SEARCH · PubMed Health

Results for “EXERTION”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources

PubMed1999

Clinical and angiographic characteristics of exertion-related acute myocardial infarction.

CONTEXT: Vigorous physical exertion transiently increases the risk of acute myocardial infarction (MI), but little is known about the clinical characteristics of exertion-related MI. OBJECTIVE: To compare the clinical and angiographic characteristics of patients who had an exertion-related acute MI vs those who experienced an MI not related to exertion. DESIGN AND SETTING: Prospective observational cohort study of patients with an acute MI referred to a tertiary care hospital for primary angioplasty. PATIENTS: Of 1048 patients with acute MI, 640 (64 who experienced an exertion-related MI and 576 who did not) were selected for treatment with primary angioplasty and admitted between August 1995 and November 1998. MAIN OUTCOME MEASURES: Clinical characteristics of the patients, including their habitual physical activity (determined by the Framingham Physical Activity Index and the Lipid Research Clinic Physical Activity Questionnaire), angiographic findings during coronary angiography, and the relative risk (RR) of MI during exertion. RESULTS: Patients who experienced exertion-related MI were more frequently men (86% vs 68%), hyperlipidemic (62% vs 40%), and smokers (59% vs 37%), were more likely to present with ventricular fibrillation (20% vs 11%), Killip classification III or IV heart failure (44% vs 22%), single-vessel disease (50% vs 28%), and a large thrombus in the infarct artery (64% vs 35%) and were more likely to be classified as having very low or low activity (84% vs 66%). The RR of experiencing an MI during exertion was 10.1 times greater than the risk at other times (95% confidence interval [CI], 1.6-65.6), with the highest risk among patients classified as very low active (RR, 30.5; 95% CI, 4.4-209.9) and low active (RR, 20.9; 95% CI, 3.1-142.1). CONCLUSION: These results show that exertion-related MIs occur in habitually inactive people with multiple cardiac risk factors. These individuals may benefit from modest exercise training and aggressive risk-factor modification before they perform vigorous physical activity.

Cardiac Catheterization↗

PubMed2006

Physical exertion, exercise, and sudden cardiac death in women.

CONTEXT: Exercise is associated with a lower risk of cardiovascular events but may transiently increase the risk of ventricular arrhythmias. Its short-term and long-term associations with risk of sudden cardiac death among women are unclear. OBJECTIVES: To compare the risk of sudden cardiac death in women during moderate to vigorous exertion with the risk of sudden cardiac death during lighter or no exertion; and to assess the long-term association between moderate to vigorous exercise and sudden cardiac death. DESIGN, SETTING, AND PARTICIPANTS: Prospective, nested case-crossover study of 288 cases of sudden cardiac death within the Nurses' Health Study (1980-2004); and a prospective cohort analysis of 69,693 participants without prior cardiovascular disease followed up from 1986-2004. MAIN OUTCOME MEASURE: Risk of sudden cardiac death associated with moderate to vigorous exertion. RESULTS: The absolute risk of sudden cardiac death associated with moderate to vigorous exertion was exceedingly low at 1 per 36.5 million hours of exertion. In case-crossover analyses, the risk of sudden cardiac death was transiently elevated during moderate to vigorous exertion (relative risk [RR], 2.38; 95% confidence interval [CI], 1.23-4.60; P = .01) compared with the risk during lesser or no exertion. Habitual moderate to vigorous exertion modified this transient risk (P = .005 for interaction) and the risk was no longer significantly elevated among those who exercised 2 or more hours per week. In the cohort analyses, an increasing amount of moderate to vigorous exercise was associated with a lower long-term risk of sudden cardiac death in age-adjusted and multivariable models that excluded biological intermediates (P = .006 for trend). This relationship was attenuated when biological intermediates were included (P = .06 for trend); however, the reduction in risk remained significant among women who exercised 4 or more hours per week (adjusted RR, 0.41; 95% CI, 0.20-0.83; P = .01) compared with women who did not exercise. CONCLUSIONS: These prospective data suggest that sudden cardiac death during exertion is an extremely rare event in women. Regular exercise may significantly minimize this small transient risk and may lower the overall long-term risk of sudden cardiac death.

Adult↗

PubMed2000

Triggering of sudden death from cardiac causes by vigorous exertion.

