Comparison of the FitBit Zip to the ActiCal accelerometer in children and adults

Giannini, Andrew
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University of Delaware
Portable fitness-tracking devices are part of a broader category of wearable technological devices. The wearable device industry is poised to explode and research firms such as Juniper and IMS predict wearable devices to be a multi-billion dollar industry by 2016. Newly released portable fitness-tracking devices claim to measure various physical activity related variables including energy expenditure and total activity time. With growing concern for obesity prevention, the availability and affordability of these devices could allow children and adults to monitor their physical activity to ensure they meet published guidelines related to physical activity. This study proposed using the Actical accelerometer to validate the accuracy of the FitBit Zip measurements. Participants included healthy children between the ages of 8 and 14 years and healthy adults between the ages of 18 and 40 years. Each participant was fitted with an ActiCal accelerometer and FitBit Zip device and each participant performed a physical activity protocol consisting of sedentary, light, moderate, and vigorous intensities. Laboratory accelerometers, such as the ActiCal accelerometer, are a valid tool in measuring the physical activity in children and adults whereas research is lacking in providing documented validity of the FitBit Zip.