PubMed HealthSearch

SEARCH · PubMed Health

Results for “Exercise”

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

The significance of abnormal systolic blood pressure response during supine ergometer exercise and postexercise in ischemic heart disease, studied by exercise radionuclide ventriculography.

The prognostic value of abnormal postexercise systolic blood pressure (BP) response has not been investigated. Therefore, the significance of abnormal BP response during exercise and postexercise was examined in 169 patients with ischemic heart disease subjected to supine ergometer exercise gated equilibrium radionuclide ventriculography, coronary arteriography, and follow up averaging 3.6 years. Abnormal BP response during exercise (exertional "hypotension") was defined as 1) a failure of BP to rise by at least 11 mmHg or 2) an initial rise in BP but subsequent fall by more than 10 mmHg during exercise. Abnormal BP response during postexercise (postexercise "hypertension") was defined as an increase of more than 10 mmHg above the peak exercise BP. Of 169 patients, 51 (30%) had an abnormal BP response. Four types of BP response were identified: exertional "hypotension" (group 1a, n = 11), postexercise "hypertension" (group 1b, n = 30), exertional "hypotension" with postexercise "hypertension" (group 1c, n = 10) and normal BP response (group 2, n = 118). Both average exercise duration and peak heart rate were significantly lower in groups 1a, 1b and 1c than in group 2. The severity of exercise ST-segment depression was greater in groups 1b and 1c than in group 2. However, there was no significant difference in the severity of exercise ST-segment depression between group 1a and group 2. A decline in ejection fraction occurred more frequently in groups 1b and 1c than in group 2. Patients in groups 1a, 1b and 1c had more extensive coronary artery disease (CAD) than did patients in group 2. Medically treated patients with an abnormal BP response (groups 1a, 1b and 1c) had a poorer prognosis than did those with a normal BP response (group 2). These findings suggest that an abnormal BP response during supine exercise is infrequent, but is usually associated with impaired exercise tolerance and severe CAD. An abnormal postexercise BP response is also infrequent, but is more closely associated with evidence of myocardial ischemia and global left ventricular dysfunction than exertional "hypotension". In conclusion, postexercise "hypertension" has the same value as exertional "hypotension" as a predictor of poor prognosis.

Angina Pectoris

Exercise thallium-201 tomographic scintigraphy in the diagnosis of coronary artery disease: emphasis on the effect of exercise level.

Exercise thallium-201 imaging using single-photon emission computed tomography (SPECT) was evaluated in 154 patients with angiographically documented coronary artery disease (CAD) and in 25 normal subjects. Of the 154 patients with CAD, 134 (87%) had abnormal thallium images. By contrast, only 77 (50%) patients had ischemic ST-segment depression (p < 0.001). Among 25 normal subjects, 20 had normal exercise SPECT images. The specificity of exercise SPECT imaging (80% or 20/25) in excluding patients with CAD was not significantly higher than that of exercise electrocardiography (76% or 19/25). For the detection of individual vessel involvement by analysis of territories of perfusion abnormalities, the sensitivity and specificity of exercise SPECT were 72% and 96% for the left anterior descending, 78% and 85% for the right coronary, and 47% and 98% for the left circumflex artery. Ninety (group 1) of the 154 patients with CAD achieved adequate exercise end points (ischemic ST-segment depression or > 85% of maximal predicted heart rate) and 64 (group 2) did not. Exercise SPECT showed significantly more perfusion abnormalities in group 1 than in group 2 (96% vs 75%, p < 0.001). We conclude that: (1) exercise SPECT thallium imaging is more sensitive than exercise electrocardiography for detecting patients with CAD; (2) the sensitivity of the test is affected by the level of exercise; and (3) it is valuable in the identification of individual vessel involvement.

Coronary Disease

Accuracy of RPE from graded exercise to establish exercise training intensity.