BACKGROUND: Retrospective and cross-sectional data suggest that vigorous exertion can trigger cardiac arrest or sudden death and that habitual exercise may diminish this risk. However, the role of physical activity in precipitating or preventing sudden death has not been assessed prospectively in a large number of subjects. METHODS: We used a prospective, nested case-crossover design within the Physicians' Health Study to compare the risk of sudden death during and up to 30 minutes after an episode of vigorous exertion with that during periods of lighter exertion or none. We then evaluated whether habitual vigorous exercise modified the risk of sudden death that was associated with vigorous exertion. In addition, the relation of vigorous exercise to the overall risk of sudden death and nonsudden death from coronary heart disease was assessed. RESULTS: During 12 years of follow-up, 122 sudden deaths were confirmed among the 21,481 male physicians who were initially free of self-reported cardiovascular disease and who provided information on their habitual level of exercise at base line. The relative risk of-sudden death during and up to 30 minutes after vigorous exertion was 16.9 (95 percent confidence interval, 10.5 to 27.0; P<0.001). However, the absolute risk of sudden death during any particular episode of vigorous exertion was extremely low (1 sudden death per 1.51 million episodes of exertion). Habitual vigorous exercise attenuated the relative risk of sudden death that was associated with an episode of vigorous exertion (P value for trend=0.006). The base-line level of exercise was not associated with the overall risk of subsequent sudden death. CONCLUSIONS: These prospective data from a study of U.S. male physicians suggest that habitual vigorous exercise diminishes the risk of sudden death during vigorous exertion.

Adult↗

PubMed1996

Self-reported physical exertion in geriatric care. A risk indicator for low back symptoms?

STUDY DESIGN: The study group consisted of 131 female nursing aides who took part in an intervention program with physical training or education. Assessments were performed before the intervention program and after 6 months. At follow-up evaluation, 91 nursing aides remained in the study. OBJECTIVES: To examine if perceived physical exertion was a risk indicator for low back symptoms, and to examine the relationship between perceived physical exertion, aerobic capacity, back endurance, psychological demands, and job control. SUMMARY OF BACKGROUND DATA: Perceived physical exertion frequently is assessed in epidemiologic studies concerning low back symptoms. More information about the relationship between perceived exertion, other potential risk indicators, and symptoms may provide opportunities for effective prevention of symptoms. METHODS: Assessments were obtained by questionnaires and physical capacity tests. RESULTS: The nursing aides who reported high physical exertion and were 45 years of age or older were at greater risk in the follow-up period for reporting new symptoms, continued symptoms with the same intensity, or more intense symptoms from the low back (rate ratio, 3.01; 95% confidence interval, 1.1-8.2). The exposure variable correlated most strongly (r = 0.4) with perceived physical exertion was psychological demands. CONCLUSIONS: The results indicated being aged 45 years or older, combined with high perceived physical exertion, was a risk indicator for low back symptoms. A relationship between perceived physical exertion and psychological demands was observed, but there was no influence of physical capacity on perceived physical exertion.

Adult↗

PubMed2006

Perceived exertion in physical activity and risk of gestational diabetes mellitus.

BACKGROUND: Physical activity has been associated with decreased risk of gestational diabetes mellitus. Expanding on 2 previously published analyses of absolute exertion measures (time spent and energy expended), we assessed the relation between perceived exertion during usual prepregnancy recreational physical activity and gestational diabetes. METHODS: We analyzed data from a Washington State 1998-2002 case-control study (216 cases, 472 controls) and a 1996-2002 prospective cohort study (897 participants) separately. We used logistic regression models to derive odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Among case-control participants, risk of gestational diabetes was markedly lower for women who reported very strenuous to maximal exertion in usual activity during the year before pregnancy versus those who reported negligible or minimal exertion (adjusted OR = 0.19; CI = 0.15-0.50). There was a direct inverse relation between perceived exertion and risk of gestational diabetes. This relation was also evident among the subset of participants who did not meet physical activity guidelines in the year before pregnancy. Similarly, the OR among cohort participants reporting very strenuous to maximal exertion was 0.57 (0.24-1.37) versus those reporting negligible to moderate exertion. CONCLUSIONS: These results suggest that risk of gestational diabetes is inversely related to the exertion perceived during recreational physical activity in the year before pregnancy. Perceived exertion may be a valuable addition to behavior and fitness measures in assessing relations between physical activity and pregnancy-related health outcomes.

