Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “EXERTION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 325 records · Page 18Linked to original sources
PubMed1998

Comparison of image analysis, exertion force, and behavior measurements for use in the assessment of beef cattle responses to hot-iron and freeze branding.

Thirty-three steers (328 +/- 2 kg) from a total of 300 animals were randomly selected for a comparison of techniques designed to quantify the behavioral response to painful procedures. The steers were randomly assigned to freeze-branding, (F), hot-iron branding (H), and sham branding (S) treatments. The responses of all steers were videotaped to quantify the amount and intensity of head movements during branding. In addition, the force that steers exerted on the headgate and squeeze chute during branding was recorded using strain gauges and load cells. Behaviors believed to be indicative of pain (tail-flicking, kicking, falling, and vocalizing) were also recorded during branding. These techniques were compared for their effectiveness in measuring behavioral responses of steers during branding. Hot-iron-branded steers had greater maximum and average head movement distances and velocities than F or S steers (P < .05), and F steers only had greater maximum values than S animals (P < .05). The maximum exertion forces obtained from headgate load cells were also greater in H than in F or S steers (P < .05); however, no differences were observed between H and F treatments for squeeze load cell or headgate strain gauge data. Hot-iron-branded steers had the greatest incidence of tail-flicks, kicks, falls in the chute, and vocalizations, and S steers had the least. Results indicate that H steers experienced more discomfort at the time of branding than F and S steers, whereas F steers experienced more discomfort than shams. Image analysis was a superior technique for detecting treatment differences compared with exertion force measurements and frequency counts of tail-flicks, kicks, falls, and vocalization during branding.

Animal Identification Systems↗
PubMed1984

Motivation as a factor of perceived exertion in purposeful versus nonpurposeful activity.

Perceived exertion during the performance of purposeful and nonpurposeful activity was studied in 26 women. The subjects acted as their own controls in the performance of both kinds of exercise. The two exercises were jumping rope, defined as a purposeful activity, and jumping in place without a rope, defined as a nonpurposeful activity. In each activity the subjects exercised to reach the subjective point of "very hard work" on the Borg Scale of Perceived Exertion. Duration and cessation of exercise were entirely controlled by the performers. Heart rate responses during and immediately after cessation of exercise, measured by electrocardiographic telemetry, and duration of exercise in seconds were compared for the two types of exercise. Results showed that heart rate increase at a given rate of perceived exertion was significantly higher (.001) for jumping rope. This raises the possibility that workload was inadvertently perceived by the performers to be greater in nonpurposeful activity and provides support for the hypothesis that purposeful activity serves as an intrinsic motivator to the performer.

Adult↗
PubMed1990

Psychophysical scaling with applications in physical work and the perception of exertion.

In studies on work it is important to assess various subjective symptoms, complaints, and annoyances. To measure such symptoms, psychophysical ratio scales may be used, as along with simpler category rating scales. In this paper some of the basic concepts and methods of psychophysics have been described. In the field of heavy physical work and the perception of effort and exertion, one of the most popular methods is the rating of perceived exertion. This scale has been presented together with a new category ratio scale, commonly referred to as the CR-10 scale. Some situations in which it is important to obtain measurements of perceived exertion have also been described in the paper.

Humans↗
PubMed1998

Computer mouse position as a determinant of posture, muscular load and perceived exertion.

OBJECTIVES: This study concerned the influence of 6 positions of the computer mouse on the work table on posture, muscular load, and perceived exertion during text editing. METHODS: An optoelectronic 3-dimensional motion analysis system was used to register the postures of 10 men and 10 women using video display units. Muscular load was also registered (with electromyography), as was perceived exertion (with rating scales). RESULTS: A neutral posture with a relaxed and supported arm showed the least perceived exertion, and the electromyographic results showed low activity in both trapezius muscles in this position. Short operators (all women) showed a numerically higher activity in the 4 examined muscles than the tall operators (all men, except 1). This finding could be related to lower muscle force among women and to anthropometric differences, which also influence biomechanic load moments. Narrow-shouldered operators (8 women and 1 man) and short operators worked with larger outward rotation and abduction of the shoulder in a position of the mouse lateral to the keyboard than the broad-shouldered (7 men and 2 women) and tall operators did. Arm support markedly reduced muscle load in the neck-shoulder region among the operators. CONCLUSIONS: The operators using video display units in this study preferred to use the mouse on a table in a close to relaxed, neutral posture of the arm in combination with arm support. Short and narrow-shouldered operators worked in more strenuous postures of the arm when the mouse was located lateral to the keyboard.

