Ivan Prskalo

Heart Rate–Corrected QT and JT Intervals in Electrocardiograms in Physically Fit Students and Student Athletes

In literature, data on the prevalence of prolonged and shortened corrected QT (QTc) have shown considerable variability. The aim of the study was to compare QTc and JTc intervals of competitive student athletes and noncompetitive sport participants to QTc cutoff points used in athletes. A group of 485 physically fit candidates for the study of kinesiology (139 female and 346 male candidates) aged 18–20 participated in the study. Basic anthropometry, field fitness test, cardiovascular, electrocardiograms measurements, and blood sampling for lipid profile were conducted. The prolonged QTc according to European Society of Cardiology criteria was found in 2.9% of female and 4.3% of male students. When the “Seattle criteria” were used, the proportion of prolonged QTc was 1.44% in female and 0.29% in male students. The shortened QTc according to the Seattle cutoff points was presented in 0.7% of female and 2.0% of male students. The JTc over 400 ms was found in 0.72% of female and 0.29% of male students. The JTc shorter than 320 ms was presented in 0.7% of female and 1.1% of male students. No significant differences were found between students involved in competitive sport and those involved in recreational sporting activities. Female students had lower body mass index and blood pressure values, better blood lipid profile, and lower uric acid concentrations. In conclusion, the Seattle criteria markedly decreased the proportion of prolonged QTc in student athletes, particularly in male students. It seems that the JTc interval could be a better parameter than the QTc interval for the estimation of specific repolarization time in physically fit university students.

Comparison of Maximum Oxygen Intake (VO2max) In Ten and Fourteen-Year-Old Girls // Usporedba maksimalnog primitka kisika (VO2max) djevojčica dobi 10 i 14 godina

The objective of the present research was to determine whether aerobic capacity of fourteen-year-old girls is higher than that of ten-year-old girls. The research aimed to establish if the level of cardio respiratory fitness in girls decreases with age, and if their overall physical activity also decreases. A low level of cardio respiratory fitness from an early age has been confirmed in a number of studies, and it has been highly correlated with a sedentary lifestyle. Research participants were 94 fourth and eighth grade primary school girls. The variables were anthropometric measures for body height, body weight, waist circumference, and hips circumference. All the measurements were done in accordance with the International Biological Program (IBP). Body fat percentage (BF%) was also measured with the Omron (Type BF511, Japan). A multistage 20m shuttle run test was used to obtain the values for aerobic capacity, and PAQ-C questionnaire was used to estimate the level of physical activity. The results indicate that only 5% of female students meet the recommendations for physical activity while 83% engage in moderate physical activity. Statistically significant differences were determined for the variables used to estimate the aerobic capacity, with ten-year-old girls (p=0.00) having better aerobic capacity than the fourteen-year-old girls. Furthermore, ten-year-old girls were found to be significantly more physically active (p=0.00). The results of the correlation test between the aerobic capacity (VO2 max) and the overall physical activity (PA) indicate significant positive correlation (r = 0.42; p = 0.00). Girls who do not engage in physical activity at least for the recommended 60 minutes need to be directed towards various forms of healthy lifestyle with a special emphasis on everyday physical exercise that may increase their aerobic capacity.

The dynamics of indicators of nutritional status in elementary school pupils

Poor nutritional status is a major problem currently faced by children, so the aim of this research was to determine the dynamics of nutritional status indicators in one generation of elementary school children. The study was conducted on a sample of 107 school children observed for four years. Body height, body mass, back skinfold, forearm skinfold and arm circumference were measured. Body mass index and body fat percentage were also measured and the children’s nutritional status was determined. Trend analysis of nutritional status indicators was performed by polynomial regression analysis. Study results showed that the participants’ nutritional status estimated by body mass index and body fat percentage diff ered and that there was a signifi cant infl uence of time on the indicators of nutritional status in both genders. Poor nutritional status was more frequently recorded in boys than in girls, unlike several years ago when girls had poorer nutritional status than boys

Kinesiological Activities and Leisure Time of Young School-Age Pupils in 2007 and 2012 / Kineziološki sadržaji i slobodno vrijeme učenica i učenika mlađe školske dobi u 2007. i 2012. godini

The paper presents a research conducted in 2007 and then again in 2012 on a sample of 628 male and female primary school pupils from the first to fourth grade (ages 7-10). The obtained results showed a low frequency of the responses that ranked Physical Education (PE) as the most significant subject for the pupils’ future life: 13% in 2007 and 18% in 2012. Preference for the subject was reduced significantly from 37% in 2007 to 27% in 2012. Spending free time in 2012 in a typically static activity was significantly more common (44%) than doing any kinesiological activity (25%) as opposed to 2007 when the percentage for static activities was 27% and for doing kinesiological activities it was 17%. Since the contemporary society is characterized by obesity and different health related disorders, with the problem increasingly becoming widespread among the young, the situation is consequently even more serious. Leisure time of children and the youth increasingly implies activities that require little or no muscular effort. Gender was confirmed as an important factor in the preference for the subject but not in the estimate of its importance according to the results obtained in 2012. Thereby, there still seems to be a significantly smaller number of pupils joining extra-curricular kinesiological activities at school than those joining out-of-school kinesiological activities. It is a further indication of the unwillingness of schools to satisfy their pupils’ needs. However, the consequences of the contemporary lifestyle can be substantially compensated through kinesiological programmes. It is therefore necessary to accept the fact that one of the basic educational objectives of a school is to help pupils develop a habit of physical exercise, which should subsequently become the basis of a positive lifelong habit of engaging in physical exercise on a daily basis.