Abstract des Autors

The aim of this study was to investigate the validity of heart rate (fc) and ratings of perceived exertion (RPE) as indices of exercise intensity in a group of children while swimming. Six healthy male swimmers, aged 10-12, swam tethered using the breast-stroke in a flume. The resistance started at 1.0 kg and increased in 1.0 kg steps up to the point of their exhaustion. The subjects swam for 5 min during each period, with a rest of 10-20 min until they had returned to their resting fc level. The last exercise intensity was with the maximal mass the subjects could support for 2 min. The last min of oxygen consumption (V02) and 30 s of fc were measured during each exercise period. The subjects gave their RPE assessment at the end of exercise. The individual relationships between fc and V02, and V02max were linear with a high correlation r=0.962-0.996 and r=0.962-0.996 and r=0.996, respectively. It was concluded that fc was valid as an index of the exercise intensity of children while swimming. Compared to the results found in adults using a similar protocol, the childrens fc were 8.3-26.9 beats/min higher than those of the adults at the given V02max. The present study showed two different patterns in the relationship between V02 and RPE in individuals. In 2 subjects the RPE increased linearly with V02, in the other 4 subjects the increase was discontinuous. If fc and RPE were to be applied to the setting and evaluation of exercise intensity during swimming, it would seem that fc would be a more useful guide than RPE.