The purpose of this investigation was to examine the accuracy of an exercise intensity prescription based upon perceptual responses obtained during a graded exercise test. Fifteen physically active men completed a graded exercise test (GXT) on a motor driven treadmill. Heart rate (HR), oxygen uptake (VO2), and RPE were measured each minute. An RPE intensity prescription was calculated as 75% of heart rate reserve from the GXT heart rate and RPE data. A minimum of 48 h later the subjects completed 10 min of exercise (EXT) on a level treadmill at the prescribed RPE. The subjects set the treadmill speed to elicit an exercise intensity equal to the prescribed perception of effort. There were significant mean differences (P < 0.05) in heart rate between the GXT (161.8 +/- 1.3) and EXT (154.9 +/- 4.5). However, by minute 6 the subjects were within four beats.min-1 of the target heart rate. There were no significant differences (P > 0.05) between GXT and EXT for VO2 (36.1 +/- 5.2, 33.1 +/- 6.4) and VE (64.1 +/- 10.8, 58.4 +/- 13.5) respectively. The present investigation demonstrates that a subject's perceptual response to a GXT can be used to accurately prescribe exercise intensity during level treadmill running. The intensity selected was within a typical range used for exercise prescription. The advantage of RPE as a method of exercise prescription is that an individual does not need to stop during exercise and measure a heart rate, but can make pace adjustments while exercising based solely upon the perception of effort.

Adult

[Exercise-induced ST segment shift in vasospastic angina with special reference to comparisons between treadmill and bicycle ergometer exercise testings].

To assess the difference between cardiovascular responses to treadmill exercise (TM) and those to bicycle ergometer exercise (EM) in provoking coronary spasm, we compared the ST segment shifts (elevation or depression) during TM and EM in 67 patients with vasospastic angina. Coronary artery spasm was demonstrated on angiography. Both TM and EM were performed on the same day during a medication-free period. For both tests, multistage, symptom-limited exercise protocols were used; EM in the morning and TM in the afternoon. The results obtained were as follows: 1. Rate-pressure products at peak exercise during TM and EM were similar. Systolic blood pressure levels at peak exercise were higher during EM than during TM (p < 0.01). The patients' heart rates at peak exercise were higher during TM than during EM (p < 0.01). Diastolic blood pressure levels at peak exercise were higher during EM than during TM (p < 0.05). 2. Exercise-induced ST elevation occurred more frequently with TM than with EM (19% vs 9%, p < 0.05). 3. Exercise-induced ST depression was provided in 27 patients during TM and in 13 during EM (40% vs 19%, p < 0.01). Among 45 patients without significant lesions, ST depression occurred in 19 during TM, but in only 7 during EM (42% vs 16%, p < 0.01). In conclusion, coronary spasm seemed to occur more frequently with TM than with EM. The mechanism causing such difference remains to be elucidated, however, we speculate that the difference between TM and EM as to enhanced autonomous nervous system activity and coronary perfusion exercise may be related to the difference in the incidence of coronary spasm.

Aged

Detecting asymptomatic coronary artery disease using routine exercise testing and exercise thallium scintigraphy in patients with atherosclerotic vascular disease.

ECG-monitored exercise testing has been proposed as a relatively inexpensive and effective means of screening for asymptomatic coronary artery disease in patients presenting for peripheral vascular surgery. Despite the fact that exercise thallium scintigraphy is also dependent on the patient's ability to exercise, using this test in conjunction with ECG-monitored exercise testing may enhance sensitivity and specificity of non-invasive evaluation. Thirty-two patients were subjected to ECG-monitored exercise testing, exercise thallium scintigraphy and coronary angiography. The sensitivity of ECG-monitored exercise testing for detecting coronary artery disease was calculated at 81.8% and the specificity at 87.5%, while the figures for exercise thallium scintigraphy were 73.1% and 33.3% respectively. Using these two methods in combination yielded a predictive accuracy of 90.6%. The only advantage of exercise thallium scintigraphy over exercise ECG appears to be in patients in whom the latter test could not be interpreted or was non-diagnostic.

Adult

Gas exchange, metabolite status and excess post-exercise oxygen consumption after repetitive bouts of exhaustive exercise in juvenile rainbow trout.

Juvenile rainbow trout (approximately 6 g) were exercised to exhaustion in two 5 min bouts given 6 h apart. Resting levels of whole-body lactate and glycogen were restored prior to the second bout. The rate of O2 consumption increased about threefold 5 min after each bout of exercise, while recovery time decreased from 4 h after the first bout to 2-3 h after the second. The excess post-exercise oxygen consumption, i.e. 'oxygen debt', was significantly reduced by 40% after the second exercise bout, despite almost identical rates of lactate clearance and glycogen resynthesis. The rates of CO2 and ammonia excretion increased sixfold and threefold, and recovery times decreased from 4-6 h to 3 h and from 3 h to 1.5 h, respectively. After the first bout, whole-body lactate levels peaked at 5 min post-exercise at about 8.5 times pre-exercise levels. After the second bout, lactate levels peaked at 0 min post-exercise and fell more rapidly during recovery. Whole-body glycogen levels decreased by 70% and 80% and ATP levels decreased by 75% and 65% after the first and second bouts, respectively, while glucose levels increased about 1.5-fold immediately after both bouts. Creatine phosphate levels decreased by 70% and 80% after the first and second bouts, respectively. After 6 h of recovery, creatine phosphate levels were higher after the second bout than after the first. These findings suggest that exhaustive exercise may cause a 'non-specific' increase in metabolic rate not directly related to the processing of metabolites, which is reduced upon a subsequent exercise bout. This is in contrast with the classical 'oxygen debt hypothesis', which states that the oxygen debt and lactate clearance are linked. Furthermore, it appears that two sequential exercise bouts are sufficient to induce a 'training effect', i.e. improved rates of metabolic recovery.

