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At least 1,009 records · Page 56Linked to original sources
PubMed2002

Physiological differences and rating of perceived exertion (RPE) in professional, amateur and young cyclists.

BACKGROUND: The aim of this study is to measure and compare the physiological characteristics and the rating of perceived exertion (RPE) in 72 high level road cyclists of 3 different categories. METHODS: These cyclists were divided in 3 groups according to their age (24 professionals, mean age 26 years, 22 amateurs, 22 years and 26 juniors, 18 years). MEASURES: they carried out a progressive test to exhaustion in a specific cycloergometer, starting with a power output of 100 watts and increasing 50 watts each 4 min. VO2 was measured continuously. At the end of each one of the 4 min steps the subject was asked about his RPE using the 6-20 Borg's scale. RESULTS: Professional cyclists showed a VO2max, VO2 x kg(-1) and a maximum power output significant higher than other groups, while there were no significant differences between amateurs and juniors. VO2 and RPE were significantly different, in all the categories, during high work loads. No significant differences were found between RPE and %VO2max. RPE and heart rate (HR) were significantly different between professionals and juniors. RPE and %HR max were significantly different with low loads, but no with high loads. In the same way, RPE/w and RPE/(w x kg(-1) were significantly different in all categories. CONCLUSIONS: We conclude that professional road cyclists reached a VO2max, VO2max x kg(-1) and a maximum power higher than the other categories; so, therefore, these parameters are good as performance indicators, and RPE is of practical value to prescribe exercise training intensities in each category.

Adolescent↗
PubMed2003

Exertional heatstroke in an infantry soldier taking ephedra-containing dietary supplements.

This is a case report of a highly trained, heat-acclimatized infantry soldier who suffered from exertional heatstroke during a 12-mile road march shortly after taking an ephedra-based supplement. Heatstroke is associated with systemic complications and a high mortality rate if not recognized early. Control of risk factors is key to the prevention of heatstroke. Since there are no clear ergogenic benefits in using ephedra alone, clinicians and military commanders should strongly discourage the use of ephedra-containing substances in active duty soldiers undergoing strenuous exercise.

Adult↗
PubMed1992

Breathlessness predicts perceived exertion in young women with mild asthma.

We examined ratings of breathlessness (BRE) as a predictor of perceived exertion (RPE) during incremental cycling at power outputs of 50, 75, and 100 W. Young females (21 yr +/- 1.9) diagnosed with mild asthma (N = 25) were compared with females having normal lung function (N = 25) matched for age, VO2peak, trait anxiety, activity history (7-d recall), and BMI (kg.m-2). Relative oxygen consumption (%VO2peak), blood lactate concentration, VE.VO2(-1), and state anxiety were statistically controlled in hierarchical multiple linear regression analyses. For each group, %VO2peak explained 60% of the variance in RPE across power outputs (P less than 0.001); R2 was unchanged (P greater than 0.10) with the addition of blood lactate, VE.VO2(-1), and state anxiety. Absolute RPE and BRE did not differ between groups at any power output, but partial standardized (beta) and unstandardized (b) regression coefficients and increases in R2 showed that BRE had a greater effect (P less than 0.01) on RPE for asthmatics [adjusted R2 increased to 0.89; (beta) = 0.75; (b) = 0.79 +/- 0.06] than for controls [adjusted R2 increased to 0.74; (beta) = 0.52; (b) = 0.51 +/- 0.09]. The standard error of the prediction was 0.79 for asthmatics and 1.16 for controls. The prediction of RPE by BRE was not moderated by variation in forced expiratory volume for 1 s (FEV1), forced vital capacity (FVC) or peak inspiratory flow (VI). Physiological responses were similar for the groups, but blood lactate was higher in asthmatics at rest, at each power output, and at VO2peak.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2004

Minimally invasive subcutaneous fasciotomy for chronic exertional compartment syndrome of the lower extremity.

Chronic exertional compartment syndrome of the lower extremity can be debilitating in the active population. Open fasciotomy typically provides a cure or significant improvement in up to 90% of patients, provided that the compartments are adequately released. Cosmetic deformity from the surgery may be a major concern, especially in the young female athlete. A technique for minimally invasive subcutaneous fasciotomy is described that allows adequate compartment release and a favorable cosmetic result.

Chronic Disease↗
PubMed1992

[Rhabdomyolysis in a medical student induced by body-building exercise (rhabdomyolysis following acute muscular exertion)].