Adult↗

PubMed1988

Impaired left ventricular function during exercise in coronary artery disease and exertional hypotension.

To characterize the hemodynamic abnormalities responsible for exertional hypotension coronary artery disease, we studied 11 patients with exertional hypotension during supine cycle ergometer exercise, defined as greater than 10 mm Hg decrease in systolic blood pressure during exercise, and 11 patients without exertional hypotension (controls). Patients were similar with respect to age, left ventricular ejection fraction at rest, and the intensity of exercise relative to maximal treadmill exercise capacity. Peak exercise ejection fraction, determined by radionuclide ventriculography, was significantly lower in patients with, than in those without exertional hypotension (50 +/- 3 vs. 56 +/- 3%; p less than 0.025). Ejection fraction and stroke volume decreased with exercise in patients with exertional hypotension but not in the controls even though changes in end-diastolic volume and mean blood pressure were similar in both groups. Peak exercise systolic blood pressure and rate pressure product were significantly lower in the patients with exertional hypotension than those without. The exercise-induced regional left ventricular contraction abnormalities were more prominent, extensive and frequent in patients with exertional hypotension than controls. Impairment of left ventricular contractile function was further evident by an abnormal end-systolic volume-systolic blood pressure relation in patients with exertional hypotension. These patients attained a much smaller increase in systolic blood pressure compared with controls despite no statistically significant differences in end-systolic volume response to exercise. These findings suggest that exertional hypotension in patients with ischemic heart disease is associated with exercise-induced left ventricular systolic dysfunction secondary to extensive myocardial ischemia.

Coronary Disease↗

PubMed1993

Perceived exertion. Antecedents and applications.

The field of perceived exertion has largely concerned itself with the problem of identifying the primary antecedents to this psychophysiological phenomenon. A vast literature has evolved addressing this problem, but it is fraught with contradictions. At this stage a comprehensive theory of perceived exertion does not exist. It is generally accepted that perception of exertion is dominated by physiological determinants. Physiological sensory cues have been separated into 2 categories: local factors (sensations from the working muscles and joints), and central factors (sensations from the cardiopulmonary system). Major reviews in this area generally agree that local factors dominate perception of exertion. Recent work in perceived exertion has placed an emphasis on examining the contributing psychological factors. Research into the psychological factors affecting perceived exertion has been highly fragmented with no apparent theoretical framework as a base. At the same time it is clear that an integration of psychological and physiological variables is required to obtain theoretically meaningful knowledge of this multidimensional construct. The assumed dominance of physiological factors has been challenged by the contention that in field situations, in which a variety of social psychological influences operate, psychological determinants of perceived exertion may be vastly more influential than previously estimated. Identification of the primary determinants of perceived exertion and knowledge of how these factors are integrated is vital for a concrete theory of perceived exertion to evolve.

Exercise Therapy↗

PubMed1996

[Onset of dyspnea on exertion in elderly and young patients with congestive heart failure].

We previously reported that dyspnea on exertion in patients with congestive heart failure was not associated with pulmonary function ar rest, but was associated with the appearance of the anaerobic threshold and with the respiratory compensation point during exercise. Here we described a study of the influence of aging on the onset of dyspnea on exertion in elderly and in young patients with congestive heart failure. A total of 53 patients were studied: 35 were less than 65-year-old (average age, 47-year-old; 19 men and 16 women) and 18 were more than 65-year-old (average age, 70-year-old; 13 men and 5 women). All patients underwent maximal graded exercise testing on a bicycle ergometer. The workload increased according to a ramp protocol, and perceived exertion was evaluated with the Borg scale. The anaerobic threshold, the respiratory compensation point, and the peak VO2 were recorded. Values of 13 (somewhat hard) and 17 (very hard) on the Borg scale were considered to mark the start of dyspnea on exertion and an increase in dyspnea on exertion respectively. In the young patients, dyspnea on exertion began at about the time that the anaerobic threshold was reached, and it increased at about the time that the respiratory compensation point was reached. In contrast, elderly patients dyspnea on exertion began 70 seconds after the anaerobic threshold was reached, and it increased 30 seconds after the respiratory compensation point was reached. The VO2 at the start of dyspnea on exertion and the VO2 at the anaerobic threshold correlated more closely in the young patients than in the old patients. The same was true of the VO2 at the time that dyspnea on exertion increased and the VO2 at the respiratory compensation point. These findings suggest that elderly patients with congestive heart failure are less sensitive to the stimuli that cause dyspnea than are young patients.

