Cardiovascular response to cycle exercise during and after pregnancy

1989 ◽  
Vol 66 (1) ◽  
pp. 336-341 ◽  
Author(s):  
S. P. Sady ◽  
M. W. Carpenter ◽  
P. D. Thompson ◽  
M. A. Sady ◽  
B. Haydon ◽  
...  
Keyword(s):  
Heart Rate ◽  
Maximal Exercise ◽  
Cardiovascular Response ◽  
Work Load ◽  
Cycle Ergometry ◽  
Maximal Heart Rate ◽  
O2 Uptake ◽  
Cycle Exercise ◽  
Vascular Beds ◽  
Response To Exercise

Our purpose was to determine if pregnancy alters the cardiovascular response to exercise. Thirty-nine women [29 +/- 4 (SD) yr], performed submaximal and maximal exercise cycle ergometry during pregnancy (antepartum, AP, 26 +/- 3 wk of gestation) and postpartum (PP, 8 +/- 2 wk). Neither maximal O2 uptake (VO2max) nor maximal heart rate (HR) was different AP and PP (VO2 = 1.91 +/- 0.32 and 1.83 +/- 0.31 l/min; HR = 182 +/- 8 and 184 +/- 7 beats/min, P greater than 0.05 for both). Cardiac output (Q, acetylene rebreathing technique) averaged 2.2 to 2.8 l/min higher AP (P less than 0.01) at rest and at each exercise work load. Increases in both HR and stroke volume (SV) contributed to the elevated Q at the lower exercise work loads, whereas an increased SV was primarily responsible for the higher Q at higher levels. The slope of the Q vs. VO2 relationship was not different AP and PP (6.15 +/- 1.32 and 6.18 +/- 1.34 l/min Q/l/min VO2, P greater than 0.05). In contrast, the arteriovenous O2 difference (a-vO2 difference) was lower at each exercise work load AP, suggesting that the higher Q AP was distributed to nonexercising vascular beds. We conclude that Q is greater and a-vO2 difference is less at all levels of exercise in pregnant subjects than in the same women postpartum but that the coupling of the increase in Q to the increase in systemic O2 demand (VO2) is not different.(ABSTRACT TRUNCATED AT 250 WORDS)

Physical work capacity of college women

1965 ◽  
Vol 20 (2) ◽  
pp. 263-266 ◽  
Author(s):  
Ernest D. Michael ◽  
Steven M. Horvath
Keyword(s):  
Heart Rate ◽  
Body Weight ◽  
Exercise Tolerance ◽  
Maximal Exercise ◽  
Work Load ◽  
Work Capacity ◽  
Physical Work ◽  
Physical Work Capacity ◽  
Maximal Heart Rate ◽  
Cardiorespiratory Function

Maximal exercise tolerance tests were given to 30 female subjects 17-22 years old. The test consisted of exercising 1 min at a work load of 300 kpm/min and increasing the work load 150 kpm/min each minute until the subject could no longer exercise. The maximal heart rate level averaged 184 beat/min with a range between 170 and 202 beat/min. The average maximal Vo2 was 1.78 liter/min or 29.8 ml/kg per min. The submaximal ventilatory measurements were similar for all subjects while the heart rate levels at the submaximal work loads differentiated the subjects when grouped according to maximal work-load capacities. Prediction of maximal work capacity could not be made for individuals from any single submaximal measurement. There was .56 correlation between body weight and maximal work capacity with only a .32 relationship between maximal Vo2 and Vo2 per kilogram body weight. exercise tolerance of women; cardiorespiratory function of women during exercise; submaximal cardiorespiratory response; maximal cardiorespiratory measurements of women; response to maximal exercise; prediction of exercise tolerance Submitted on May 5, 1964

Effects of airflow and work load on cardiovascular drift and skin blood flow

1984 ◽  
Vol 56 (5) ◽  
pp. 1411-1417 ◽  
Author(s):  
J. D. Shaffrath ◽  
W. C. Adams
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Skin Blood Flow ◽  
Prolonged Exercise ◽  
Work Load ◽  
Progressive Increase ◽  
Cycle Ergometry ◽  
O2 Uptake ◽  
Mean Values ◽  
Cardiovascular Drift

