Effect of beta1 selective adrenoceptor blockade on physiological response to exercise.

Abstract

SUMMARY The effect of the beta1 selective adrenoceptor blocker, atenolol, on the physiological response to exercise was studied in 12 healthy young men. Oral atenolol (100 mg) and placebo were administered in a randomised double blind crossover fashion an hour and a half before an intermittent multistage cycle ergometer exercise test. At maximal effort oxygen consumption, pulmonary ventilation, carbon dioxide output, and respiratory exchange ratio were not modified by atenolol. In contrast, maximal heart rate and performance time were significantly reduced after atenolol. Nevertheless, because the relation of percentage of maximal oxygen consumption to percentage of maximal heart rate was not changed by atenolol both the absolute and relative oxygen consumption corresponding to 70% and 85%h of the maximal heart rate remained unaltered.These data suggest that recommendations of exercise intensity may be determined on the basis of a calculated percentage of the predetermined maximal heart rate in persons without symptomatic coronary heart disease receiving beta1 selective adrenoceptor blockers.

Reduced ambulatory heart rate response to physical work and complaints of fatigue among hypertensive males treated with beta-blockers

“…Subjects were a group of male employees aged >_45 years containing sufficiently large numbers of treated persons to test the study hypotheses. As expected, beta-blockers were found to lower HR at rest, which is consistent with the known physiological effects of the drugs (Gordon et al, 1985(Gordon et al, , 1987Hossack el al., 1980;Lund-Johansen, 1974).…”

Betabloqueio com atenolol não reduz potência aeróbia nem muda limiares ventilatórios em hipertensos sedentários

“…The beta blockers effect in the VO 2peak is very controversial in the literature [7][8][9] , with some studies presenting decrease [14][15][16][17] and others no alteration [18][19][20] . The main explanations for these discrepancies between studies are the methodological differences, especially concerning the population studied and the type of beta blocker used.…”

Comparison of Continuous and Intermittent Multistage Maximal Exercise Testing During Beta-Adrenoceptor Blockade in Physically Active Men

“…However, despite the now common practice of prescribing endurance conditioning for patients treated with beta-adrenoceptor blocking drugs (8), previous comparisons have been limited to persons not receiving cardioactive medication. This may be of clinical importance to physically active persons without symptomatic coronary artery disease since pharmacologic blockade of beta-adrenoceptors accentuates fatigue during exercise (5) and the potential detrimental effect of an increased fatigue on the cardiorespiratoty response to graded maximal exercise testing is likely to be exaggerated by the use of a continuous as opposed to intermittent exercise protocol in such individuals (7).…”