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 865 records · Page 48Linked to original sources
PubMed1991

Effect of work load and respirator wear on postural stability, heart rate, and perceived exertion.

The effects on postural stability (sway) were investigated for different work loads under conditions of wearing a full facepiece respirator and not wearing any respiratory protection device. Fifteen subjects accomplished light (40 W), moderate (85 W), and heavy (125 W) work loads under the two conditions. Measurements of postural sway were made immediately after each load by using a multicomponent, strain gage-type force platform. Changes in each subject's movement pattern of the center of pressure were quantitated and compared to their initial baseline sway tests. Each subject's heart rate and perceived exertion were also recorded during each condition. A statistically significant effect (p = 0.007) caused by work load was observed for total length of sway with or without a respirator. An interaction approaching statistical significance (p = 0.056) between work load and respirator use was found. This indicated that sway increased more quickly and in a more consistently linear fashion with increasing work load under the respirator condition (p = 0.02) compared to the nonrespirator condition. The results from the respirator condition showed linear increases in postural sway length across the entire range of work loads, but sway length in the nonrespirator condition showed an increase only at 125-W work loads. The greater increase in sway during the postural balance test could be attributable to the increasing work load-induced proprioceptive fatigue effect on the nervous system's ability to process signals from proprioception systems incongruent with body sway. The heart rate was significantly higher during respirator wear (an increase in heart rate averaging 5.62 beats/min).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Perceived exertion is related to muscle activity during leg extension exercise.

This study examined the relationship between ratings of perceived exertion and muscle activity during dynamic leg extension exercise using a resistance exercise specific OMNI-RPE scale. Twenty volunteers (10 males, 10 females, age 22.2 +/- 3.1 yr) performed one set of leg extension exercise at 30%, 60%, and 90% of their one-repetition maximum (1-RM). OMNI-RPE responses were assessed for both the active muscle (OMNI-AM) and the overall body (OMNI-O) following each intensity. Electromyography (EMG) data were collected from the rectus femoris, vastus lateralis, and vastus medialis muscles. A two-factor repeated measures ANOVA showed a significant OMNI-RPE (region) X intensity interaction (p < 0.01). Both OMNI-AM and OMNI-O increased with exercise intensity, and RPE-AM was higher than RPE-O at all intensities. EMG activity increased with exercise intensity in all muscle groups (all p < 0.01). Muscle activity was significantly and positively related to OMNI-RPE in both the active muscle and overall body (all p < 0.01). The OMNI-Res RPE scale may be a promising technique for regulating resistance training intensity.

Adult↗
PubMed2004

Fatal exertional heat stroke: a case series.

BACKGROUND: Exertional heat stroke (EHS) is one of the most serious conditions that occur when excess heat, generated by muscular exercise, exceeds the body's heat-dissipation rate. The consequent elevated body core temperature causes damage to the body's tissues, resulting in a characteristic multiorgan syndrome, which is occasionally fatal. METHODS: We analyzed the fatal EHS cases that occurred in the Israeli Defence Forces during the last decade according to Minard's paradigm for evaluation of EHS predisposing factors, aiming to characterize the common features and unique circumstances leading to fatality. RESULTS: Accumulation of predisposing factors, particularly those concerning training regulations, coupled with inappropriate treatment at site, were found to be strong predictors of a grave prognosis. Analysis of the pathologic findings of the fatal EHS cases on autopsy revealed a possible association between the duration and length of exercise prior to EHS occurrence and the extent of pathologic findings. CONCLUSIONS: Strict adherence to existing training regulations may prevent further heat stroke fatalities.

Adolescent↗
PubMed1994

Perceived exertion and muscle efficiency in Parkinson's disease: L-DOPA effects.

Weakness, easy fatiguing, and lack of endurance are commonly perceived by patients with Parkinson's disease (PD). Although the slowed motor repertoire in PD may underlie these experiences, other abnormalities in skeletal muscle utilization also may be involved. We investigated whether an index of metabolic efficiency during a continuous exercise task, the latency until anaerobic threshold (AT), is altered by L-DOPA (LD). While pedalling a bicycle ergometer against a uniform workload, subjects were monitored for expired O2 and CO2. As compared to an unmedicated state, LD treatment delayed AT by a mean (+/-SE) of 5.67 +/- 0.89 to 6.62 +/- 1.23 min (p < 0.05), paired t test). Subjects did not differ in their perceived exertion upon reaching AT. With relief of parkinsonism by LD, the efficiency of energy utilization is also increased in exercised skeletal muscle.

