The aim of this study was to determine the functional state of the feet of 40 boys aged 12 and 6 moths up to 13 and 6 months and by using the criterion variable of the 500 m run, to carry out a comparative analysis of their running speed. The subjects were divided into three groups: group I which numbered 14 boys with normal feet, group II which numbered 14 boys with high arches (pes excavatus) and group III numbering 12 boys with flat feet (pes planus). The diagnosis of the feet conditions was made following the inspection of the Achilles' tendon and the medial edge of the foot, followed by a plantogram. The statistical analysis of the results from the 500 m run was carried out by means of basic statistics, the analysis of variance (ANOVA) and the Ò criterion used to determine the source of the variability while testing the normality of the distribution. The analysis of the obtained results led us to the conclusion that foot deformities represent a negative factor for the ability to perform the 500m run which is one of the requirements in the battery of tests used in elementary schools. The analysis of variance, ANOVA, has indicated that there are significant differences between the boys in terms of their results for the 500 m run (p=.00). The difference between the average running time of the boys with normal feet and the boys with high arches is not statistically significant, while the differences between the average results of the run for the boys with normal and flat feet, as well as between the boys with high arches and flat feet are statistically significant, which led us to the conclusion that flat feet have a greater negative impact on the running ability than high arches. We can assume that boys with feet deformities (especially the ones with flat feet) will probably be less physically active than boys with high arches, which also leads to their significantly weaker running abilities.