Insufficient level of physical activity has been identified to be one of the leading risk factor for global mortality worldwide (1). The rising levels of childhood obesity are likely to have major public health consequences since being overweight during childhood will most likely continue into adulthood. Low scoring in physical fitness tests are important risk factor for many diseases like diabetes, cancer, high blood pressure, osteoporosis, lipid disorders, depression, anxiety etc (1).

Positive secular trends in height and weight have occurred in all socioeconomic groups in the first half of the twentieth century (2). The changes recorded from the 1960's through the 2000's are variable among countries (2). Secular changes were remarkably similar for boys and girls, and there is no doubt that children are becoming fatter (1, 3), so it’s questionable if we could call this trend the" positive" one. With this trend, it would be surprising if performance on jumping tests were not declining (4). The trend of a decrease in acceleration has also been confirmed in some other studies on secular height trend conducted in Serbia (5, 6). Unfavorable trends in children's weight status have been documented in many countries. Overweight prevalence remained high in most developed countries in the world (7). An increase was observed for both boys and girls (3, 7). However, in recent years, a stabilization in overweight prevalence has been suggested by researches from several different countries (8, 9). Some researchers suggest that this plateau in overweight prevalence may mask an increase in certain vulnerable groups of children (10).