Adolescent↗

PubMed1994

A characteristic change in ventilation mode during exertional dyspnea in patients with chronic heart failure.

Although exertional dyspnea is an important symptom limiting daily lives in patients with chronic heart failure, there is no objective assessment of this symptom. To characterize the exertional dyspnea, ventilatory responses to exercise were studied in relation to exertional dyspnea. Gas exchange data were obtained during a maximal bicycle exercise in 43 patients with chronic heart failure and 20 normal subjects. In addition to standard ventilatory variables, the ventilation mode was assessed from the tidal volume-ventilation rate (VT-f) relationship. The exercise was performed again after sublingual administration of 5 mg of isosorbide dinitrate. In normal subjects, the f and VT increased almost proportionally with exercise intensity. In 17 (85 percent) of 20 patients with exertional dyspnea, the VT-f relationship abruptly lost linearity at the onset of exertional dyspnea. This change resulted from an inadequate increase in VT and a further increase in f. In 8 of these 17 patients, isosorbide dinitrate improved exertional dyspnea with normalization of the VT-f relationship; however, in 9 patients whose dyspnea was not improved, the abnormal VT-f relationship was unaltered. Only 2 (9 percent) of 23 patients without exertional dyspnea showed the abnormal VT-f relationship. Other ventilatory variables were not different between patients with and without dyspnea. Thus, exertional dyspnea is characterized by simultaneous appearance of rapid and shallow ventilation. The VT-f relationship appears to be a simple and useful objective assessment of exertional dyspnea in patients with chronic heart failure.

Dyspnea↗

PubMed2005

Cardiac risk of coronary patients after reintegration into occupations with heavy physical exertion.

The job related reintegration of patients with coronary artery disease (CAD) is a central part of cardiac rehabilitation. However, specific occupational demands like jobs with heavy physical exertion (> 6 METs) could increase the cardiovascular risk because the relative risk for acute myocardial infarction (MI) and cardiac death is temporarily elevated after vigorous exertion ("hazard period"). Thus, in 2001 any male patient with proven CAD who performed a job with heavy exertion until the occurrence of an index event (MI/ACS, any interventional or surgical revascularization measure) received a questionnaire after an average of 20 months. Complete data were available in 108 from 119 included patients (90.8%), aged 51.8+/-7.8 years. Ejection fraction was 61.5+/-13.1% and the functional capacity at the time of hospital discharge averaged 130.1+/-31.2 W. 75% of the patients had a previous MI and 59.3% underwent bypass surgery. During follow-up the previous job with heavy exertion was performed over a cumulated time of 74 years. The aim of the study was to compare the observed and the expected incidence of MI and cardiac death with and without job performance. The expected ("basal") risk for MI and cardiac death without heavy physical exertion was determined from pooled study results and assumed to be 5.2% per year. The combined risk due to performing an occupation with strenuous exertion can be calculated from time periods with and without working hours and amounts to 11.9%. There could be expected 0.119 . 74=8.8 cardiac events related to the job. In contrast, 5 MIs (4 NSTEMI, 1 STEMI) were observed (6.8%). The relative risk for an expected event compared to the basal risk without heavy exertion was 2.3 (95% CI: 0.7-7.4). The relative risk for the observed cardiac events amounts to 1.3 (95% CI: 0.4-4.8). The lower observed risk is probably due to the high grade of physical fitness in this patient group. In spite of several limitations, our study showed no convincing evidence for increasing the cardiac risk of patients with CAD performing occupations with heavy physical exertion. Because of the importance of this prognostic finding, a representative and prospective study is strongly required.

Coronary Artery Disease↗

PubMed2003

Perceived exertion and maximal quadriceps femoris muscle strength during dynamic knee extension exercise in young adult males and females.

