Accuracy Verification of the Smartphone (S Health) App : Focusing on Step Count and Energy Expenditure

This study aimed to verify the accuracy of step count and energy expenditure measurements by the S Health app and to explore its potential as a tool for physical activity measurement research. The study targeted 20 adults (aged 19 to 64 years) living in Daegu Metropolitan City (Age: 26.0±5.8 years, Height: 170.2±7.2 cm, Weight: 69.5±10.9 kg, BMI: 20.4±2.8 kg/m²). To verify the accuracy of the S Health app, the step counts obtained through video analysis of a 2km walk were compared with the step counts from the S Health app and a pedometer. For energy expenditure, the S Health app, accelerometer, and respiratory gas analyzer were used and compared during treadmill walking.BR/ The results are as follows: Firstly, in the comparison of step count differences, there was a significant difference between the S Health app, actual step count, and pedometer (p.000). The S Health app tended to underestimate the step count.BR/ Secondly, in the comparison of energy expenditure, there was a significant difference between the respiratory gas analyzer, S Health app, and accelerometer (p.000). The energy expenditure measured by the respiratory gas analyzer was higher, whereas the smartphone app and accelerometer provided conservative measurements.BR/ In summary, the S Health app showed discrepancies in measuring step count and energy expenditure. These results can vary depending on the body position, walking intensity, smartphone model, and manufacturer's motion sensor quality. For more accurate verification, further research involving various environments and age groups (children, elderly, etc.) is necessary.