Adult↗
PubMed1999

The effects of rest interval on quadriceps torque and perceived exertion in healthy males.

BACKGROUND: The ability to generate maximal muscular force is dependent upon time mediated mechanisms of fatigue. Interset rest interval length may not only affect force production but may also manifest changes in ratings of perceived exertion (RPE). The purpose of this study was to examine the effects of rest interval on quadriceps torque and RPE during multiple sets of resisted knee extensions. METHODS: 14 healthy male volunteers were assessed for concentric isokinetic quadriceps peak torque, total work, and average power on the Biodex System II Isokinetic Dynamometer at a preset angular velocity of 180 deg.sec-1. Perceived exertion was measured with a modified category-ratio scale (CR-10). Under isometric conditions the perceptual range was anchored with one high and two low anchors. Subjects were randomly assigned to one of two groups: short rest interval (Group 1, 40 sec) and long rest interval (Group 2, 160 sec). All subjects performed 4 sets of 20 maximal isokinetic contractions with an inter-set rest interval that corresponded to their group assignment. Following the completion of each set subjects were asked to assign a rating out of 10 to the feelings in their quadriceps by visually observing a chart of the CR-10 scale. RESULTS: The results demonstrated a significantly greater decline in quadriceps peak torque (p < 0.05), total work (p < 0.05), and average power (p < 0.05) by Group 1 as compared to Group 2. Changes in RPE across the 4 sets of exercise did not show a significant difference between the 2 groups. CONCLUSIONS: The generation of quadriceps torque is a function of rest interval length, whereas perceived exertion appears to be unaffected.

Adult↗
PubMed2001

[Exertional hypertension and sport].

Defining the normal range of blood pressure during exertion is not easy. Each type of exercise induces increased blood pressure that responds to a particular curve, and adaptation modes differ according to age, gender, physical condition, basal blood pressure, etc. The best studied is blood pressure measured on the arm using a cycloergometre. Classical publications established blood pressure curves according to heart rate during exercise. It appears that the best scale of reference for power developed occurs in individuals who can provide a very high degree of effort and in particular, athletes who are in very good training. According to some authors, hypertension on exertion would entail a poor prognosis, even in the absence of resting hypertension. Nevertheless, there is presently no well established therapeutic recommendation concerning exertion hypertension. This approach could depend on resting blood pressure and on the existence of other risk factors. For an athlete, pursuing physical activity is most often encouraged, sometimes after treatment or adjustment of its level.

Blood Pressure↗
PubMed2002

[Acute cardiovascular complications of vigorous physical exertion by untrained persons].

Physical exertion has paradoxical effects: regular physical activity offers protection against cardiovascular diseases, but, on the other hand, it has been shown that strenuous exercise can provoke coronary heart disease and sudden death. The risks of vigorous exertion apply particularly to untrained individuals and persons with a sedentary lifestyle. Physical exertion can cause a myocardial infarction or sudden death in people who were considered perfectly healthy before this event. In most cases, the mechanism of this is probably a rupture at the site of a vulnerable atherosclerotic plaque, with local activation of coagulation. Disturbances in cardiac rhythm may also be a cause of these complications.

Coronary Disease↗
PubMed2004

[Acute liver failure related to the syndrome of exertional heatstroke].

