aerobic fitness and cardiorespiratory function of pediatric cancer survivors introduction overall more than 80 of children diagnosed with cancer will survive their immediate disease this growing group of childhood cancer survivors is at an increased risk for several chronic diseases and increased mortality physical activity is a wellknown and powerful means to reduce such complications yet many children are not active as recommended furthermore the complex treatments might adversely affect the heart and lungs possibly limiting physical performanceaim to measure aerobic fitness among childhood cancer survivors while assessing maximal cardiac and respiratory functionsmethods eighteen children mean age 115 21 years 50 males who had completed medical treatment for cancer and 16 healthy children performed a cardiorespiratory exercise test on a bicycle ergometer until exhaustion peak oxygen uptake o2 pulse and several ventilatory parameters were measured and compared between the groupsresults the mean maximal load obtained by the cancer survivor group was lower than expected compared with controls 89 19 vs 101 18 p 0055 peak oxygen consumption was also lower with a marginal statistical significance 333 75 vs 389 97 ml o2kgmin p 0075 yet was significantly lower when expressed as a percent of age and sex appropriate norms 78 15 vs 94 16 p 00081 cardiac and respiratory functions were normal in all children with no betweengroup differencesconclusions we conclude that aerobic fitness is lower in children who have survived cancer with no evidence of significant cardiac or lung damage given the importance of regular physical activity for this atrisk population it should be continuously encouraged while administering a personally tailored exercise prescription