Abstract

The changes in heart rate under various work loads on the bicycle ergometer and equivalent swimming speeds were investigated. Twenty-three male preadoles-cent competitive swimmers, the mean age of 13.8 +- 0.83 years, the mean body weight of 57.2 +- 8.47 kg and the mean height of 169.09 +- 7.7 cm, were tested.Each subject exercised for six minutes under the work loads of 1,5, 2,0and 2,5 Skg body weight, while each swam for four minutes at 50, 75, 90 of the maximal swimming speed, and 400 m at the maximal swimming speed, crawl style. The heart rate increased linearly with the increase of work load both during bicycling and swimming. Statistically significant correlation between the swimming and bicycling heart rate was obtained for all work loads togeth- er, while no correlation was found for each separate equivalent work load. Workperformed for a heart beat during bicycle exercise increased with the increase of work load from 1,5 to 2,5 Wkg, and it also increased from 50 to 75 of the maximal swimming speed. A positive correlation between the work performed per heart beat during the bicycle and swimming exercises was obtained for the heaviest and the lightest equivalent work loads. According tothis, the efficiency of the cardiovascular system during the bicycle and swimming exertions is similar. Verf.-Referat