Abstract:

The body health-related fitness consists of the following four components: cardiovascular fitness, muscle fitness, flexibility, and body composition. Our research focuses on the last named component of body health-oriented fitness, namely body composition. The level of this component highly correlates mainly with cardiovascular and muscular fitness.

Paediatricians in European countries have experienced a relatively rapid increase in the number of overweight and obese children. Many regions have responded to this situation, both with the recommended dietary practices, and practical measures, for example in school canteens.

The goal of our research is to assess trends in the development of physical characteristics (body height, weight and BMI) in physically active and physically inactive children. Our research was longitudinal; pupils were measured for the first time in the 1st grade, and for the second time in the 5th grade of primary school.

The research sample consisted of 175 probands (n=175) from primary schools in the Pilsen region, of which 88 were boys and 87 were girls. The first measurement was conducted in pupils from the 1st grade of primary school, roughly in the age range of 6-7 years. The second measurement was conducted in the same pupils from the 5th grade, in the age range of 10-11 years. 110 pupils (n1=110) reported leisure-time physical activities, performed for at least twice a week, both in the 1st and 5th grades, and 65 pupils (n2=65) reported organised physical activities, performed once a week or not at all.

Our research was conducted over the period of four years on the same sample of pupils from Pilsen primary schools. From the obtained values of body height, and body weight, the body mass index (BMI) and percentile were determined and compared with a valid Czech Republic standard. According to the percentile of the BMI value, the pupils were divided to the groups of underweight, normal weight, overweight and obesity pupils.

To compare the body weight, body height and BMI variables in physically active and physically inactive pupils, the t-test for independent selections was used. To express the incidence rate of underweight, normal weight, overweight, and obese pupils in the groups of physically active and inactive boys and girls, we converted the absolute rate to percentages.

The results of the t-test have showed that there is a significant difference in the BMI value of pupils in the 5th grade. The percentage of physically active pupils with normal weight were 92% in 1st grade and 87.5% in 5th grade, and the relative representation of physically inactive pupils with normal weight was lower, namely 79.2% in 1st grade and only 61.4% in 5th grade. When determining the proportion of overweight and obese pupils, the percentage of physically active pupils were 5.1% in 1st grade and 9.5% in the 5th grade, and, in physically inactive pupils, this relative number was increased up to 13.8% in the 1st grade and 36.2% in 5th grade.

We have determined that the number of overweight and obese children significantly increased in physically inactive pupils, and the number of children with normal weight decreased over the period of four years. The BMI also significantly differs among physically active and inactive pupils in the 5th grade. It is evident that leisure-time physical activity is an essential part of proper physical development and body composition already among younger school-age children.

Keywords:

Body-Mass Index, younger school-age children, body high, body weight.