The positive consequences of the changes of secular trend are well-known in Hungary as well in our days. The understanding of secular trend is not restricted only to the morphological differences, but also the variabilities of physiological functions and measurable physical performances. Nowadays it is considered an evidence that one of the external conditions of a harmonic development of child is the regular physical activity.

This study aimed to examine: how did the secular trend effect the motoric performance of prepubertal boys aged between 1975 and 2000.

It was revealed that during this period both the height and body mass have increased generation by generation. However, the positive evaluation of this finding is questioned due to the measured lower physical performances. The most critical element was the significant decrease of 1200-m running results that indicate the cardio-respiratoric endurance.

The results show the strength of the social factors that maintain the trend of inactivity. To change this trend, it is necessary to influence the public understanding and take a series of measures, such as improving school physical education and sport, preparing aerobic power-based programs. This problem is not simply an elite sport issue, but it is also fundamental for the public health.