A medical student sportsman had been admitted to the hospital because of weakness and painful swelling of the muscle as well as dark urine appearing after carrying out an excessive body-building performance. On the basis of indirect evidences pigmenturia "per exclusionem" was a manifestation of urinary myoglobin excretion. The development of an "acute exertional rhabdomyolysis" was confirmed by the increased serum enzyme levels and myoglobinuria. The outcome of the illness was fortunate, as acute renal failure could be avoided. On the basis of survey of the literature it can be stated, that this presumably frequently occurring, but rarely recognized disease may have importance from clinical, sporting medicine and pathophysiological point of view.

Adult↗
PubMed2004

Chronic exertional compartment syndrome.

Chronic exertional compartment syndrome is an overuse condition affecting primarily active, athletic people. Its etiology is unclear, but several theories have been proposed. The syndrome is characterized by recurrent, often severe muscle compartment pain that occurs with vigorous exercise and subsides with rest. Physical examination usually provides little helpful information. Compartment pressure measurement before and after exercise is the mainstay of objective diagnosis. Conservative management has been highly unsuccessful. Overall, considerable success can be expected from fasciotomy of the involved compartments followed by a rigorous rehabilitation program, though recurrence of symptoms is a reported complication. Recent research efforts have focused on the development of less invasive and more accurate diagnostic modalities and safer and more effective surgical procedures.

Chronic Disease↗
PubMed1992

The validity of regulating exercise intensity by ratings of perceived exertion.

The purpose of this investigation was to examine the regulation of exercise intensity by using Ratings of Perceived Exertion (RPE). The RPE equivalent to 50% and 70% VO2max was estimated by using standard clinical protocols on a treadmill and cycle ergometer. Subjects then produced the target RPEs on these modalities. Physiological validity of perceptually regulated exercise intensity was determined by comparing VO2 and heart rate between estimation and production trials at the same relative intensity. With one exception, RPE was found to be a valid means of regulating exercise intensity both intra- and intermodally at 50% and 70% VO2max. Perceptual regulation of intramodal treadmill exercise was not valid at 70% VO2max in that both VO2 and heart rate were significantly lower during production than estimation. The present results also indicate that target RPE estimated during a cycle ergometer graded exercise test is more accurate for regulating exercise intensity than when the target RPE is estimated during a treadmill test. The lower accuracy found for treadmill production at the higher exercise intensity may have been caused by the use of a test protocol during the estimation trial that included relatively slow speeds and large inclines. In general, RPE provide a physiologically valid method of regulating exercise intensity.

Adolescent↗
PubMed1992

Abatement of exertional perceptions following dynamic exercise: physiological mediators.

Perceptual and physiological congruity was examined during recovery from high-intensity dynamic exercise. Nine males (24.8 +/- 0.6 yr; VO2max; 52.3 +/- 1.5 ml.kg-1.min-1) undertook in random order four maximal treadmill protocols. Treadmill speed was held constant (5.3 km.h-1) while grade was incremented by 2, 4, 6, or 8% every 3 min for protocols A, B, C, and D, respectively. Ratings of perceived exertion (RPErec; Borg 15-point scale), ventilation (VE), respiratory rate (RR), oxygen uptake (VO2), and heart rate (HR) were measured preexercise and during each min of a 12-min supine postexercise period that immediately followed treadmill testing. Ratings were obtained for the peripheral perceptual signal arising from the legs (RPErec-L), the respiratory-metabolic signal from the chest (RPErec-C), and the overall body signal (RPErec-O). Blood pH was measured preexercise and during min 1, 6, and 12 of recovery. RPErec-L and RPErec-O were lower (P less than 0.05) and blood pH higher (p less than 0.05) following protocol A than D at all recovery time points. RPErec-C, VE, and RR were lower (P less than 0.05) for protocol A than D at all recovery time points. Differences among protocols were not noted for VO2 or HR at any recovery time point. The decay in signal strength for both RPErec-L and RPErec-O following high-intensity exercise reflected the abatement of metabolic acidosis. RPErec-O was influenced by the abatement of pulmonary ventilation during the postexercise period.

Acidosis↗
PubMedDate not supplied

Manual materials handling: the cause of over-exertion injury and illness in industry.

It is reported from various sources that overexertion due to lifting, pushing, pulling, and carrying objects accounts for about 27 percent of all compensable industrial injury and illness in the United States. Resulting strain/sprain injuries account for over 50 percent of workmen's compensation clams in many industries. Almont two-thirds of these involve back pain, with reported compensation and medical payments totaling well over one billion dollars annually in the U.S. An estimated 300,000 plus workers will be affected each year, 5 to 10 percent of whom will have a permanent disability and often will be unemployable. This paper attempts to describe four basic approaches used to study this occupational health problem. In so doing, a concerted effort is made to identifiy the gaps in knowledge which need to be more fully researched. The approaches utilized to understand and control the hazards of manual materials handling are: 1) epidemiological studies of job and worker attributes to identify those that individually and in combination cause musculoskeletal incidents, 2) psychophysical studies to ascertain the volitional tolerance of workers to the stress mitigated by manual materials-handling activities, 3) biomechanical studies of the musculoskeletal system during common exertions required in manual materials-handling activities, and 4) physiological studies of the strain imposed on the cardiovascular system during repeated load-handling activities. The state of knowledge from each of these approaches is summarized briefly, and a case is made that much research is still needed to substantiate the necessary controls to lessen the economic burden and human suffering associated with manual materials-handling acts in industry.

