| Abstrakt: |
Altogether 25 healthy untrained children aged 9 to 12 years were examined. There were 11 boys and 14 girls. The following parameters were measured at rest and during bicycle ergometry: the heart rate, oxygen consumption, pulmonary ventilation, metabolic units, the ratio of oxygen consumption increment, oxygen pulse, stroke and cardiac indices, index of the Q-Z interval and work fitness. The ECG was recorded as well. During exercise, adequate reaction of the cardiorespiratory system was characterized by linear growth of the heart rate, cardiac index and oxygen consumption together with a proportional shortening of the Q-Z interval. At all levels of exercise the girls manifested more pronounced chronotropic stimulation, leading to the attainment of the submaximal heart rate (1.5 Watt/kg). On chronotropic delay overtension of inotropic function was demonstrable in children exposed to high loads, which was accompanied by restriction of the cardiac index growth. |
