摘要：The goal of this study was to determine differences of some anthropometric characteristics and motor abilities in boys aged between 14 and 15 during a period of 6 months. Data obtained through this study shall provide a response as to whether the observed chronological age is adequate for intensifying water and dry land training. For that purpose, 39 swimmers belonging to Zagreb swim clubs, aged between 14 and 15, were measured using a battery of 23 anthropometric dimensions, including bone length, bone width, body volume and mass, as well as subcutaneous adipose tissue. In order to assess motor abilities, 10 tests were taken. Descriptive statistical indicators have shown an extremely high variability of all measured characteristics and abilities, some of which have demonstrated irregular distribution of results. Student s T-test for dependant samples determined that all measures of bone length, bone width and body volume and mass are showing statistically significant differences with regard to increase in values. Measures of subcutaneous adipose tissue are decreasing with statistical significance when extremities are concerned, while skin folds on the trunk are not showing any statistically significant difference. In the analysis of variations between motor test results, back extensions, squats during 60 seconds and twists with the stick have not shown statistical significance, while others have shown statistically significant differences between the first and second measuring (p 0,05). Canonical analysis of the first and second measuring indicates that within each measuring there is one statistically significant pair of factors between these two sets of variables (p 0.05). However, the structure of individual factors shows that significant changes had set in with regard to the relationship of the two observed sets of variables.