Adolescent↗
PubMed2006

Risk factors for recruit exertional heat illness by gender and training period.

INTRODUCTION: Exertional heat illness (EHI) is a recurrent problem for both male and female recruits during basic military training. A matched case control study investigated the effects of fitness and conditioning on EHI risk among Marine Corps recruits during 12 wk of basic training at Marine Corps Recruit Depot, Parris Island, SC. METHODS: Physical fitness and anthropometric measurements at entrance were acquired for 627 EHI cases that occurred during the period 1988-1996 and for 1802 controls drawn from the same training platoons. Conditional logistic regression was used to estimate EHI risk. RESULTS: Slower physical fitness test run times during processing week strongly predicted risk for subsequent EHI in both male and female recruits. A 9% increase in risk for EHI associated with body mass index (BMI = kg x m(-2); weight/height2) was found in male recruits, while BMI was not associated with risk among female recruits. BMI and initial run time were important predictors for EHI in early training, while in late training the initial BMI was no longer as important a risk factor and improvements in fitness reduced risk. CONCLUSION: Tables of estimated absolute risks categorized by BMI and VO2max are provided as a guide for identifying recruits who are at high risk for developing EHI during training.

Adult↗
PubMed1991

Physiologic parameters and perceived exertion with local muscle fatigue in postpolio subjects.

Fifty postpolio patients, 34 with and 16 without complaints of progressive loss of muscle strength, and 41 control subjects were studied to compare physiologic measures of the fatiguing process and to determine whether there is a significant interaction between the rating of perceived exertion (RPE) and physiologic measures. Statistical analyses were by ANOVA and repeated-measures ANOVA. The RPE was obtained every 20 seconds during an isometric contraction of the quadriceps at 40% of maximal torque; median frequency (Fm) of the power spectrum of the surface electromyographic signal and neuromuscular efficiency (NME) were constantly monitored. The RPE increased similarly (p greater than .05), whereas Fm and NME decreased similarly (p greater than .05) during endurance exercise at 40% of maximal torque in all three groups. A significant (p less than .05) interaction was found between RPE and both Fm and NME. We conclude that physiologic measures of the fatiguing process (Fm and NME) occur in a similar manner in postpolio and control subjects and that there is a significant interaction between subjective RPE and physiologic measures of the fatiguing process.

Electromyography↗
PubMed1991

Liver failure occurring as a component of exertional heatstroke.

An unusual case of an exertional heatstroke in a healthy 25-year-old man is presented. Initially, the patient was deeply comatose and developed severe rhabdomyolysis and massive hepatic necrosis. Subsequently, he received a liver transplant with remarkable improvement in his mental status, although the rhabdomyolysis continued. The patient died 41 days after the transplant due to a complicating infection. Providing that infections can be effectively controlled, liver transplants might be a promising therapeutic alternative for the few patients who survive the initial neurological consequences of this unusual event.

Adult↗
PubMed1991

[Isolated exertion headache and Chiari's malformation].

A 47 year-old woman had been suffering from exertional headache for 2 1/2 years. Neurological examination was normal. X-rays of the skull and cranio-cervical junction and CT were normal. MRI sagittal sections disclosed a Chiari type I malformation. The headache disappeared after occipital craniectomy and atlas laminectomy.

Arnold-Chiari Malformation↗
PubMed1991

[Perceived exertion during simulated static work].

The purpose of this study was to determine the effect of static work on the rating of perceived exertion (RPE). The subject were healthy, relatively fit young adults (16 men). Exercise was performed at 25% MVC both in a commonly-used work posture and in a non-typical working posture (overhead-work). Estimates of effort were recorded using the CR-20-Scale by Borg. A nonparametric analysis was carried out to examine the relationship between the level of static load and RPE. The results show that the level of static load is reflected in the RPE systematically. It is concluded that RPE measurements render possible comparative evaluation of strain by muscular static work demands.

Adult↗
PubMed1990

Exertional intensities and energy requirements of technical mountaineering at moderate altitude.

