CARDIORESPIRATORY FITNESS AND MUSCULAR STRENGTH OF GREEK PRIMARY SCHOOLCHILDREN IN RELATIONSHIP TO OBESITY AND SEDENTARY TIME

I. Iliadis¹, S. Chatziandrea¹, G. Pepera¹

Background: The way of life that people develop create a sense of concern for the public health due to the technologically developed and modernised sedentary lifestyle of humans in nowadays with an impact on the rise of diseases such as obesity.

Purpose: The purpose of τηισ study is to investigate the association of cardiorespiratory fitness and muscle strength with physique, and time of sedentary exposure to electronic devices in primary schoolchildren.

Methods: The sample of the study consisted of 105 Greek primary schoolchildren with a mean age of 10.52 ± 1.94 years of which 88 were boys (84%) and 17 girls (16%). Anthropometric characteristics were measured (height, weight and BMI, cardiorespiratory fitness (VO2max, 20m Shuttle Run Test (SRT)), handgrip strength and sedentary life based on the exposure to electronic devices with screen (self-completing questionnaire HELENA). Analysis of the Dispersion (ANOVA Post-Hoc Test) between the three groups (Normal, Overweight, Obese) was conducted based on the z-score for BMI and the following variables: right and left handgrip strength with VO2max. We used Multiple Linear Regression to calculate the value of cardiorespiratory fitness (VO2max) and handgrip strength both right and left. Finally, we used regression logistic analysis to determine the factors associated with poor SRT performance. Assessment tools: A questionnaire recording anthropometric characteristics was used. The assessment of cardiorespiratory fitness was carried out through the 20m Shuttle Run Test, while the evaluation of the handgrip strength was completed through the hand dynamometer. The evaluation of physical activity and sedentary time was done through a self-administered questionnaire.

Results: Βoth boys and girls in the normal BMI range (M = 47.58, SD = 3.26) had a statistically significant difference in their cardiorespiratory fitness compared to obese children (M = 44). , 78, SD = 3.23) 5.6 (95% CI 0.9 to 4.7) but not with those who were overweight (M = 46.18, SD = 2.86) 3.35 (95% CI -0.3 to 3). Cardiorespiratory fitness was shown to be statistically significantly affected by BMI (r = -0.338, p <0.05) and sedentary time (r = -0.313, p <0.05). Muscular grip strength appeared to be affected only by sitting time in both the right (r = 0.325, p <0.05) and left arm (r = 0.330, p <0.05). Finally, it was found that only a sitting time of 1.057 (95% CI 1.009 to 1.108, p <0.05) affects cardiorespiratory fitness, i.e it is the strongest factor to change a participant category (fit, unfit) in cardiorespiratory fitness.

Conclusion(s): Based on the results of the above measurements, it was observed that obese children of both sexes had lower cardiorespiratory fitness than children with lower BMI. Sedentary time appeared to be positively correlated with muscular grip strength in both arms, while negatively correlated with cardiorespiratory fitness.

Implications: Both school and extracurricular activities that lead to a healthier life style could be promoted. Increasing the time that children spend on sports, and therefore a consequent reduction of sedentary activities, is a measure in this direction.

Funding, acknowledgements: No funding to declare

Keywords: cardiorespiratory fitness

Topic: Paediatrics

Did this work require ethics approval? Yes

Institution: University of Thessaly

Committee: Ethics Commitee of the University of Thessaly

Ethics number: 308ΣΕ2/27-01-2020