The objectives of the present study were to: (1) examine perceived exertion across different target voluntary-contraction intensities; (2) compare perceived exertion ratings with actual target intensities, and (3) compare perceived exertion ratings between males and females. Subjects for this study included 30 healthy, college-aged male (n=15) and female (n=15) volunteers. All subjects were free of orthopedic, cardiopulmonary, systemic and neurological disease. Subjects were evaluated for their one-repetition maximum (1-RM) during inertial knee extension exercise. All subjects then completed, in a random order, two sub-maximal inertial contractions at 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90% of their 1-RM. Perceived exertion was measured by asking subjects to provide a number that corresponded to the feelings in their quadriceps after completion of the two repetitions, by viewing a modified category-ratio (CR-10) scale. The results showed that males lifted a significantly greater absolute (P<0.05) and relative (P<0.05) amount of mass than females; allometric-modeled strength values also demonstrated significant sex differences. The results revealed a significant intensity main effect (P<0.001) but no significant gender main effect (P=0.97) nor intensity-by-gender interactions (P=0.50) for the perceived exertion responses. The findings demonstrated that perceived exertion was significantly (P<0.05) lower than the specific expected values on the CR-10 scale from 10% to 60% of 1-RM, but was not different from 70% to 90% 1-RM. The results revealed that the increase in perceived exertion was fit to both linear and quadratic trends, and that the exponent of the power function was found to be 1.437 (SD 0.22) for the males, and 1.497 (0.295) for the females. The major findings demonstrate that although males were able to lift more absolute and relative mass than females, the perceptual response to relative load was similar between genders. The increase in perceived exertion, as a function of relative load, showed a strong linear trend; however, enhanced perceptual sensitivity at high contraction intensities was evident from the positively accelerating power function.

Adult↗

PubMed2000

Fitness and perceived exertion in patients with fibromyalgia syndrome.

OBJECTIVE: The aim of this study was to evaluate the cardiorespiratory fitness and perceived exertion of female patients with fibromyalgia syndrome (FMS) compared with that of healthy female subjects. DESIGN AND SUBJECTS: This was designed as a cross-sectional case-control study, with a consecutive sample of 30 female patients with FMS and an age-matched control group of 67 healthy female subjects. SETTING: This study was conducted at the multidisciplinary pain center of a university hospital in a city of more than 1 million inhabitants. OUTCOME MEASURES: A cardiorespiratory fitness index (PWC65%/kg) and an original perceived exertion index (B65%) were obtained from the heart rates and perceived exertions scored on a 10-point Borg scale during a submaximal cycle ergometer test. Average indexes for the FMS patients and control subjects were compared. RESULTS: The mean cardiorespiratory fitness index of the FMS patients was not significantly different from that of the controls. The mean perceived exertion index in the FMS patients was significantly greater than that of the controls, meaning that the FMS patients systematically reported higher ratings of perceived exertion during exercise. CONCLUSIONS: Cardiorespiratory fitness, as expressed by a submaximal work capacity index, seems normal in female patients with FMS compared with age- and sex-matched healthy individuals. The fact that FMS patients overscore their perception of exertion may be due to a greater overlap of peripheral pain and perceived exertion perceptions during exercise. This observation should be noted when using perceived exertion scores to prescribe and monitor exercise in FMS patients.

Adult↗

PubMed2002

Exertional dizziness and autonomic dysregulation.

OBJECTIVES: To define the clinical characteristics and treatment of dizziness induced by physical exertion and to investigate autonomic nervous system function in exertional dizziness. STUDY DESIGN: Retrospective case series from a review of 1400 patients evaluated for dizziness at a neurotology referral center, identifying those with predominantly exertional symptoms. METHODS: Records of patients with exertional dizziness were screened to eliminate those with known vestibular deficits, cardiopulmonary illnesses, and psychiatric disorders. The clinical characteristics, evaluation results, and treatment of nine patients with purely exertional dizziness were described. RESULTS: The cohort included 4 male and 5 female patients (age range, 13-53 y) with symptoms for 1 to 8 years. Only one patient had a history of autonomic symptoms: phlebotomy-induced syncope in childhood. No patient was taking medications that caused dizziness or orthostasis. All patients experienced "spacey" or "foggy" head sensations without vertigo during exertion. Provocative activities ranged from standing upright for extended periods to running and swimming. On examination, voluntary hyperventilation provoked moderate symptoms in all patients (without nystagmus or anxiety), although no patient had spontaneously occurring, hyperventilation-related complaints. Seven patients underwent autonomic testing. Tilt table tests (n = 5) produced severe symptoms in one patient and mild symptoms in two patients. Sodium lactate infusions (n = 6) provoked marked symptoms in four patients and moderate symptoms in one patient. All were treated for autonomic dysregulation. Seven patients improved substantially and resumed all of their premorbid activities. Two improved slightly. CONCLUSIONS: In nine patients with exertional dizziness, autonomic challenges were provocative, and medications for autonomic dysregulation were effective. Exertional dizziness may be a clinical manifestation of autonomic nervous system dysregulation.