Cardiovascular drift (CVD) can be defined as a progressive increase in heart rate (HR), decreases in stroke volume (SV) and mean arterial pressure (MAP), and a maintained cardiac output (Q) during prolonged exercise. To test the hypothesis that the magnitude of CVD would be related to changes in skin blood flow ( SkBF ), eight healthy, moderately trained males performed 70-min bouts of cycle ergometry in a 2 X 2 assortment of airflows (less than 0.2 and 4.3 m X s-1) and relative work loads (43.4% and 62.2% maximal O2 uptake). Ambient temperature and relative humidity were controlled to mean values of 24.2 +/- 0.8 degrees C and 39.5 +/- 2.4%, respectively. Q, HR, MAP, SkBF , skin and rectal temperatures, and pulmonary gas exchange were measured at 10-min intervals during exercise. Between the 10th and 70th min during exercise at the higher work load with negligible airflow, HR and SkBF increased by 21.6 beats X min-1 and 14.0 ml X 100 ml-1 X min-1, respectively, while SV and MAP decreased by 16.4 ml and 11.3 mmHg. The same work load in the presence of 4.3 m X s-1 airflow resulted in nonsignificant changes of 7.6 beats X min-1, 4.0 ml X (100 ml-1 X min)-1, -2.7 ml, and -1.7 mmHg for HR, SkBF , SV, and MAP. Since nonsignificant changes in HR, SkBF , SV, and MAP were observed at the lower work load in both airflow conditions, the results emphasize that CVD occurs only in conditions which combine high metabolic and thermal circulatory demands.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of beta-adrenergic blockade on O2 uptake during submaximal and maximal exercise

1983 ◽  
Vol 54 (4) ◽  
pp. 901-905 ◽  
Author(s):  
P. A. Tesch ◽  
P. Kaiser
Keyword(s):  
Heart Rate ◽  
Maximal Exercise ◽  
Pulmonary Ventilation ◽  
Submaximal Exercise ◽  
Beta Blockade ◽  
Adrenergic Blockade ◽  
Maximal Heart Rate ◽  
O2 Consumption ◽  
O2 Uptake ◽  
Beta Adrenergic

Changes in cardiorespiratory variables and perceived rate of exertion (RPE) were studied in 13 trained men performing cycling exercise before and after beta-adrenergic blockade. Propranolol (Inderal, 80 mg) was administered orally 2 h prior to standardized maximal and submaximal exercises. Muscle biopsies were obtained from vastus lateralis at rest for subsequent histochemical analyses of muscle fiber type distribution and capillary supply. During submaximal exercise O2 consumption decreased from 2.76 to 2.59 l . min-1 following blockade (P less than 0.01), whereas heart rate decreased from 157 to 113 beats . min-1 (P less than 0.001). Maximal O2 uptake was lowered from 3.79 to 3.26 l . min-1 (P less than 0.001) and maximal heart rate was reduced from 192 to 142 beats . min-1 (P less than 0.001) as a result of the blockade. Pulmonary ventilation was unaltered in both exercise conditions. “Local” RPE was higher (P less than 0.001) than “central” RPE after beta-blockade in both submaximal and maximal exercise. During normal condition this difference did not appear. Changes in both local and central RPE during submaximal exercise were positively correlated to changes in O2 uptake. Individual variations in the metabolic profile of the exercising muscle had no influence on beta-blockade-induced changes in O2 uptake. It is concluded that blockade of beta-adrenergic receptors reduces O2 consumption during submaximal (approximately 73% maximal O2 uptake) and maximal exercise in habitually trained men.

Intersubject variability in cardiac output-O2 uptake relation of men during exercise

1986 ◽  
Vol 61 (6) ◽  
pp. 2168-2174 ◽  
Author(s):  
I. Yamaguchi ◽  
E. Komatsu ◽  
K. Miyazawa
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Cardiovascular Response ◽  
Regression Line ◽  
Maximum Level ◽  
Intersubject Variability ◽  
O2 Uptake ◽  
Vascular Conductance ◽  
Individual Variations ◽  
Response To Exercise