The purpose of this study was to determine the exertional energy requirements of technical mountaineering at moderate altitude. Six subjects completed maximum graded exercise tests (MGXT) prior to a 7-day ice climbing seminar conducted in the North Cascade Range of the United States. Mean weight, percent body fat, and maximum oxygen uptake (VO2max) were 71.3 (+/- 15.1) kg, 11.7 (+/- 4.2) %, and 53.7 (+/- 5.4) ml.kg-1.min-1 respectively. Heartrates (HR) were recorded and averaged over 5-second to 1-minute intervals during selected mountaineering activities of the ice climbing seminar. Average and peak estimated VO2 (EstVO2) and estimated energy expenditure (EstEE) were calculated from HR utilizing regression equations generated from the MGXT results. Trail hiking with loads averaging 45% of individual body weight required an average EstVO2 of 21.8 (+/- 3.0) ml.kg-1.min-1 and average EstEE of 7.5 (+/- 1.9) kcal.min-1 over a 2.2 hr period. Mean peak EstVO2 was 37.4 (+/- 3.4) ml.kg-1.min-1 and mean peak EstEE was 13.4 (+/- 3.0) kcal.min-1 during this period. Technical ice climbing involving movement up and down a 12 m vertical height for a mean time of 14.3 (+/- 2.6) min required an average EstVO2 and EstEE of 25.7 (+/- 7.6) ml.kg-1.min-1 and 9.5 (+/- 3.4) kcal.min-1 respectively. Peak EstVO2 and EstEE means were 38.4 (+/- 7.7) ml.kg-1.min-1 and 14.6 (+/- 3.5) kcal.min-1. Two subjects were monitored during a 6-hour summit ascent on snow and ice from 1636 m to 3266 m. Means for average EstVO2 and EstEE were 21.6 (+/- 3.3) ml.kg-1.min-1 and 7.2 (+/- 0.8) kcal.min-1 respectively while peak EstVO2 and EstEE means were 38.0 (+/- 6.1) ml.kg-1.min-1 and 13.3 (+/- 1.6) kcal.min-1. The total EstEE was 3096.8 and 2485.4 kcal for these two subjects over the 6-hour ascent. The most experienced climber averaged 0.078 kcal.kg-1.min-1 and the least experienced subject averaged 0.105 kcal.kg-1.min-1 while climbing at identical paces over the same terrain. This indicates a possible experience factor which may increase climbing efficiency.

Adult↗
PubMed1990

Effects of caffeine on the rate of perceived exertion.

The role of caffeine in improving performance in endurance exercises is controversial and its mechanism of action is not well understood. The purpose of the present study was to evaluate the effects of caffeine on the rate of perceived exertion (RPE) by exercising athletes. Six male non-smoking runners, aged 26.8 +/- 4.9 years (mean +/- SD), who had been in training continuously for at least two years before the experiment were studied. Mean maximum oxygen consumption (VO2max) was 61.21 +/- 5.36 ml kg-1 min-1. The subjects were asked to exercise on a bicycle ergometer for 3 min each at 300 and 600 kg m min-1, after which the work load was elevated to 1200 kg m min-1 and they exercised until exhaustion. In order to evaluate the effects of caffeine, the exercise was performed twice following the ingestion of 200 ml decaffeinated coffee with and without caffeine (5 mg/kg body weight). Caffeine had no significant effect on exercise time, pulmonary ventilation, oxygen consumption, carbon dioxide extraction or exchange respiratory ratio, but the RPE was significantly lower (P less than 0.05) at the work load of 1200 kg m min-1 after the ingestion of caffeine for both trials I and II. The present results suggest that metabolic acidosis and glycogen depletion were not the main causes of exhaustion.

Adult↗
PubMed1990

Acute exertional rhabdomyolysis in hypothyroidism: the result of a reversible defect in glycogenolysis?

A 28-year-old man on thyroid hormone replacement following treatment with radioactive iodine for Graves' disease developed an episode of acute exertional rhabdomyolysis. He was found to be hypothyroid and had no rise in serum lactic acid following an ischemic exercise test. With additional thyroid replacement, his ischemic exercise test normalized and his muscle symptoms resolved. This observation suggests that rhabdomyolysis in hypothyroidism may be due to a reversible defect in glycogenolysis and that hypothyroidism should be excluded in patients with rhabdomyolysis and/or myoglobinuria.

Adult↗
PubMed1990

Exertional rhabdomyolysis in two prison inmates.

We have reported two cases of exertional rhabdomyolysis which resolved without serious complication. The denial and exclusion of significant historical information initially made the specific etiology of rhabdomyolysis indeterminate in the first case.

Adult↗