Physical fitness of overweight and underweight preschool children from southern Poland.

The main aim of this study was to assess differences in the level of physical fitness between children of preschool age with different BMI, as overweight and obesity are an increasing problem even in this age group. The study group consisted of 3,945 children aged 4 to 6 years living in southern Poland. Analysis included the results of body height and weight measurements (from which BMI was calculated) and motor skills tests: sit-and-reach test, standing broad jump and handgrip strength. Children were grouped according to the Obesity Task Force categories. Significant differences in body height were visible (i) between overweight and normal children and (ii) between overweight and underweight children. In terms of body weight and BMI, significant differences existed between all groups. With regard to fitness tests, the greatest differences were observed for handgrip strength and standing broad jump. The sit-and-reach test did not reveal any differences between the groups. The results showed that overall physical fitness was negatively correlated with relative weight; general fitness in overweight children was lower than in normal or underweight children. As it is obvious that physical activity is indispensable even for preschool children, any increase in physical activity could at least partially alleviate the problem of excessive weight and improve the general fitness of children. In the future this would reduce the incidence of diseases related to obesity and a lack of exercise.