Physical activity and fitness in obese children

Daily physical activity and physical fitness were studied in 31 obese and 31 normal-weight children matched for age and sex. The ages of the children ranged from 5.7 to 16.1 years. The history of their physical activity was examined using a questionnaire completed by the child and the parents. Physical fitness was measured using a two-stage exercise test on a bicycle ergometer. There were no significant differences in daily activities between the obese and the non-obese children, while the sports grades at school were lower and participation in the training teams of sports clubs was less frequent among obese than normal-weight subjects. The obese children were physically less fit than the normal-weight subjects as judged from the pedalling time in exercise test (P less than 0.05) and from the maximum oxygen consumption (VO2 max) related to lean body mass (LBM) (P less than 0.001). Twenty-seven children participated for 1 year in a weight-reduction programme which comprised individual nutrition counselling, guidance on physical activities and supportive therapy. The reduction in weight was successful in 25 out of 27 children and VO2 max increased on average from 44.2 to 47.1 ml/min/kg of LBM (P less than 0.025). There was no change in the time used for physical activities during the weight reduction period although the children's participation in the training teams of sports clubs increased. It was concluded that obese children are less fit than their non-obese counterparts. Weight reduction results, however, in an improvement of the maximum oxygen consumption towards normal.