Adult↗
PubMed2004

Is there a link between malignant hyperthermia and exertional heat illness?

Exertional heat illness (EHI) and malignant hyperthermia (MH) are two potentially lethal conditions. It has been suggested that a subset of MH susceptible persons may be predisposed to EHI. We examine the current understanding of these disorders and explore evidence of a relationship. Screening for the muscle type I ryanodine receptor gene should help clarify the relationship between MH and EHI.

Acidosis↗
PubMedDate not supplied

Influence of nicardipine on the blood pressure at rest and on the pressor responses to cold, isometric exertion, and dynamic exercise in hypertensive patients.

The dose-response effects of a new slow-calcium-channel blocker, nicardipine, on the resting blood pressure and on the pressor responses induced by skin cold, isometric exertion, and dynamic exercise were examined in a single-blind placebo-controlled study in six male patients with stable uncomplicated essential hypertension. Nicardipine was administered orally in doses of 5 mg, 10 mg, 20 mg, and 20 mg each given three times daily consecutively for 1 week. At the end of each dose period the effects on blood pressure and heart rate at rest and during the three pressor stimuli were measured. There was a significant dose-related reduction in the resting diastolic blood pressure without change in pulse pressure, accompanied by an increase in heart rate. No postural effects on blood pressure were observed. There was a small reduction in the pressor response to hand cold, which was statistically significant at the higher doses. There was no attenuation of the increases in pressure and heart rate induced by handgrip contraction or submaximal treadmill walking at any dose of nicardipine. These results are compatible with direct relaxing effect of the drug on the smooth muscle of the arteriolar resistance vessels without substantial impairment of the sympathetic influences responsible for postural control of the systemic blood pressure or those involved in the pressor responses to the three stimuli tested.

Adult↗
PubMed1991

A double-blind, placebo-controlled, parallel dose-response study of amlodipine in stable exertional angina pectoris.

A placebo-controlled, double-blind, dose-response study of amlodipine (1.25, 2.5, 5, and 10 mg once daily) was carried out in 136 patients with stable exertional angina pectoris. Improvements in total exercise tolerance, time to onset of angina during exercise, ST-segment deviation at maximum common load, frequency of angina attacks, and nitroglycerin consumption were greater following amlodipine than placebo. The maximum improvement in exercise parameters occurred with the highest dose of amlodipine. All doses produced significant reductions in angina attack frequency and the rate of nitroglycerin consumption. Amlodipine was well tolerated and no patients were withdrawn due to adverse events or laboratory abnormalities.

Adult↗
PubMed1991

A 6-week double-blind comparison of amlodipine and placebo in patients with stable exertional angina pectoris receiving concomitant beta-blocker therapy.

This study was a multicenter, double-blind comparison of the antianginal efficacy and safety of amlodipine and placebo as adjunctive therapy with constant recommended maintenance doses of beta-blockers. Patients with stable exertional angina pectoris were randomized to placebo or amlodipine at a starting dose of 5 mg once daily. The amlodipine dose was adjusted to 10 mg daily after 2 weeks if angina attacks were not abolished. Antianginal efficacy was assessed throughout the study with angina diaries, investigators' and patients' global evaluations, and with bicycle exercise tests during a placebo run-in period (baseline) and after 2 and 6 weeks of double-blind treatment. On baseline-final analysis, the exercise time to angina onset increased by 13% with amlodipine compared to 6% with placebo (p < 0.05). The total exercise time increased by 11% on amlodipine compared with 2% on placebo, though this difference did not reach statistical significance. Angina attack frequency and nitroglycerin consumption were both reduced by adding amlodipine to beta-blocker treatment. Amlodipine in combination with beta-blocker therapy was well tolerated, with a low incidence of side effects and laboratory test abnormalities. The study showed clearly that addition of amlodipine to beta-blocker therapy in patients with stable angina pectoris was well tolerated and gave improved antianginal efficacy.

Adolescent↗
PubMed1991

An 8-week double-blind study of amlodipine and diltiazem in patients with stable exertional angina pectoris.

