Journal article
Attenuation of exercise conditioning by low dose beta-adrenergic receptor blockade
Journal of the American College of Cardiology, Vol.2(3), pp.551-556
09/1983
DOI: 10.1016/S0735-1097(83)80284-8
PMID: 6135725
Abstract
Because it has been shown that high doses of propranolol (40 to 80 mg orally, four times daily) markedly attenuate cardiovascular response to exercise training in healthy subjects, the effects of lower doses of this nonselective beta-adrenergic receptor antagonist on the conditioning response were investigated. Twelve normal men underwent maximal treadmill testing before and after a 6 week intensive exercise program. After an initial test, six men were randomized in a paired fashion to receive low dose propranolol and the others received no drug. The average propranolol dose ± standard error was 22 ± 4 mg four times daily, and the average decrease in maximal heart rate due to propranolol was 32 ± 4 beats/ min. Both groups trained at comparable intensities. At the end of the training period, propranolol was stopped and testing was repeated so that the effect of beta-receptor blockade was no longer present but the training effects still persisted. Maximal oxygen consumption increased in control subjects from 47.5 ± 1.1 to 51.4 ± 0.4 ml/kg per min (p < 0.05) but was unchanged in those receiving propranolol (47.2 ± 1.9 versus 47.4 ± 1.5). Exercise duration increased in both groups but the increment was greater in the control group (+ 2.4 versus + 1.1 min, p < 0.05).
It is concluded that low level beta-receptor blockade attenuates cardiovascular conditioning in normal subjects in exercise training programs. High levels of sympathetic stimulation during training appear to be important, if not essential, to the conditioning process.
Details
- Title: Subtitle
- Attenuation of exercise conditioning by low dose beta-adrenergic receptor blockade
- Creators
- Randall C. Marsh - University of Colorado HealthWilliam R. Hiatt - University of Colorado HealthH.L. Brammell - University of Colorado HealthLawrence D. Horwitz - University of Colorado Health
- Resource Type
- Journal article
- Publication Details
- Journal of the American College of Cardiology, Vol.2(3), pp.551-556
- DOI
- 10.1016/S0735-1097(83)80284-8
- PMID
- 6135725
- NLM abbreviation
- J Am Coll Cardiol
- ISSN
- 0735-1097
- eISSN
- 1558-3597
- Publisher
- Elsevier Inc
- Language
- English
- Date published
- 09/1983
- Academic Unit
- Cardiovascular Medicine; Internal Medicine
- Record Identifier
- 9984656534902771
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