Adenosine Triphosphate

Effects of anticipation, prior-exercise, and breathing frequency to ventilatory response during step exercise: a preliminary study.

We examined the effects of anticipation, prior-exercise, and restricted breathing frequency on the ventilatory transient response to bicycle step exercise (75 W, 4 min, 50 rpm), i.e., 1) whether the increase of work rate was anticipated by the subject or not, 2) whether the exercise was preceded by light exercise (25 W), or rest, and 3) whether the exercise entrained the breathing frequency (f: 12.5/min, or 25/min) or not (voluntary). The corresponding step-on exercise was randomly performed at least two to five times by one adult male subject. As a result, a) the initial rapid ventilatory component, phase 1, was not observed when initiated from light exercise, whereas the overshot phase 1 was observed from rest in anticipation and voluntary breathing frequency condition due to the rapid increase of tidal volume; b) compared with the anticipation condition, the phase 1 response of VE in the non-anticipation condition was slower with prior-rest, and not with prior-light exercise; and c) the restriction of the breathing frequency for entraining the exercise rhythm did not affect the initial rapid response, but decreased the fluctuation of VE in the steady state, compared to the condition of voluntary breathing frequency.

Adult

Joint exercises in elderly persons with symptomatic osteoarthritis of the hip or knee. Performance patterns, medical support patterns, and the relationship between exercising and medical care.

A total of 110 community-living elderly persons with chronic hip and/or knee pain, all of whom met American College of Rheumatology classification criteria for osteoarthritis (OA), were interviewed to obtain information about their performance of therapeutic joint exercises and exercise-related medical care. Although exercises are considered standard treatment for OA and 96% of subjects had seen a physician for the problem, fewer than half had received medical advice to exercise and very few had received thorough exercise-related teaching and monitoring. Arthritis specialists provided significantly more support for exercising than primary care physicians. Forty percent of the total sample and 63% of those advised by a physician to exercise were making some attempt to do so; however, only 10% were exercising in a manner that might be expected to achieve maximum therapeutic benefit. Supportive medical care was highly related to frequency of exercising.

Aged

Exercise echocardiography after stabilization of unstable angina: correlation with exercise thallium-201 single photon emission computed tomography.

The diagnostic usefulness of predischarge exercise echocardiography in 35 patients with unstable angina who responded to medical therapy was correlated with exercise thallium-201 single photon emission computed tomography (TI-SPECT) performed, on the average, three days after the exercise echocardiography. None of the patients had myocardial infarction prior to hospitalization or before TI-SPECT and none had left bundle-branch block on their rest electrocardiogram (ECG). Exercise echocardiography was positive in 21 patients and TI-SPECT in 24. The results of the two techniques were concordant in 28 of 35 patients (agreement = 80%, k = 0.57 +/- 0.14, p less than 0.001). Wall-by-wall comparison of the distribution of exercise-induced wall motion abnormalities with reversible thallium defects showed complete or partial correlation in all of 19 patients in whom both the tests were positive. A positive exercise ECG and positive exercise echocardiography identified 11 of 11 patients with angiographically verified significant coronary artery disease (CAD) and 11 of 12 patients (92%) with positive TI-SPECT. Thus, exercise echocardiography is a valuable addition to routine predischarge exercise test in the noninvasive diagnosis of myocardial ischemia and shows a good correlation with TI-SPECT in detecting and localizing ischemia in patients with unstable angina stabilized on medical therapy.

Angina, Unstable

Normalization of upright exercise hemodynamics and improved exercise capacity one year after orthotopic cardiac transplantation.

