Accuracy of Accelerometer for the Prediction of Energy Expenditure and Activity Intensity in Athletic Elementary School Children During Selected Activities / 대한지역사회영양학회지

OBJECTIVES: Accurate assessment of energy expenditure is important for estimation of energy requirements in athletic children. The objective of this study was to evaluate the accuracy of accelerometer for prediction of selected activities' energy expenditure and intensity in athletic elementary school children. METHODS: The present study involved 31 soccer players (16 males and 15 females) from an elementary school (9-12 years). During the measurements, children performed eight selected activities while simultaneously wearing the accelerometer and carrying the portable indirect calorimeter. Five equations (Freedson/Trost, Treuth, Pate, Puyau, Mattocks) were assessed for the prediction of energy expenditure from accelerometer counts, while Evenson equation was added for prediction of activity intensity, making msix equations in total. The accuracy of accelerometer for energy prediction was assessed by comparing measured and predicted values, using the paired t-test. The intensity classification accuracy was evaluated with kappa statistics and ROC-Curve. RESULTS: For activities of lying down, television viewing and reading, Freedson/Trost, Treuth were accurate in predicting energy expenditure. Regarding Pate, it was accurate for vacuuming and slow treadmill walking energy prediction. Mattocks was accurate in treadmill running activities. Concerning activity intensity classification accuracy, Pate (kappa=0.72) had the best performance across the four intensities (sedentary, light, moderate, vigorous). In case of the sedentary activities, all equations had a good prediction accuracy, while with light activities and Vigorous activities, Pate had an excellent accuracy (ROC-AUC=0.91, 0.94). For Moderate activities, all equations showed a poor performance. CONCLUSIONS: In conclusion, none of the assessed equations was accurate in predicting energy expenditure across all assessed activities in athletic children. For activity intensity classification, Pate had the best prediction accuracy.

Comparison of Physical Activity Level, Physical Activity Pattern and Energy Expenditure in Male and Female Elementary School Soccer Players using Accelerometer and Physical Activity Diary / 대한지역사회영양학회지

OBJECTIVES: The purpose of this study was to compare the physical activity level (PAL), the physical activity pattern and the energy expenditure in male and female elementary school soccer players using the accelerometer and the physical activity diary. METHODS: Twenty-five (male 11, female 14) elementary school soccer players (9–12 years) participated in this study. During their daily activities, they wore an accelerometer for seven days (five weekdays and two weekend days) and completed the physical activity diary for three days (two weekdays and one weekend day). PAL was calculated by using the physical activity diary and three equations (Pate Preschool, Freedson Children, and Freedson) were used to calculate the intensity of physical activity and energy expenditure from the counts of accelerometer. RESULTS: The average of physical activity by day of the week, CPM (Counts Per Minute) and METs (Metabolic Equivalents) were significantly higher in males (723.3 ± 149.2 CPM, 2.07 ± 0.18 METs) compared to females (505.6 ± 119.9 CPM, 1.79 ± 0.20 METs), but there was no significant difference in PAEE (Physical Activity Energy Expenditure) between the two groups (males: 15.5 ± 9.1 kcal/day, females: 11.5 ± 6.0 kcal/day). During weekdays, physical activity intensity was significantly higher in males compared to females at lunch time and training time than at other times. In both genders, the PAL was higher during weekdays (males 1.98, females 1.89) compared to weekend (males 1.62, females 1.61) (p<0.05). CONCLUSIONS: Our study observations suggest the necessity to develop an accelerometer equation for accurately evaluating the physical activity of elementary school athletes.