Heatstroke syndrome is a well-described state, which usually occurs in areas with warm climates. Two forms are commonly distinguished: the exertional and the classic heatstroke. Increased serum levels of liver enzymes are often detected in this condition. However, acute hepatic failure following exertional heatstroke is rare. We report a case of a 30 years old man with exertional heatstroke, acute hepatic failure, serious coagulation impairment and a rhabdomyolysis following ten kilometers run. Acute hepatic failure completely developed the forth day of hospitalisation. On the fifth day, the patient fulfilled London criteria for liver transplantation and was referred to the transplantation center for the optimal management assessment. After the conservative management of acute phase, spontaneous recovery of liver functions occurred and the patient finally was not transplanted. 23 days after admission to the hospital, the patient was discharged with residual cholestasis and was followed up on outpatient basis. Serum levels of liver enzyme returned to the normal 3 months after the liver injury. In several cases, the liver failure following heatstroke is reversible and conservative management can be successful. Additionally, in 3 reported cases, emergency liver transplantation for acute hepatic failure due to heatstroke with renal failure and coma showed very poor outcome. Our case demonstrates that conservative management even in patients fulfilling accepted criteria for emergency liver transplantation can be effective and should be considered in similar condition.

Adult↗
PubMed1991

Estimates of Type A behavior do not predict perceived exertion during graded exercise.

Earlier studies have concluded that exercise tolerance during graded stress testing is overestimated in males showing the Type A Behavior Pattern (TABP) because of high motivation and suppressed ratings of perceived exertion (RPE). However, the studies used the Jenkins Activity Survey (JAS) to assess TABP and employed exercise protocols that were unstandardized or uninterpretable for clinical prescription. Because the JAS lacks validity for predicting the criterion Structured Interview (SI) for TABP, the usefulness of concurrent self-report estimates of TABP for predicting RPE during standard exercise testing warrants additional study. During clinical treadmill testing of 86 asymptomatic Caucasian men (45 +/- 9 yr), we examined three standard estimates of TABP (JAS, Bortner, Framingham) as predictors of: 1) the covariance (RPE') of RPE (Borg Category Scale) with VO2 (ml.kg-1.min-1) during 5 min of graded walking (5.47 km.h-1, 2.25%.min-1); 2) VO2 and RPE (11.6 +/- 2.2) at a preferred level of exertion (approximately 65% +/- 10% VO2PEAK); 3) VO2PEAK and RPE at VO2PEAK. Multiple linear regression analyses found no relations (P greater than 0.10) between estimates of TABP and treadmill responses. Discriminant analyses of Type A and Type B groups formed from tertiles consistent with population norms showed no differences (P greater than 0.01) for RPE of treadmill performance. Our findings question prior reports of RPE suppression associated with TABP estimates. We conclude that practically implementable estimates of TABP do not offer useful information for clinical predictions of RPE, preferred exertion level, or VO2PEAK in asymptomatic middle-aged Caucasian men.

Adult↗
PubMed1991

Effects of nicotine on perceived exertion during low-intensity activity.

Nicotine may decrease perceived exertion during physical work, which may be a potentially reinforcing effect of tobacco smoking. This study examined the effects of nicotine on ratings of perceived exertion (RPE) during low-intensity physical activity representative of activity normally engaged in by adult smokers. Ten male and 10 female smokers participated in four morning sessions, one for placebo and each of three nicotine doses (7.5, 15, and 30 micrograms.kg-1), which were administered by measured-dose nasal spray. Using a bicycle ergometer, subjects exercised at each of two lower power outputs (30 and 60 W) before and after nicotine dosing, while RPE and cardiovascular measures of heart rate and systolic and diastolic blood pressure were obtained. Results indicated no significant effect of nicotine on RPE for either males or females. In contrast, nicotine significantly increased each cardiovascular measure during activity, confirming that cardiovascular responses during exercise do not mediate RPE. Thus, nicotine did not influence perception of exertion during low-intensity physical activity.

Adult↗
PubMed1991

Acute renal failure in severe exertional rhabdomyolysis.

