived exertion during passive visual distraction.

The purpose of this investigation was to determine if passive visual distraction altered ability to regulate exercise intensity as, assessed by ratings of perceived exertion during a 30-min. treadmill run. 10 trained females (VO2max, 52.7 ml.kg-1.min.-1) performed a graded exercise test on a treadmill to assess maximal aerobic power and rating of perceived exertion, oxygen uptake (VO2), heart rate, and running velocity at the 2.5 mmol.L-1 blood lactate concentration. Subjects then used the target rating of perceived exertion to regulate exercise intensity during a control condition, and two treatment runs with passive visual distractions. During the treatment sessions, the subjects ran on a treadmill while viewing a high-action or a low-action video with no audio. The subjects were allowed to adjust the treadmill speed throughout the run to maintain the target rating of perceived exertion; however, subjects were not allowed to view the speed setting. There were no significant differences in blood lactate concentration among the conditions for the control, low action, high action, or graded exercise test (p < or = .05). No significant differences in VO2 or running velocity were found within or among the 30-min. treatment runs and the graded exercise test. Heart rate at 5 min. of exercise during control (158 +/- 3 b.min.-1), low action (158 +/- 3 b.min.-1), and high action (159 +/- 2 b.min.-1) was significantly lower than the graded exercise test (169 +/- 3 b.min.-1). Based on the data collected, visual passive distraction did not alter regulation of intensity using ratings of perceived exertion during a 30-min. treadmill run.

Adult↗