Effects of Propranolol on Several Physiological Responses During Orthostatic and Exercise Stress in Healthy Male Subjects

1971 ◽  
Vol 49 (10) ◽  
pp. 867-872 ◽  
Author(s):  
Michael G. Maksud ◽  
Felix E. Tristani ◽  
Kenneth D. Coutts ◽  
Joseph J. Barboriak ◽  
Lyle H. Hamilton
Keyword(s):  
Heart Rate ◽  
Minute Ventilation ◽  
Young Male ◽  
Work Capacity ◽  
Exercise Stress ◽  
Blood Pressures ◽  
Propranolol Treatment ◽  
Propranolol Administration ◽  
Exercise Endurance ◽  
Male Subjects

The effects of propranolol administration on several responses to orthostatic and exercise stress were examined in 16 healthy young men. Propranolol treatment resulted in a significantly lower heart rate response to orthostatic stress, while systolic and diastolic blood pressures were unaffected by the drug. Propranolol treatment resulted in a significant reduction in heart rate and minute ventilation during bicycle exercise. However, oxygen consumption and mean exercise endurance times were not significantly altered following propranolol treatment. The findings suggest that in healthy young male subjects the cardiac depressant effects of propranolol are compensated for, so that the oxygen uptake and work capacity are not seriously compromised.

Heart rate performance curve during incremental cycle ergometer exercise in healthy young male subjects

1997 ◽  
Vol 29 (6) ◽  
pp. 762-768 ◽  
Author(s):  
PETER HOFMANN ◽  
ROCHUS POKAN ◽  
SERGE P. VON DUVILLARD ◽  
&NA; J. SEIBERT ◽  
ROBERT ZWEIKER ◽  
...  
Keyword(s):  
Heart Rate ◽  
Young Male ◽  
Cycle Ergometer ◽  
Performance Curve ◽  
Rate Performance ◽  
Cycle Ergometer Exercise ◽  
Ergometer Exercise ◽  
Male Subjects

Maximal heart rate during work in older men

1959 ◽  
Vol 14 (4) ◽  
pp. 562-566 ◽  
Author(s):  
Irma Åstrand ◽  
Per-Olof Åstrand ◽  
Kaare Rodahl
Keyword(s):  
Heart Rate ◽  
Ambient Air ◽  
Work Load ◽  
Work Capacity ◽  
Bicycle Ergometer ◽  
Maximal Heart Rate ◽  
Average Maximum ◽  
Work Up ◽  
Aerobic Work Capacity ◽  
Male Subjects

Nine 56–68-year-old male subjects performed muscular work up to maximal loads on a bicycle ergometer while breathing both ambient air and oxygen. Heart rate increased to an average maximum of 163/min. The maximal O2 intake averaged 2.24 l/min. and the blood lactic acid concentration 85 mg/100 ml. In no case was the maximal heart rate higher when breathing O2 than when breathing air. This low maximal heart rate in older people probably limits the capacity for O2 intake. Four subjects were able to work for about 1 hour without any sign of exhaustion on a work load requiring an O2 consumption of about 50% of their maximal aerobic work capacity. Submitted on October 3, 1958

Physiological effects of hydrogen sulfide inhalation during exercise in healthy men

1991 ◽  
Vol 71 (5) ◽  
pp. 1872-1877 ◽  
Author(s):  
Y. Bhambhani ◽  
M. Singh
Keyword(s):  
Hydrogen Sulfide ◽  
Oxygen Uptake ◽  
Maximal Exercise ◽  
Lactate Concentration ◽  
Young Male ◽  
Work Capacity ◽  
Physical Work ◽  
Physical Work Capacity ◽  
Maximal Power Output ◽  
Male Subjects