A multicenter, double-blind study was performed to compare the antianginal efficacy and safety of the new dihydropyridine calcium antagonist amlodipine with the benzothiazepine calcium antagonist diltiazem in patients with stable exertional angina pectoris. Following a 2-week placebo run-in period, 39 patients were randomized to receive amlodipine (2.5-10 mg once daily) and 41 patients to receive diltiazem (60-120 mg three times daily) in an 8-week double-blind treatment phase. The study used standardized bicycle exercise testing as a primary efficacy assessment. Patients also recorded angina frequency and nitroglycerin (NTG) tablet consumption/ week. Treatment with amlodipine and diltiazem resulted in an improvement in total exercise time, time to angina and total work, mean ST-segment deviation at maximum common load, median number of angina attacks/week, and NTG tablet consumption/week. The incidence and severity of possibly treatment-related side effects and laboratory test abnormalities were comparable for both drugs. The most frequently reported side effects were dizziness, headache, peripheral edema, and nausea. Two patients withdrew from diltiazem treatment due to pruritus in one case and severe headache and moderate dyspnea in the other. No amlodipine-treated patients withdrew due to side effects. In conclusion, this study demonstrated that the antianginal efficacy and tolerability of amlodipine is equivalent to diltiazem, but amlodipine has the advantage of once-daily dosing.

Adult↗
PubMed1997

Effects of oral and intravenous rehydration on ratings of perceived exertion and thirst.

The purpose of this investigation was to compare the effects of oral and intravenous saline rehydration on differentiated ratings of perceived exertion (RPE) and thirst. Eight men underwent three randomly assigned rehydration treatments following a 2- to 4-h exercise-induced dehydration bout to reduce body weight by 4%. Treatments included 0.45% saline infusion (i.v.), 0.45% saline oral ingestion (ORAL), and no fluid (NF). Following rehydration and rest (2 h total), subjects walked at 50% VO2max for 90 min at 36 degrees C (EX). Central RPE during ORAL was lower (P < 0.05) than i.v. and NF throughout EX. Local RPE during NF was higher (P < 0.05) than i.v. and ORAL at minutes 20 and 40 of EX and overall RPE during NF was higher (P < 0.05) than ORAL at minutes 20 and 40 of EX. Significant correlations were found between overall RPE and mean skin temperature for i.v. (r = 0.72) and NF (r = 0.75), and between overall RPE and thirst ratings for i.v. (r = 0.70). Thirst ratings were not different among trials at postdehydration. Following rehydration, thirst was higher (P < 0.05) during NF than i.v. and ORAL and lower (P < 0.05) during ORAL than i.v. at all subsequent time points. Results suggest that oral rehydration is likely to elicit lower RPE and thirst ratings compared with intravenous rehydration.

Adult↗
PubMed2000

Perceived exertion with glucose ingestion in adolescent males with IDDM.

PURPOSE: The rating of perceived exertion (RPE) is an indicator of exercise effort in adolescents that may be influenced by certain pediatric conditions. The purpose of this study was to determine the influence of insulin-dependent diabetes mellitus (IDDM) and glucose intake on RPE. METHODS: Eight male adolescents with IDDM and eight healthy controls of similar age, weight, and VO2peak cycled for 60 min at 60%VO2peak on two occasions spaced 1-4 wk apart. During a control trial (CT), subjects drank water, and in a glucose trial (GT), glucose at a rate of approximately 1.5 g x kg(-1) x h(-1). Heart rate, ventilation, and RPE (Borg 6-20 scale) were assessed at 5, 25, 35, and 55 min and blood glucose and lactate levels before and at 30 and 60 min. RESULTS: RPE in both trials was 15-25% higher in IDDM versus healthy subjects (F = 8.83; df = 1,14; eta-squared = 0.39; P = 0.01). In CT, it increased from 10.6 +/- 0.4 at 5 min to 15.2 +/- 0.6 at 55 min in IDDM and from 9.3 +/- 0.9 at 5 min to 13.0 +/- 0.8 at 55 min in healthy adolescents. In GT, RPE increased similarly to CT in the IDDM group but was 1-2 points lower in the healthy group. Blood glucose levels were 4.8 +/- 1.8 mmol x L(-1) and 1.8 +/- 0.4 mmol x L(-1) higher by the end of exercise in GT than in CT for the IDDM and healthy groups, respectively. There were no differences in heart rate, ventilation, or lactate levels between the groups or trials. CONCLUSIONS: For exercise performed at a similar moderate intensity, RPE in IDDM is higher by 2-3 points than in controls. Compared with water, glucose intake is associated with lower RPE in healthy, but not in IDDM, adolescents.

Adolescent↗
PubMed2000

A review of chronic exertional compartment syndrome in the lower leg.

