Evolution of the Correlation Between Body Mass Index (BMI) and Agility of Primary School Students in North-Eastern Romania

Interacting with children's cognitive processes and mental health status, body mass index (BMI) could be analyzed in relation to motor performance. This study aims to analyse the relationship between BMI and agility of primary school students in the northeast of Romania. Hypothesis testing was done by analyzing data obtained from 3250 pupils (1605 girls and 1645 boys) aged 6 to 11 years old from the North-East of Romania. BMI was calculated based on height and weight, as well as agility through the 505 change of direction speed test. The sample was divided according to gender and age, and the differences and correlations were analysed. We assumed that our sample has a significant correlation of BMI with agility and that its strength increases with age, based on neural maturation. Children's results showed gender- and age-determined differences in anthropometric as well as motor skills. The development of Romanian girls and boys differs punctually at this stage, with the two genders having close BMI values at age 11. The time to complete the 505 test is close at age 6, with boys performing better by age 11. The correlation between BMI and agility has weak strength in the 6-11 years age group of Romanian students. It is significant in girls at 9 (r = 0.20) and 10 years (r = 0.15), and in boys from 7 (r = 0.20) to 10 years (r = 0.22). The data partially confirm our hypothesis, with the correlation existing in the 7-10 years age range, its strength having a fluctuating evolution. At 11 years the link between BMI and agility ceases to exist.