Occupational exposure to hydrogen sulfide (H2S) is prevalent in a variety of industries. H2S when inhaled 1) is oxidized into a sulfate or a thiosulfate by oxygen bound to hemoglobin and 2) suppresses aerobic metabolism by inhibiting cytochrome oxidase (c and aa3) activity in the electron transport chain. The purpose of this study was to examine the acute effects of oral inhalation of H2S on the physiological responses during graded cycle exercise performed to exhaustion in healthy male subjects. Sixteen volunteers were randomly exposed to 0 (control), 0.5, 2.0, and 5.0 ppm H2S on four separate occasions. Compared with the control values, the results indicated that the heart rate and expired ventilation were unaffected as a result of the H2S exposures during submaximal and maximal exercise. The oxygen uptake had a tendency to increase, whereas carbon dioxide output had a tendency to decrease as a result of the H2S exposures, but only the 5.0 ppm exposure resulted in a significantly higher maximum oxygen uptake. Blood lactate concentrations increased significantly during submaximal and maximal exercise as a result of the 5.0 ppm exposure. Despite these large increases in lactate concentration, the maximal power output of the subjects was not significantly altered as a result of the 5.0 ppm H2S exposure. It was concluded that healthy young male subjects could safely exercise at their maximum metabolic rates while breathing 5.0 ppm H2S without experiencing a significant reduction in their maximum physical work capacity during short-term incremental exercise.

Bicycle Crank Length

1976 ◽  
Vol 20 (18) ◽  
pp. 415-421
Author(s):  
V. John Gross ◽  
Corwin A. Bennett
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Perceived Exertion ◽  
Young Male ◽  
Bicycle Ergometer ◽  
Adult Males ◽  
Heavy Load ◽  
Percentage Points ◽  
Male Subjects ◽  
Crank Length

An experiment was conducted varying bicycle crank length as a ratio of cyclist's crotch height over a range from 0.17 to 0.23. A light and a heavy load were used with ten young male subjects. Heart rate, oxygen consumption and perceived exertion measures were taken during bicycle ergometer pedaling sessions. All measures showed the superiority of a crank length of about 0.20 of crotch height (0.10 of standing height). A change of crank length of three percentage points of crotch height increases energy expenditure by one kcal/minute. The standard crank is too long for 60% of adult males and almost 100% of females. Varied crank lengths or adjustable cranks should be made available.

scholarly journals Analysis of Individual Variations in Autonomic Responses to Urban and Forest Environments

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Hiromitsu Kobayashi ◽  
Chorong Song ◽  
Harumi Ikei ◽  
Takahide Kagawa ◽  
Yoshifumi Miyazaki
Keyword(s):  
Heart Rate ◽  
Urban Areas ◽  
Young Male ◽  
Autonomic Activity ◽  
Mean Values ◽  
Autonomic Responses ◽  
Conventional Analysis ◽  
Individual Variations ◽  
The Difference ◽  
Male Subjects

Autonomic responses to urban and forest environments were studied in 625 young male subjects. The experimental sites were 57 forests and 57 urban areas across Japan. The subjects viewed the landscape (forest or urban environment) for a period of 15 min while sitting on a chair. During this period, heart rate variability (HRV) was monitored continuously. The results were presented as histograms and analyzed with special reference to individual variations. Approximately 80% of the subjects showed an increase in the parasympathetic indicator of HRV (lnHF), whereas the remaining subjects showed a decrease in the parasympathetic activity. Similarly, 64.0% of the subjects exhibited decreases in the sympathetic indicator of HRV (ln[LF/HF]), whereas the remaining subjects showed opposite responses. Analysis of the distribution of HRV indices (lnHF and ln[LF/HF]) demonstrated the effect of forest environments on autonomic activity more specifically than the conventional analysis based on the difference in mean values.

Circulatory and ventilatory effects of exercise in smokers and nonsmokers

1963 ◽  
Vol 18 (2) ◽  
pp. 357-360 ◽  
Author(s):  
Robert B. Chevalier ◽  
John A. Bowers ◽  
Stuart Bondurant ◽  
Joseph C. Ross
Keyword(s):  
Heart Rate ◽  
Maximal Exercise ◽  
Young Male ◽  
Bicycle Ergometer ◽  
Debt Accumulation ◽  
Ventilatory Responses ◽  
Ventilatory Effects ◽  
Ergometer Test ◽  
Male Subjects ◽  
Bicycle Ergometer Test

