Validity of Two Kinds of Physical Activity Tracker for Measuring Total Calorie Expenditures and Activities above Moderate Intensity

ABSTRACT

OBJECTIVE: To evaluate the validity of two kinds of physical activity trackers (PAT) during treadmill exercise. METHOD: 14 healthy people performed cardiopulmonary exercise test by means of Bruce protocol. The omnidirectional PATs were placed onto the right wrist and ankle, and the temperature sensing PATs were placed onto the right arm and lower leg. Simultaneous measurement of body motion was continuously recorded during cardiopulmonary exercise test. Then we checked total calorie expenditure and duration above moderated intensity activity (>3 METs) from each PATs and gas analyzer. RESULTS: Total calorie expenditures of PAT were significantly underestimated than gas analyzer, except the temperature sensing PAT applied onto the leg, but all of them showed significant correlation. The duration above moderate intensity activity of the PAT did not show significant difference comparing with gas analyzer, except the omnidirectional PAT applied onto the arm, but all of them showed significant correlation. CONCLUSION: Both omnidirectional PATs and temperature sensing PATs could estimate the total calorie expenditure and the duration above moderate intensity activity. But it is necessary to apply exercise-specific protocol to PAT to enhance the accuracy of estimating energy expenditure during periods of exercise.