Intersubject variability in the relation between cardiac output (Q) and O2 uptake (VO2) was examined during supine cycling up to the maximum level in 40 normal untrained men age 27 +/- 4 (SD) yr. In individual subjects, Q increased linearly against VO2 in the submaximum exercise range. The SD of Q on VO2 was so small (0.47 +/- 0.25 l/min) that Q could be given by a linear function of VO2 as Q = K(VO2 - VO2 r) + Qr, where K, VO2 r, and Qr are the slope of the regression line, the resting VO2, and resting Q, respectively. K varied widely among the subjects studied, ranging from 5.5 to 10.3 and was independent of both physical characteristics and Qr, which ranged from 3.7 to 8.3 l/min. However, K correlated significantly with changes in heart rate, stroke volume, mean arterial pressure, and systemic vascular conductance. From these results, we concluded that the intersubject variability in the Q-VO2 relation was caused independently by individual variations in resting hemodynamics and in cardiovascular response to exercise.

scholarly journals The Chronic Effects of Narghile Use on Males’ Cardiovascular Response During Exercise: A Systematic Review

2021 ◽  
Vol 15 (2) ◽  
pp. 155798832199770
Author(s):  
Faten Chaieb ◽  
Helmi Ben Saad
Keyword(s):  
Systematic Review ◽  
Heart Rate ◽  
Cardiovascular Response ◽  
Recovery Period ◽  
Cardiopulmonary Exercise Test ◽  
Negative Effects ◽  
Chronic Effects ◽  
Blood Pressures ◽  
Response To Exercise ◽  
Harmful Effects

Narghile use has regained popularity throughout the world. Public opinion misjudges its chronic harmful effects on health, especially on the cardiovascular system. This systematic review aimed to evaluate the chronic effects of narghile use on cardiovascular response during exercise. It followed the preferred reporting items for systematic reviews guidelines. Original articles from PubMed and Scopus published until January 31, 2020, written in English, and tackling the chronic effects of narghile use on human cardiovascular response during exercise were considered. Five studies met the inclusion criteria. Only males were included in these studies. They were published between 2014 and 2017 by teams from Tunisia ( n = 4) and Jordan ( n = 1). One study applied the 6-min walk test, and four studies opted for the cardiopulmonary exercise test. Narghile use was associated with reduced submaximal (e.g., lower 6-min walk distance) and maximal aerobic capacities (e.g., lower maximal oxygen uptake) with abnormal cardiovascular status at rest (e.g., increase in heart rate and blood pressures), at the end of the exercise (e.g., lower heart rate, tendency to chronotropic insufficiency) and during the recovery period (e.g., lower recovery index). To conclude, chronic narghile use has negative effects on cardiovascular response to exercise with reduced submaximal and maximal exercise capacities.

scholarly journals Autonomic cardiovascular response during and after a graded exercise test in concussed athletes and healthy controls

2021 ◽  
Vol 5 ◽  
pp. 205970022110448
Author(s):  
Alessandra Ventura ◽  
Fausto Romano ◽  
Mario Bizzini ◽  
Antonella Palla ◽  
Nina Feddermann
Keyword(s):  
Heart Rate ◽  
Cardiovascular System ◽  
Exercise Test ◽  
Cardiovascular Response ◽  
Heart Rate Recovery ◽  
Exercise Intolerance ◽  
Maximal Heart Rate ◽  
Healthy Controls ◽  
Graded Exercise Test ◽  
Graded Exercise