Chronic exertional compartment syndrome (CECS) in the lower leg has been described as early as 1956. This review describes the five relevant anatomical compartments and the important clinical features on presentation used in diagnosis. Compartment pressure testing using various types of catheter is useful as a confirmatory investigation. Although the pathophysiology of this condition is poorly understood, current hypotheses are discussed. Surgical treatment is usually definitive and techniques for decompression of the five compartments are presented with comparison to available conservative treatments.

Anterior Compartment Syndrome↗
PubMed2001

Rating of perceived exertion during high-intensity treadmill running.

PURPOSE: The purpose of this investigation was 1) to evaluate the time course of the rating of perceived exertion (RPE; 6-20 Borg scale) during short-term, high-intensity, constant-load running (ST); and 2) to determine the reproducibility of RPE during ST. METHODS: Fifteen well-trained males (VO2max = 58.0 +/- 4.6 mL x kg(-1) x min(-1), mean +/- SD) performed treadmill running (i.e., between 3 and 4 m.s-1 at 10.5% incline) to volitional exhaustion (Tlim) at an exercise intensity equivalent to 125% VO2max. A total of four RPE measurements were taken during each test, one every 30 s during the first 120 s of the exercise. The tests were repeated at the same time of day on three occasions within a 3-wk period. RESULTS: Tlim for the three tests was 197.6 +/- 34.8 s. RPE was linearly related with exercise time (mean +/- SD for the three tests: RPE at 30 s = 10.8 +/- 2.2; RPE at 60 s = 12.6 +/- 1.8; RPE at 90 s = 14.5 +/- 1.7; RPE at 120 s = 16.0 +/- 1.9; RPE = 9.06 + (0.06 x time (s)); r = 0.71, SEE = 2.0, P < 0.01). Repeated ANOVA revealed no systematic bias between the three tests for RPE, and other measures of reliability were also favorable. These included intraclass correlation coefficients ranging from 0.78 to 0.87 and sample coefficients of variation of between 4.4% and 6.0%. The 95% limits of agreement ranged between 0.0 +/- 2.3 and 0.0 +/- 2.5. CONCLUSION: ST RPE displays a positive linear response during the first 2 min. The measurement of ST RPE appears to be reliable and could thus add a new dimension to ST investigations.

Adult↗
PubMed2002

Self-regulated cycling using the Children's OMNI Scale of Perceived Exertion.

PURPOSE: An estimation and production paradigm was used to determine whether clinically normal 8- to 12-yr-old female (N = 18) and male (N = 18) children could (a) self-regulate intermittent cycle ergometer exercise using a prescribed target rating of perceived exertion (RPE), (b) discriminate between target RPEs, and (c) produce intermittent target RPEs in both an ascending and descending sequence. METHODS: Overall body RPE was assessed with the Children's OMNI Scale (0-10). Subjects underwent (a) one orientation trial, (b) one estimation (E) trial, and (c) two production (P) trials. During E, RPE was estimated each minute of a progressive cycle ergometer test. During the 3-min intermittent P trials, subjects titrated cycle brake force to produce either an RPE sequence of 2 and 6 (ascending) or 6 and 2 (descending). The P trials simulated short, intermittent exercise typical of children's play. RESULTS: Oxygen uptake (VO2) did not differ between E and P at a target RPE of 2 (0.63 versus 0.66 L x min(-1)) and 6 (1.27 vs 1.21 L x min(-1)). Heart rate (HR) did not differ between E and P at a target RPE of 2 (104.1 vs 102.6 beats.min-1) and 6 (153.7 vs 154.5 beats x min(-1)). Both VO2 and HR were higher (P < 0.01) at a target RPE-6 than -2. Responses were not affected by gender or production sequence. CONCLUSION: Young female and male children were able to use the OMNI Scale to self-regulate short-duration intermittent cycle exercise intensity.

Child↗
PubMed2002

Effect of carbohydrate ingestion on ratings of perceived exertion during a marathon.

PURPOSE: The purpose of this study was to investigate the effects of carbohydrate substrate availability on ratings of perceived exertion (RPE) and hormonal regulation during a competitive marathon. METHODS: A randomized, double-blind study design was used in which subjects ran the marathon, and every 3.2 km, RPE and heart rate were measured. The marathoners were randomly assigned to receive carbohydrate (C) (N = 48) or placebo (P) (N = 50) beverages at a rate of 1 L x h(-1) during the race. RESULTS: Heart rate (%(HRMAX) ) was lower in P (82.0% +/- 0.6) than C (84.2% +/- 0.6) (P < 0.01), especially during the final 10 km: (78.7% +/- 1.0) and (84.5% +/- 0.7), respectively (P < 0.001). RPE was not significantly different between P and C throughout the marathon (P = 0.08) or during the final 10 km: (16.8 +/- 0.3) and (16.1 +/- 0.3), respectively (P = 0.06). Postrace plasma glucose (P < 0.001), insulin (P < 0.001), and lactate (P < 0.05) levels were significantly lower in P than C, and postrace cortisol (P < 0.05) significantly higher in P compared with C. CONCLUSIONS: Marathoners ingesting carbohydrate compared with placebo beverages were able to run at a higher intensity while reporting a nonsignificant difference in RPEs during a competitive race.