Adolescent↗

PubMed2005

Epidemiological analysis of factors influencing an episode of exertional rhabdomyolysis in high school students.

BACKGROUND: An episode of rhabdomyolysis occurred after an endurance test in high school students in Taipei County in November 2003. PURPOSE: To determine the incidence, outcome, and risk factors in an episode of exertional rhabdomyolysis in high school students. STUDY DESIGN: Descriptive epidemiology study. METHODS: We enrolled all 225 high school students who had performed an endurance test. Using data from retrospective questionnaires, we estimated the incidence and assessed risk factors of exertional rhabdomyolysis among these students. Multiple logistic regression was used to determine risk factors associated with exertional rhabdomyolysis. RESULTS: The completed questionnaire was returned by 70% (157 of 225) of the students. Of these, 43.3% (68 of 157) were identified as having exertional rhabdomyolysis, and the incidence was not statistically different between male and female students (P = .49). Dark urine was noted in only 25% of the students. None of the students developed acute renal failure. The risk of exertional rhabdomyolysis was significantly higher in those students who had not exercised 1 day before the endurance test (odds ratio [OR], 6.10; 95% confidence interval [CI], 2.00-18.00) and those who had performed postexercise stretching of the legs (OR, 3.13; 95% CI, 1.28-7.69) or performed complete squats during the test (OR, 3.21; 95% CI, 1.12-10.00). There were no statistically significant differences in gender, body mass index, presence of flulike symptoms, previous exercise routine, and medication history between students with or without exertional rhabdomyolysis. CONCLUSION: Our findings suggest that exertional rhabdomyolysis is not uncommon in strenuous eccentric exercise in both men and women, but the risk of developing acute renal failure is very low. Exercise 1 day before eccentric exercise was significantly associated with a reduced risk of exertional rhabdomyolysis, whereas postexercise stretching of the involved extremities might increase the risk.

Adolescent↗

PubMed2004

Gender differences in perceived exertion during fatiguing knee extensions.

PURPOSE: To examine gender differences in knee extensor strength, fatigue, and perceived exertion during a single set of continuous dynamic knee extensor contractions. METHODS: Fifteen men and 15 women were evaluated for their one-repetition maximum (1RM) during a single-leg, inertial knee extension with their right leg. All subjects then completed a single set of repeated knee extensions with a load equivalent to 50% of their 1RM to failure. Subjects lifted the weight by performing a knee extension, held the weight with the knee extended for 1-2 s, and then lowered the weight in a slow and controlled manner. Perceived exertion was measured after completion of each repetition, by viewing a modified Borg category-ratio (CR-10) scale. Perceived exertion responses were standardized across subjects via linear interpolation and power function modeling. The linear interpolated perceived exertion estimates were then examined for linear, quadratic, and cubic trends across the repetitions. RESULTS: Men lifted a significantly greater amount of mass than women, when corrected for body mass. Men and women did not differ significantly in the number of repetitions performed to failure. Women displayed significantly higher power function exponents for the perceived exertion response than men (0.72 +/- 0.16 and 0.57 +/- 0.16, respectively) and demonstrated statistically nonsignificant greater increases in perceived exertion than men across the repetitions. CONCLUSIONS: The major findings of this study indicated that: 1) men inherently possessed greater knee extensor strength than women; 2) submaximal fatiguing knee extensor performance did not differ between genders; 3) model selection had a significant impact on standardizing perceived exertion estimates; and 4) subtle gender differences in the perceived exertion response may have existed during submaximal, fatiguing resistance exercise.

Adult↗

PubMed2001

The influence of sensory cues on the perception of exertion during exercise and central regulation of exercise performance.