Objective Dysfunction of the autonomic cardiovascular system after a concussion is known to cause exercise intolerance due to symptoms exacerbation. The aim of this study was to compare athletes with symptoms of a sport-related concussion and healthy controls with regard to their heart rate during a graded exercise test and their heart rate recovery during the 5 min cool-down after the graded exercise test. Methods Sport-related concussion patients ( N = 61; 31% female) and controls ( N = 16; 50% female) participated in a graded exercise test on a cycle ergometer followed by 5 min active cool-down. Based on the results of graded exercise tests they were divided into four groups: (1) patients who reached the symptom threshold and had to stop the graded exercise test (symptom threshold; N = 39; 33.3% female), (2) patients with symptoms who finished the graded exercise test (S; N = 16; 25% female), (3) patients without symptoms (NS; N = 6; 33.3% female), (4) controls ( N = 16; 50% female). Main outcome measures Heart rate, severity of headache and dizziness during graded exercise test, heart rate recovery (median (heart rate recoveries/maximal heart rate) ± median absolute deviation (MAD)) 30, 60 and 300 s after the start of cool-down. Results Heart rate recovery at 30 s was significantly slower in symptom (0.95 ± 0.01) compared to all other groups ( p < 0.002; symptom threshold: 0.92 ± 0.02, NS: 0.91 ± 0.02, controls: 0.93 ± 0.02). Heart rate recovery at 60 s was significantly slower in symptom (0.90 ± 0.02) compared to the symptom threshold and controls ( p < 0.041; 0.86 ± 0.03, 0.85 ± 0.04). Heart rate recovery at 300 s was significantly slower in symptom threshold (0.72 ± 0.05) compared to controls ( p = 0.003; 0.66 ± 0.02). Conclusions Heart rate measurements in athletes with symptoms of sport-related concussion should be continued during cool-down after the graded exercise test, as dysfunction of the autonomic cardiovascular system might manifest also during cool-down.

scholarly journals Stress Echocardiography in Hyperthyroidism

1999 ◽  
Vol 84 (7) ◽  
pp. 2308-2313 ◽  
Author(s):  
George J. Kahaly ◽  
Stephan Wagner ◽  
Jana Nieswandt ◽  
Susanne Mohr-Kahaly ◽  
Thomas J. Ryan
Keyword(s):  
Heart Rate ◽  
Ejection Fraction ◽  
Stroke Volume ◽  
Stress Echocardiography ◽  
Maximal Exercise ◽  
Stroke Volume Index ◽  
Work Load ◽  
Left Ventricular ◽  
Volume Index ◽  
Systolic Volume

Exertion symptoms occur frequently in subjects with hyperthyroidism. Using stress echocardiography, exercise capacity and global left ventricular function can be assessed noninvasively. To evaluate stress-induced changes in cardiovascular function, 42 patients with untreated thyrotoxicosis were examined using exercise echocardiography. Studies were performed during hyperthyroidism, after treatment with propranolol, and after restoration of euthyroidism. Twenty- two healthy subjects served as controls. Ergometry was performed with patients in a semisupine position using a continuous ramp protocol starting at 20 watts/min. In contrast to control and euthyroidism, the change in end-systolic volume index from rest to maximal exercise was lower in hyperthyroidism. At rest, the stroke volume index, ejection fraction, and cardiac index were significantly increased in hyperthyroidism, but exhibited a blunted response to exercise, which normalized after restoration of euthyroidism. Propranolol treatment also led to a significant increase of delta (Δ) stroke volume index. Maximal work load and Δ heart rate were markedly lower in hyper- vs. euthyroidism. Compared to the control value, systemic vascular resistance was lowered by 36% in hyperthyroidism at rest, but no further decline was noted at maximal exercise. The Δ stroke volume index, Δ ejection fraction, Δ heart rate, and maximal work load were significantly reduced in severe hyperthyroidism. Negative correlations between free T3 and diastolic blood pressure, maximal work load, Δ heart rate, and Δ ejection fraction were noted. Thus, in hyperthyroidism, stress echocardiography revealed impaired chronotropic, contractile, and vasodilatatory cardiovascular reserves, which were reversible when euthyroidism was restored.

Fibrinolytic and hemostatic changes during and after maximal exercise in males

1976 ◽  
Vol 40 (3) ◽  
pp. 287-292 ◽  
Author(s):  
G. L. Davis ◽  
C. F. Abildgaard ◽  
E. M. Bernauer ◽  
M. Britton
Keyword(s):  
Heart Rate ◽  
Factor Viii ◽  
Fibrinolytic Activity ◽  
Work Load ◽  
Bicycle Ergometer ◽  
Maximal Heart Rate ◽  
Relative Level ◽  
Maximum Exercise ◽  
Activity Factor ◽  
Male Subjects

To evaluate changes in fibrinolytic activity, factor VIII and other hematological variables during and after a progressive step increment in work load, 10 healthy male subjects (22–27 yr of age) were exercised to exhaustion on an electromagnetic bicycle ergometer. Blood samples were drawn serially throughout the experiment. Little change in fibrinolytic activity was observed before 70–80% maximum heart rate (MHR) was achieved. Major changes occurred after 80% MHR. Peak values coincided with maximum exercise. In contrast major changes in factor VIII were observed between 95 and 100% MHR with peak values occurring 5–10 min postexercise. An increase in white blood cell count, platelet count, and retention was observed at maximum exercise. One individual failed to demonstrate an increase in either fibrinolytic or factor VIII activity. Relating the data to either the percent maximal oxygen uptake or percent maximal heart rate demonstrates the importance of the exercise protocol and exerting all subjects to the same relative level of physiological work.