Adult↗
PubMed2002

Chronic exertional compartment syndrome: muscle changes with isometric exercise.

UNLABELLED: Chronic exertional compartment syndrome (CECS) is a well-documented cause of lower leg pain in active individuals. The pathophysiology is unclear, although it is generally believed to be associated with increased intramuscular pressure, but there is very little information about muscle function in relation to the onset of pain. PURPOSE: To investigate strength, fatigue, and recovery of the anterior tibial muscles in CECS patients and healthy subjects during an isometric exercise protocol. METHODS: Twenty patients and 22 control subjects (mean age 27.6 yr and 33.0 yr, respectively) performed a 20-min isometric exercise protocol consisting of intermittent maximal voluntary contractions (MVC). Central fatigue was evaluated by comparing changes in electrically stimulated (2 s at 50 Hz) and voluntary contraction force before and during the exercise, and then throughout 10 min of recovery. Muscle size was measured by ultrasonography. Pain and cardiovascular parameters were also examined. RESULTS: The absolute MVC forces were similar, but MVC:body mass of the patients was lower (P < 0.05) as was the ratio of MVC to muscle cross-sectional area (P < 0.01). The extent of central and peripheral fatigue was similar in the two groups. The patients reported significantly higher levels of pain during exercise (P < 0.05 at 4 min) and after the first minute of recovery (P < 0.001). An 8% increase in muscle size after exercise was observed for both groups. There were no differences in the cardiovascular responses of the two groups. CONCLUSIONS: CECS patients were somewhat weaker than normal but fatigued at a similar rate during isometric exercise. Patients reported higher pain than controls despite comparable changes in muscle size, suggesting that abnormally tight fascia are not the main cause of CECS symptoms.

Adult↗
PubMed2002

Reliability and validity of the Borg and OMNI rating of perceived exertion scales in adolescent girls.

PURPOSE: To examine the reliability and validity of the Borg and OMNI rating of perceived exertion (RPE) scales in adolescent girls during treadmill exercise. METHODS: Adolescent girls (N = 57, age = 15.3+/-1.5 yr) were randomly assigned to use an RPE scale (Borg or OMNI) during one of three treadmill submaximal exercise conditions (walking, walking uphill, or jogging). After RPE assessment, exercise intensity was increased until participants achieved volitional exhaustion (O2max). Expired respiratory gases and heart rate (HR) were measured continuously during exercise. Reliability of the RPE scales was assessed using ANOVA (intraclass) and Spearman-Brown prophecy formula (single trial) measures. Validity estimates were calculated using Pearson Product Moment correlations, with % HRmax and % O2max as criterion measures. RESULTS: Intraclass and single-trial reliability estimates were higher for the OMNI (r(xx) = 0.95 and r(kk) = 0.91, respectively) compared with the Borg (r(xx) = 0.78 and r(kk) = 0.64, respectively) RPE scale. Validity estimates were also higher for the OMNI scale compared with the Borg scale. Validity coefficients (r(xy)) for %HRmax and %O2max comparisons were 0.86 and 0.89, respectively, for the OMNI, compared with 0.66 and 0.70, respectively, for the Borg. CONCLUSION: The OMNI cycle pictorial scale was found to be reliable and valid for use with adolescent girls. It also appears to be more reliable and valid than the Borg scale for use in this population during treadmill exercise.

Adolescent↗
PubMed1988

Ovarian cancer manifested as exertional hypotension due to obstruction of the inferior vena cava.

We have reported a case of inferior vena cava obstruction caused by recurrent ovarian carcinoma. This case is noteworthy first because it shows that physical findings in inferior vena cava obstruction may be minimal. Secondly, we believe ours is the first reported case of exertional hypotension caused by obstruction of the inferior vena cava. Finally, ovarian cancer has rarely been reported as a cause of inferior vena cava obstruction.

Cystadenocarcinoma↗