The mechanisms of improved functional capacity over the first year after cardiac transplantation are not well studied. To assess the contribution of cardiac changes to this improvement, the serial evolution of upright rest and exercise hemodynamics during graded upright bicycle exercise was studied in 17 patients at 3 and 12 months after heart transplantation. Heart rate responsiveness, reflected by rapid heart rate acceleration on sitting and rapid deceleration after exercise, developed in the first year. Pulmonary capillary wedge pressure was lower at 1 year, both at rest and at peak exercise (10 +/- 3 vs 13 +/- 5 mm Hg at rest supine and 14 +/- 6 vs 18 +/- 8 mm Hg at peak exercise, p less than 0.05). Similarly, right atrial pressures were also significantly lower at 1 year (4 +/- 2 vs 6 +/- 3 mm Hg at rest supine and 6 +/- 5 vs 11 +/- 5 mm Hg at peak exercise, p less than 0.05). Cardiac index at peak exercise was greater at 12 months (6.4 +/- 1.3 vs 5.8 +/- 0.8 liters/min/m2, p less than 0.05), mediated primarily by higher exercise heart rate (135 +/- 16 vs 125 +/- 12 beats/min, p less than 0.05). In the first year after heart transplantation, improved rest and exercise hemodynamics and heart rate responsiveness contribute significantly to the improved functional capacity observed in these patients.

Adult

Body image and weight preoccupation: a comparison between exercising and non-exercising women.

Relationships were examined among certain personality characteristics and variables which assess weight, diet, and appearance concerns for two groups of women--those who were avid exercisers (n = 86) and those who exercised only occasionally or not at all (n = 72). Multiple regression analyses indicated that emotional reactivity (measured by the N scale of the Eysenck Personality Inventory) was strongly related to weight preoccupation (measured by three subscales of the Eating Disorder Inventory) in both groups. Body Mass Index (BMI), but not a measure of subjective body shape, also predicted weight preoccupation for the non-exercisers while the opposite relationship was found for exercisers. In this group, subjective body shape and not BMI influenced weight preoccupation. It was also found that greater body dissatisfaction was related to poorer emotional well-being in the exercise group, and these women reported, to a significantly greater degree than non-exercisers, that their physical appearance was important to their self-esteem. It is possible that an excessive preoccupation with diet and body shape leads some women to take up a vigorous exercise program. However, the absence of differences in weight preoccupation between the groups argues against this. A possibility that has seldom been considered in the literature is that dedication to regular exercise fosters a heightened degree of body narcissism and a distorted impression of one's body size. A focus of attention in an exercise program on the relationship between body size and maximal performance may, in susceptible individuals, increase the likelihood of developing an obsessive attitude toward weight control.

Adult

Distance between homes and exercise facilities related to frequency of exercise among San Diego residents.

Although personal determinants of exercise behavior have been studied extensively, few investigators have examined the influence of the physical environment on exercise habits. A random sample of 2,053 residents of San Diego, CA, were surveyed regarding exercise habits and other variables. A total of 385 exercise facilities in San Diego were classified into categories of either free or pay. After the addresses of respondents and facilities were located on a grid-map and coded, the density of exercise facilities around each respondent's home address was computed. Subjects who reported engaging in three or more exercise sessions per week reported a statistically greater density of pay facilities near their homes than did those who reported no exercise sessions, after controlling for age, education, and income. The finding suggests an association between proximity of exercise facilities and frequency of exercise.

Adult

Effects of exercise and exercise conditioning on blood platelet function.

The effects of exercise and exercise conditioning on blood platelet function were investigated in six healthy individuals who had not engaged in regular exercise for at least 1 yr prior to the study. The subjects (three men and three women) had a mean age of 28 (range 23-32) and participated in a supervised program of treadmill exercise. Subjects exercised for 20 min, three times weekly, for 12 wk at 70-80% of estimated maximum heart rate. Samples for platelet counts, platelet aggregation, and plasma beta-thromboglobulin (beta-TG) were obtained prior to training and after 6 and 12 wk of training. All subjects responded with an increase in aerobic capacity during training. Resting mean systolic and diastolic blood pressures decreased after training (P less than 0.05). Platelet counts increased after exercise, and the increment in week 12 exceeded that in the 1st wk by 57%. Platelet aggregation studies in platelet rich plasma (PRP) showed an increase in slope after exercise (week 1, P less than 0.05) which decreased with training (week 1 vs week 12, P less than 0.01). Aggregation studies utilizing impedance aggregometry in diluted native whole blood showed an acceleration of both spontaneous aggregation (P less than 0.01 weeks 6 and 12) and aggregation using epinephrine as an agonist (P less than 0.05) following exercise. Plasma beta-TG levels did not increase significantly after exercise; however, resting concentrations of beta-TG decreased with training (P less than 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Dopa in plasma increases during acute exercise and after exercise training.

