摘要:

WOLFE, L.A., D.A. CUNNINGHAM, J.E. PAULSETH, and P.A. RECHNITZER. The value of combining noninvasive techniques in exercise testing.Med. Sci. Sports Exercise.Vol. 12, No. 3, pp. 200–204, 1980. A 3-stage cycle ergometer exercise test which combines the noninvasive measurement of systolic time intervals (STI's), stroke volume (SV), mean systolic ejection rate (MSER) and blood pressure was administered to 2 groups of middle-aged men, Group 1 include 15 healthy men. Group 2 consisted of 20 men with coronary artery disease (CAD), confirmed by a proven myocardial infarction. The groups were matched for age, weight and height. Over the range of heart rates (HR's) encountered (70–173 beats min-1) the STI's described an inversely linear relationship with HR. At all exercise HR's, group 2 displayed higher values for total electromechanical systole (QS2), left ventricular ejection time (LEVET) and the pre-ejection period (PEP), and lower values for SV and MSER. Statistical comparison of all variables at a common HR of 110 beats min-1indicated that QS2and MSER best discriminated between the groups. It was concluded that this test is sufficiently sensitive to detect differences in cardiac performance in groups of subjects, but not for the diagnosis of CAD in individual patients.

ISSN:0195-9131    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

CHAFFIN, DON B., MYUN LEE, and ANDRIS FREIVALDS. Muscle strength assessment from EMG analysis.Med. Sci. Sports Exercise.Vol. 12, No. 3, pp. 205–211, 1980. Isometric strength is a useful indicator of a person's capacity to safely perform tasks requiring high physical effort. This paper develops and evaluates a method for the improved assessment of such strength using surface electrode EMG analysis of graded, submaximal exertions. The method is evaluated by having two groups of volunteers each perform repeated isometric elbow flexions while EMG's were obtained from the biceps brachii. Subjects in one group were instructed by a third party to “fake” all exertions at levels between 50% and 75% of that requested by the experimenter. The second group was asked to give full cooperation. The experimenters were “blind” as to which group any one subject belonged until all EMG analyses were complete. The EMG's were evaluated by comparing their rectified amplitudes during a slowly increasing (five second) exertion requirement and a submaximal exertion at a requested 50% MVC level until fatigue, i.e., when the subject no longer could or would retain the requested exertion over a three-second period. The changes in the EMG amplitude during the endurance hold were used to determine the maximum potential EMG and whether the subject was faking or sincere. The changes in the relationship between EMG amplitude and the force of exertion on the progressive exertion requirement along with the estimated maximum EMG allowed the prediction of maximum strength and thus the level at which each subject was exerting. Of the 22 subjects, all 10 fakers and 11 of 12 sincere subjects were correctly identified. A theoretical basis for the method is discussed.

ISSN:0195-9131    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

FRED, HERBERT L. Reflections on a 100-mile run: effects of aspirin therapy.Med. Sci. Sports Exercise.Vol. 12, No. 3, pp. 212–215, 1980. I finished a 100-mile competitive run in hot, humid weather. Because of knee pain, I took therapeutic amounts of aspirin before and throughout the race. Based on empirical evidence, I conclude that aspirin increased my sweat rate, body temperature, and urinary output; inhibited my thirst; abolished my knee pain; and blunted my sense of fatigue. The overall effect was detrimental and predisposed me to heat illness. From the information presented, two potential effects of aspirin have become evident. First, aspirin therapy (approximately 10 or more tablets daily) may be dangerous when combined with physical exertion in the heat. Second, aspirin therapy might reduce the extreme thirst sometimes associated with hyperreninemia. Both hypotheses deserve further study.

ISSN:0195-9131    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

WILMORE, JACK H., PAUL A. VODAK, RICHARD B. PARR, ROBERT N. GIRANDOLA, and JOHN E. BILLING. Further simplification of a method for determination of residual lung volume.Med. Sci. Sports Exercise.Vol. 12, No. 3, pp. 216–218, 1980. This paper describes a modification of the standard oxygen-dilution technique for determining residual lung volume, whereby rapid responding oxygen and carbon dioxide analyzers are used to determine the point of nitrogen equilibration, and a five-liter rebreathing bag is substituted for the standard spirometer. This simplified method reduced the total test time to five min or less for duplicate determinations, and eliminated the need for a nitrogen analyzer and a spirometer. This method was found to be both reliable (r = 0.99) and valid (r = 0.92), with a standard error of prediction of 125 ml, and a mean difference of only eight ml, when compared with the established oxygen-dilution technique on a sample of 76 healthy men and women, 19 to 55 years of age. In a subsample of 13 subjects, residual volume was also determined with the nitrogen washout technique, which correlated r=0.89 and r=0.91 with the established and modified oxygen-dilution techniques respectively. The use of assumed values for the initial and final alveolar concentrations of nitrogen did not appear to significantly influence the final results.

ISSN:0195-9131    

出版商:OVID    

年代:1980

数据来源: OVID

ISSN:0195-9131    

出版商:OVID    

年代:1980

数据来源: OVID

ISSN:0195-9131    

出版商:OVID    

年代:1980

数据来源: OVID

ISSN:0195-9131    

出版商:OVID    

年代:1980

数据来源: OVID