The perception of effort during exercise and its relationship to fatigue is still not well understood. Although several scales have been developed to quantify exertion Borg's 15-point ratings of perceived exertion (RPE) scale has been adopted as a valid and reliable instrument for evaluating whole body exertion during exercise. However, Borg's category-ratio scale is useful in quantifying sensations of exertion related to those variables that rise exponentially with increases in exercise intensity. Previous research has examined the extent to which afferent feedback arising from cardiopulmonary and peripheral variables mediates the perception of exertion. However, the literature has not identified a single variable that consistently explains exertion ratings. It is concluded that effort perception involves the integration of multiple afferent signals from a variety of perceptual cues. In a process defined as teleoanticipation, the changes in perceived exertion that result from these afferent signals may allow exercise performance to be precisely regulated such that a task can be completed within the biomechanical and metabolic limits of the body. The accuracy with which individuals can regulate exercise intensity based upon RPE values, the decrease in muscle recruitment (central drive) that occurs before fatigue, and the extent to which perceived exertion and heart rate can be altered with hypnosis and biofeedback training all provide evidence for the existence of such a regulatory system. Future research is needed to precisely quantify the extent to which efferent feedforward commands and afferent feedback determine pacing strategies such that an exercise event can be completed without irreversible tissue damage.

Biomechanical Phenomena↗

PubMed2002

Ratings of perceived exertion during low- and high-intensity resistance exercise by young adults.

Ratings of perceived exertion (RPE) are commonly used to monitor the intensity of aerobic exercise. Whether ratings of perceived exertion can be used similarly during resistance exercise is unclear. To examine this question, perceived exertion was measured at 30% and 90% of the one-repetition maximum (1-RM), while holding work constant between intensities. Ratings for the active muscles and for the overall body were examined during both intensities. 10 male (age=23.2 +/- 3.6 yr.) and nine female (age=21.8 +/- 2.7 yr.) volunteers underwent a one-repetition maximum procedure for each of the following exercises: bench press, leg press, latissimus pull down, triceps press, biceps curl, shoulder press, and calf raise. All subjects then completed two experimental trials on separate days. The high-intensity trial consisted of one set of five repetitions at 90% of the one-repetition maximum. The low-intensity trial consisted of one set of 15 repetitions at 30% of the one-repetition maximum. Active muscle and overall body ratings of perceived exertion were obtained immediately at termination of each of the seven exercises at both intensities. A two-factor (RPE x Intensity) repeated-measures analysis of variance was performed separately for each exercise. Both active muscle and overall body ratings of perceived exertion were higher (p<.01) for the high-intensity trial than for the low-intensity trial. Active muscle ratings were higher (p<.01) than overall body ratings for all exercises. Ratings of perceived exertion during resistance exercise are related to intensity of the resistance exercise (percentage of the one-repetition maximum). This information suggests that ratings of perceived exertion can provide information regarding the intensity of resistance exercise. Furthermore, sensations of exertion in the active muscles during resistance exercise are greater than sensations for the overall body.

Adult↗

PubMed2004

Anchoring procedures in reliability of ratings of perceived exertion during resistance exercise.

Although the validity of perceived exertion as a method of monitoring the intensity of resistance exercise has been established, little is known about the test-retest reliability of ratings of perceived exertion during resistance exercise. Specifically, it is unknown whether the use of different anchoring procedures influences the reliability of ratings of perceived exertion. 30 men were assigned to an Exercise, Memory, or combined Exercise and Memory anchoring group. Participants completed an assessment of maximal leg-extension strength and were introduced to the Borg 15-category rating of perceived exertion scale through anchoring procedures that varied across groups. During two sessions of resistance exercise, participants rated active muscle perceived exertion after performing one repetition of the leg-extension exercise at 40%, 50%, 60%, 70%, 80% and 90% of the one-repetition maximum. A three-factor (Group x Intensity x Session) analysis of variance was performed to examine the perceived exertion data. Perceived exertion increased significantly (p<.01) with increasing exercise intensity in all groups and in both sessions. Mean ratings did not differ significantly among groups. Reliability was assessed for each group. Intraclass correlation coefficients ranged from .07 to .80 and percent agreement ranged from 60% to 90%. The results indicate that the reliability of ratings of perceived exertion during resistance exercise is acceptable regardless of the type of anchoring procedures used.

Adult↗