To evaluate the effects of cigarette smoking on some of the circulatory and ventilatory responses to exercise, a group of young male subjects, 18 smokers and 14 nonsmokers, was studied. Exercise consisted of a standard 5-min bicycle ergometer test that achieved a mean O2 uptake of 1.44 liters/ min in the 5th min of exercise. There was no difference between smokers and nonsmokers in the O2 uptake achieved during subsequent maximal exercise. Pulmonary function studies performed on the two groups revealed normal results for each group. There was an oxygen debt accumulation among smokers that was significantly greater ( P < 0.001) and this debt represented a greater per cent of the total O2 uptake. The heart rate at rest and 3 min after exercise in smokers was significantly faster ( P < 0.02). These differences do not appear to be related to ventilatory factors and may, therefore, be due to either circulatory or metabolic differences in the two groups. Submitted on August 17, 1962

scholarly journals The correlations of glycated hemoglobin and carbohydrate metabolism parameters with heart rate variability in apparently healthy sedentary young male subjects

Redox Biology ◽  
2015 ◽  
Vol 5 ◽  
pp. 301-307 ◽  
Author(s):  
Andriy Cherkas ◽  
Orest Abrahamovych ◽  
Sergii Golota ◽  
Armen Nersesyan ◽  
Christoph Pichler ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Carbohydrate Metabolism ◽  
Glycated Hemoglobin ◽  
Young Male ◽  
Male Subjects ◽  
Apparently Healthy

Comparative physiological responses to exercise stress

1982 ◽  
Vol 52 (4) ◽  
pp. 1077-1083 ◽  
Author(s):  
A. B. Hastings ◽  
F. C. White ◽  
T. M. Sanders ◽  
C. M. Bloor
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Venous Blood ◽  
Work Capacity ◽  
Exhaustive Exercise ◽  
Exercise Stress ◽  
Maximal Heart Rate ◽  
O2 Consumption ◽  
Acid Base Balance ◽  
Acid Base

We determined the effect of exhaustive exercise on the acid-base balance, O2 consumption, and cardiac output in dogs and pigs to examine which species was comparable with humans in its physiological response to exercise. We ran 11 dogs and 11 pigs on a motor-driven treadmill at steady-state (heart rate 75% maximum) and exhaustive (maximum heart rate) exercise levels. Measuring heart rate, cardiac output, and aortic pressure via implanted probes we obtained arterial and venous blood samples before, during, and after exercise to determine hematocrit, blood gas tensions, pH, and lactic acid levels. Dogs had a twofold greater work capacity than the pigs, but the dogs could not run at maximal heart rate as long as the pigs did. Although O2 consumption correlated well with cardiac output and total work in both species, dogs were capable of a greater range of values. The acid-base studies showed that exhaustive exercise in the pigs resulted in a severe metabolic acidosis, whereas this did not occur in dogs. Respiratory alkalosis was noted in dogs. This suggested that the supply of O2 to the working muscles of the pig was insufficient to maintain aerobic metabolism. The pigs' responses to exercise conformed to those found by others in the human, suggesting that the pig is a more appropriate model for some exercise studies.

Ultrastructural Study of Human Testicular Biopsies in Infertility

1976 ◽  
Vol 34 ◽  
pp. 156-157
Author(s):  
Shirley Siew ◽  
Philip Troen ◽  
Howard R. Nankin
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Basement Membrane ◽  
Leydig Cells ◽  
Clinical Evidence ◽  
Young Male ◽  
Germinal Epithelium ◽  
Transmission Electron ◽  
Age Range ◽  
Male Subjects

Testicular biopsies were obtained from six young male subjects (age range 24-33) who complained of infertility and who had clinical evidence of oligospermia. This was confirmed on histological examination which showed a broad spectrum from profound hypospermatogenesis to relatively normal appearing germinal epithelium. Thickening of the tubular walls was noted in half of the cases and slight peritubular fibrosis in one. The Leydig cells were reported as normal or unremarkable.Transmission electron microscopy showed that the thickening of the supporting tissue of the germinal epithelium was caused more by an increase in the thickness of the layers of the lamina propria than of the tubular wall itself. The changes in the basement membrane of the tubular wall consisted mostly of a greater degree of infolding into the tubule and some reduplication which gave rise to a multilayered appearance.

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