Background. Children treated for acute lymphoblastic leukemia (ALL) with anthracycline antibiotic agents must be followed up for the danger of late cardiotoxic effects of the treatment. Another threat represents the consequence of the protective upbringing and inactive lifestyle. The aim of present study was to assess the exercise cardiorespiratory indexes and anthropometric variables in previously treated children without clinical, ECG and echocardiographic signs of cardiotoxicity, who had been motivated to physical activity. Methods and Results. 29 children (12.3±2.7 years old) previously treated for ALL with anthracyclines were examined. The cumulative dosis of anthracyclines was 224±39.4 mg/m2. The treatment was finished before 4.8±2.1 years and after this period no signs of the late cardiotoxicity were detectable. Both children and their parents were encouraged to the regular physical activity of submaximal intensity. 29 age-and sex-matched control subjects were healthy children, never limited in their activities, but without special physical training. As soon as the basic anthropometric data had been verified, both groups completed a progressive exercise test with the assessment of submaximal and maximal spiroergometric indexes. In all parameters followed we failed to prove any significant differences between the two groups. The treated children exhibited only slightly lower body height, higher body weight and higher percentage of body fat. They reached lower respiratory exchange ratio (R), with higher oxygen uptake on both submaximal and maximal load levels. Conclusions. When sufficiently motivated, children surviving five years after the treatment with anthracycline for ALL, who have no signs of cardiotoxic effects, have their functional cardiorespiratory capacity approximately comparable to that of healthy children.

        Key words: children, leukemia, anthracyclines, physical activity, spiroergometry.