During the last 6 years, 7 healthy individuals who were reasonably well acclimatised to physical exertion came under observation with acute renal failure due to exercise induced myoglobinuria. Their mean age was 20 years, and renal failure resulted after cross country run of 10-15 km in 6 cases and long route march of 90 km in 3 days in one case. There was no evidence of effects of heat, dehydration or hypotension. Apart from myoglobinuria and significant urinary sediments, serum aldolase (mean 69.0 SL u/ml) and serum creatinine phosphokinase (mean 120.0 Sigma u/ml) were also elevated. Maximum blood urea and creatinine were 224 mg/dl and 13.9 mg/dl respectively. Hypocalcaemia was noticed in 3 cases, hyperkalaemia in 4 cases and hyperuricaemia in one case during the oliguric phase. One case had features of non-oliguric acute renal failure. All cases recovered though 4 cases required dialysis support. Kidney biopsy in 3 cases showed recovering acute tubular necrosis with eosinophilic material in tubules. Lactate studies in the convalescent period revealed normal response and repeat physical exertion of same severity after 6 months did not reproduce the syndrome. It is concluded that exertional rhabdomyolysis unassociated with heat stress is a rare entity, and with prompt diagnosis and energic management results are rewarding.

Acute Kidney Injury↗
PubMed1991

Self-reported exertion levels on time/activity diaries: application to exposure assessment.

Recent developments in air pollution analysis have focused on methods for collecting data on contaminant levels in the locations actually frequented by people, especially personal monitoring. While there is still much to understand about human exposures, the next advancements will be in the area of dose assessment. This paper discusses the results of a study designed to provide data for linking exposure to dose. Specifically, we used time/activity diaries to collect information on the exertion levels associated with the reported activities. As part of a community health study, 91 children between the ages of 9 and 11 kept diaries over a two-week summer-time period (July 1989) and during a two-week school-time period (September 1989). The diary was also administered for two days to 42 teenagers between the ages of 15 and 17. This paper describes our concerns about interpreting self-reported exertion levels, particularly with respect to the disparity between participant and researcher perception and coding. We then present the distribution of exertion levels associated with children's activities, highlighting seasonal, day-of-week, and age-group differences.

Adolescent↗
PubMed1991

Exertional sudden death in soldiers.

To address the problem of a significant rise in the incidence of exertional sudden death worldwide, the medical records and necropsy reports of all deaths that occurred in the Israel Defence Forces (IDF) during 1974-1986 were scrutinized. Twenty male soldiers, aged 18-29 yr, died suddenly and unexpectedly within 24 h of strenuous exercise. Necropsy results, available for 90% of the subjects, included underlying cardiac disease in 50% and noncardiac causes of death in 33.3%; the cause of death was unidentifiable in 16.7% of the subjects. Prodromal symptoms in 70% of the subjects are presented as a main focus of this investigation. The most frequently reported symptom was exertional or nonexertional syncope in 40% of the subjects. Chest pain, acute gastrointestinal symptoms, or febrile disease were reported in 30% of the cases. The findings of this research suggest that syncope is a major antecedent symptom of exertional sudden death. An attack of syncope in young conditioned individuals should be followed by thorough medical surveillance, and strenuous exercise should be avoided until this procedure is completed. Sports and military officials have the obligation to promote awareness that strenuous exercise should not be performed in the presence of acute gastrointestinal symptoms or febrile illness.

Adolescent↗
PubMed1990

Effect of an exercise program on the perception of exertion in males at retirement.

To describe the association between perception of exertion and exercise, 138 men at retirement, mean age 62.7 years, were studied before and after a one-year program of exercise. VO2max and ratings of perceived exertion (RPE) using the Borg psychophysical scale were determined by a continuous exercise treadmill protocol to fatigue. The men were randomly assigned to an exercise program (n = 69) or control (n = 69). The program consisted of walking or jogging for 30 min, 3 times per week for one year. After training, the activity group showed a significant improvement in VO2max (12%). Linear regression analysis was used to relate RPE to selected physiological measurements for control and activity groups. The equations for the before and after training relationships were compared. Changes in the relationship of RPE vs VO2 and Ve, after training, were not significant for the activity group. However, the control group showed significant changes in these relationships at one year post retirement. For VO2 and Ve, ratings were 1-2 units higher than at time of retirement. Results indicate that perception of a physical task normally changes at retirement such that a given amount of exertion may seem subjectively greater. Results also suggest that a structured exercise program is successful at maintaining perception of task at pre-retirement levels. This maintenance of a low rating of perception may retard a reluctance to be physically active which often accompanies ageing.

