[Increase of heart rate and determination of W170 as a measure of physical working capacity in children 5 to 14 years of age (author's transl)].

1. Exercise testing with stepwise increasing workload was performed in 257 healthy children (134 boys, 123 girls) on a bicycle ergometer, which was independent of variations in pedal speed within a certain range. The procedure of exercise was adapted to the children as far as possible. 2. Nomograms and standard values for heart rate during exercise and for physical working capacity at a heart rate of 170/min (W170) were established. The increase of heart rate (from 1.0 to 2.5 Watt/kg) was well correlated to the age, length, body weight and body surface. If heart rate, respectively W170 are related to workload per kg body weight, results are dependent on sex, but not on age. 3. By means of the new standard values a rough evaluation of cardiorespiratory condition is possible, if the heart rate is measured at moderate exercise during steady state. A more precise assessment of the cardio-respiratory fitness is granted by the W170. By this method physical working capacity can be determined in children with heart diseases in a relative simple manner. 4. Normally in stepwise increasing loads the exercise takes 6 minutes per workload. If this time is reduced, an underestimation of the expected heart rate, respectively an overestimation of W170 is observed, which depends on the extent of the shortening of exercise.