Plasma dihydroxyphenylalanine (dopa) has been shown to originate in sympathetic neurons, and it has been suggested that plasma level reflects activity of tyrosine hydroxylase, the rate-limiting enzyme in the synthesis of catecholamines. In this study, we measured the effects of acute exercise and exercise training on the levels of dopa and catecholamines in the plasma of healthy, older individuals. Venous blood was drawn from 19 men, from 52 to 75 years of age, at rest, at a standard submaximal work load, at peak exercise, and 3 minutes after exercise on a cycle ergometer. Ten of 12 men then completed 12 to 16 weeks of supervised training, and seven continued normal activity. All 17 men were then retested. The seven control subjects subsequently underwent exercise training as above and were retested again. Levels of dopa and catecholamines in plasma samples were measured by high-performance liquid chromatography with electrochemical detection. Dopa levels at rest were considerably higher than free dopamine, epinephrine, and norepinephrine. During short-term exercise, levels of dopa and catecholamines increased. The absolute increase in dopa was greater than the increase in epinephrine or dopamine but was not greater than that in norepinephrine. After the training period, basal dopa levels increased significantly and correlated with the increase in peak oxygen uptake. There was no change in basal conjugated norepinephrine or dopamine levels with exercise or training, but the level of conjugated epinephrine decreased slightly. No changes occurred in levels of dopa or catecholamines in the untrained group. Free dopamine, norepinephrine, and epinephrine levels at peak exercise were increased after exercise training.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Specimen Collection

Effects of humid air breathing during arm or treadmill exercise on exercise-induced bronchoconstriction and refractoriness.

Although it has been reported that inhibitory prostaglandins may be a causal factor in exercise refractoriness, it is still unclear whether exercise-induced bronchoconstriction (EIB) and/or other specific "exercise factors" are necessary to trigger their release and render a subject refractory to subsequent exercise. The purpose of this study was to determine whether non-EIB-producing exercise with the legs or arms could produce refractoriness to a standard treadmill challenge. Eight asthmatic subjects with EIB completed three sessions consisting of two exercise challenges separated by a 30-min rest. In all sessions, the second challenge was done on a treadmill while breathing dry air. Conditions for Challenge 1 were the following: Session A = treadmill, dry air; Session B = treadmill, humid air; Session C = arm cranking, humid air. All three conditions produced a significant degree of refractoriness. There was a tendency for the percent protection index to be greater for Session A; however, no significant differences were found among the three sessions. Therefore, it can be concluded that although both exercise and bronchoconstriction may play a role in producing the refractory period, neither severe bronchoconstriction nor intense exercise with the same muscle groups are required to produce refractoriness.

Adult

Real and pseudo late asthmatic reactions after submaximal exercise challenge in patients with bronchial asthma. A new definition for late asthmatic responses after exercise challenge.

The late asthmatic reaction after exercise challenge remains a controversial issue. In this study, 21 patients recorded peak expiratory flow rate (PEFR) on two control days without performing exercise. There was no difference between both control days when PEFR at 1 h was compared with baseline PEFR and when PEFR at 4 to 13 hours was compared with baseline PEFR. After analyzing variation coefficients of baseline PEFR on a control day and exercise day, PEFR was not allowed to differ more than 15.3 percent in the same patient when comparing exercise day and control day for the late fall in PEFR in the study. In 17 of 81 patients, a late asthmatic reaction after exercise challenge was present when PEFR fall was greater than or equal to 20 percent compared with baseline PEFR value. In eight of the 17 patients, a real late asthmatic reaction to exercise challenge was present with a PEFR fall greater than or equal to 20 percent on at least three successive time points and who had a PEFR fall greater than or equal to 20 percent compared with corresponding clocktime on a control day. The late asthmatic reaction to exercise challenge is characterized not as a nonspecific epiphenomenon, but as a fall in PEFR of greater than or equal to 20 percent compared with baseline PEFR value and with corresponding clocktime on a control day on at least three successive time points. Graphic illustration of airway responses following exercises may facilitate the detection of a late asthmatic response.

Adult