Measurement of human capacity for aerobic muscular work

1960 ◽  
Vol 15 (6) ◽  
pp. 1001-1006 ◽  
Author(s):  
Charles E. Billings ◽  
Joseph F. Tomashefski ◽  
Earl T. Carter ◽  
William F. Ashe
Keyword(s):  
Heart Rate ◽  
Cardiovascular Response ◽  
Constant Speed ◽  
Strong Positive Correlation ◽  
Scoring Method ◽  
End Point ◽  
Precise Measure ◽  
Temporal Measurement ◽  
Response To Exercise ◽  
Work Done

In an effort to define a simple, precise measure of cardiovascular response to exercise, a test devised by Bruno Balke was studied. The test involves walking at constant speed on a treadmill, the slope of which is periodically increased, while heart rate is measured accurately each minute. Balke had noted that physiologic alterations indicative of impending exhaustion occurred at or near the time the heart rate reached 180/min.; he used the time at which the rate was attained as an end point. Our studies suggested that a single temporal measurement was insufficiently sensitive as an estimate of cardiovascular response to the procedure. Another scoring method was derived, involving the integration of heart rates with respect to time. A strong positive correlation was found between the described score and the work done during each of 133 test runs. Additionally, evidence was obtained which suggests that it may not be necessary to force subjects to an end point near exhaustion in order to estimate their ability to tolerate exercise of this type. Submitted on March 14, 1960

Effects of high-intensity cycle exercise on sympathoadrenal-medullary response patterns

1991 ◽  
Vol 70 (1) ◽  
pp. 8-14 ◽  
Author(s):  
W. J. Kraemer ◽  
J. F. Patton ◽  
H. G. Knuttgen ◽  
C. J. Hannan ◽  
T. Kettler ◽  
...  
Keyword(s):  
High Intensity ◽  
Maximal Exercise ◽  
Cycle Ergometer ◽  
Plasma Norepinephrine ◽  
Response Patterns ◽  
O2 Uptake ◽  
Cycle Exercise ◽  
Before And After ◽  
The Mean ◽  
The Individual

Plasma proenkephalin peptide F immunoreactivity and catecholamines were examined on separate days in nine healthy males before and after maximal exercise to exhaustion at four intensities [36, 55, 73, and 100% of maximal leg power (MLP)] by use of a computerized cycle ergometer. The mean duration of 36, 55, 73, and 100% MLP was 3.31, 0.781, 0.270, and 0.1 min, respectively. All intensities were greater than those eliciting peak O2 uptake for the individual subjects. Blood samples were obtained before, immediately after exercise, and 5 and 15 min after exercise. Significant (P less than 0.05) increases in plasma peptide F immunoreactivity (i.e., from mean resting value of 0.18 to 0.43 pmol/ml) were observed immediately after exercise at 36% MLP. Significant increases in plasma epinephrine were observed immediately after exercise at 36% MLP (i.e., from mean resting value of 2.22 to 3.11 pmol/ml) and 55% MLP (i.e., from mean resting value of 1.67 to 2.98 pmol/ml) and 15 min after exercise at 100% MLP (i.e., from mean resting value of 1.92 to 3.88 pmol/ml). Significant increases for plasma norepinephrine were observed immediately after exercise (36, 55, 73, and 100% MLP), 5 min after exercise (36, 55, and 73% MLP), and 15 min after exercise (36% MLP). Increases in whole blood lactate were observed at all points after exercise for 36, 55, and 73% MLP and 5 min after exercise for 100% MLP. These data show that brief high-intensity exercise results in differential response patterns of catecholamines and proenkephalin peptide F immunoreactivity.

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