Validity of a wearable accelerometer device to measure average acceleration values during high speed running

The aim of this study was to determine the validity of an accelerometer to measure average acceleration values during high speed running. Thirteen subjects performed three sprint efforts over a 40 m distance (n = 39). Acceleration was measured using a 100 Hz tri-axial accelerometer integrated within a wearable tracking device (SPI-HPU, GPSports, Canberra). To provide a concurrent measure of acceleration, timing gates were positioned at 10 m intervals (0 m - 40 m). Accelerometer data collected during 0 m - 10 m and 10 m - 20 m provided a measure of average acceleration values. Accelerometer data was recorded as the raw output and filtered by applying a 3 point moving average and a 10 point moving average. The accelerometer could not measure average acceleration values during high speed running. The accelerometer significantly overestimated average acceleration values during both 0 m - 10 m and 10 m - 20 m, regardless of the data filtering technique (p < 0.001). Body mass significantly affected all accelerometer variables (p < 0.10, partial η = 0.091 - 0.219). Body mass and the absence of a gravity compensation formula affect the accuracy and practicality of accelerometers. Until GPSports integrated accelerometers incorporate a gravity compensation formula the usefulness of any accelerometer derived algorithms is questionable.