Effect of beta-blockade during bowling competitions.

Seventeen amateur bowlers taking part in local bowling competitions were given either 40 mg of oxprenolol or placebo before the competitions, so that each subject played two competitions on oxprenolol and two on placebo in random order. All the bowlers had a relative tachycardia 15 min before the competition which was abolished by oxprenolol. A similar reduction in the heart rate during and after the compeptition was likewise seen after oxprenolol. The drug caused only minor changes in the systolic blood pressure in comparision with placebo. On the whole, the total scores of placebo and oxprenolol competitions did not differ significantly from each other, nor was there any difference between the scores of the trial competitions and the average results during previous season. However, when the bowlers were divided into subgroups according to the effect exerted by oxprenolol on performance, about one third of the bowlers did benefit from the oxprenolol treatment while 50% had worse results. The bowlers whose bowling performance was improved by oxprenolol exhibited significantly higher heart rates before, during and after the competition as compared with the subgroups not responding beneficially to the active drug. The effect of oxprenolol was most pronounced during the very first series and the harmful effect of the drug was mainly seen in the last series of the competition. One reason for the impairment of the general performance could conceivably be an "overrelaxed" state as indicated by the greater number of misses made by the bowlers when treated with oxprenolol.

RCT Entities:   Population Interventions Outcomes