The relationship between body fat percentage and some anthropometric and physical fitness characteristics in pre-and peripubertal boys

The main aim of this study was to compare anthropometric and physical fitness indicators of boys of the same chronical age but with different fat percentages. Subjects were Hungarian boys aged 9–13 years (N = 6919). Anthropometry was measured according the guidelines of the International Biological Program. Relative body fat was estimated by Drinkwater–Ross’s method (1980); Conrad’s growth type of physique was also estimated (1963). Physical fitness was tested with 30 m dash (s), standing long jump (cm), fistball throw (m), and 1200 m run (s). Subjects of each cohort were grouped into seven subgroups with fat percentage ranges of 4%. Differences between subgroups were tested by one-way ANOVA. In the case of a significant F-test, Tukey’s post-hoc tests were used. The level of effective random error was set at 5% in all significance tests (p < 0.05). Except for the three groups with low fat percentages, values of body weight, stature, body mass index, and plastic and metric indexes were significantly higher; results of 30 m, 1200 m running, and standing long jump were worse in all groups with higher fat percentages. An interesting finding of the current study is that body fat percentage also influenced the physical fitness of non-overweight and obese children as well when using merely the 4% ranges in grouping by fatness. The lower the fat the better the physical fitness was in this sample of pre-and peripubertal boys.