Aged↗
PubMed1990

The role of exercise in the etiology of exertional heatstroke.

Exertional heatstroke usually occurs among healthy, fit individuals who are motivated to perform strenuous exercise because of peer pressure, discipline, or athletic competition. In fact, exertional heatstroke deaths among high school athletes in the United States (ranked third only to head and neck injuries and heart failures), and the reluctance of race directors to cancel or postpone mass participation road races during periods of severe heat and humidity, emphasize a continuing need for widespread dissemination of information. The purposes of this symposium are 1) to convey essential information to the members of ACSM who are involved in exercise prescription, patient care, or athletic training; and 2) to disseminate recent scientific theories and research concerning exertional heatstroke.

Body Temperature Regulation↗
PubMed1986

Factors predisposing Army conscripts to knee exertion injuries incurred in a physical training program.

Factors causing predisposition to knee exertion injuries were sought by means of a questionnaire and detailed quantitative physical measurements in 62 healthy Finnish Army conscripts. The subjects consisted of two groups of 18- to 26-year-old conscripts; Group A comprised 34 subjects without knee exertion injuries and Group B, 28 subjects who experienced knee exertion injuries during the first eight weeks of military service. In Group B the extensor mechanism was the most common source of symptoms. The factors found in Group B that differed significantly from those in Group A included increased height (p less than 0.05), increased leg length inequality (LLI) (p less than 0.01), increased passive mediolateral patellar range of motion (PMLPM) (p less than 0.01), and increased knee laxity sum index (LSI) (p less than 0.05).

Adolescent↗
PubMed1979

Forces exerted during exercises on the uneven bars.

The purposes of this study were (1) to develop a technique to measure the force exerted on uneven bars during a gymnast's performance, and (2) to determine the magnitudes of the maximum forces exerted on the bars during normal use. Strain gages, a UV recorder, and motion-picture cameras were used to record the forces exerted against the bars and the motions with which they were associated. Three college gymnasts were used as subjects. Each performed several repetitions of an exercise sequence judged to result in the maximum loading of the bars she might produce under normal conditions. The maximum forces recorded were 3500 N (low bar) and 2140 N (high bar). These values were recorded during a sharp impact between the subject's thighs and the bar during the passage of the subject beneath the bar in a giant swing, respectively. Making due allowance for possible measurement error and for the estimated effects of the bars being used by gymnasts of greater mass than those in this study, it was concluded that bars should be designed to withstand repeated loads of at least 4205 N.

Adult↗
PubMed1980

Muscle metabolites, force, and perceived exertion bicycling at varying pedal rates.

Muscle metabolites, force, and perceived exertion bicycling at varying pedal rates. Med. Sci. Sports Exercise, Vol 12, No. 5, pp. 345-351, 1980. The relative significance of central (VE, Vo2, heart rate) or peripheral (muscle tension, muscle metabolites) factors on perceived exertion (RPE) was investigated with bicycle exercise by varying pedal rate while maintaining a constant power output. Six healthy male subjects exercised at zero load, submaximal (70% Vo2max) and maximal exercise intensities with pedal rates of 40, 60, 80, and 100 rpm. With changing pedal rate and constant power output, there were numerous examples of significant changes in the central factors with no change in RPE and vice versa. Similarly, measures of muscle and blood lactate, NAD, glycogen, ATP, and CP failed to demonstrate any local metabolic factor that correlated with RPE. Force exerted on the pedals and the rate of force generation approximated RPE changes, but the detailed correlation analysis was nonsignificant. None of the central or peripheral factors alone are related to RPE. Thus, RPE must be derived from a number of peripheral and/or central factors in a complex manner.

Adult↗