Peterson, CarlPyne, DavidPortus, Marc JDawson , Brian2015-12-081555-0265http://hdl.handle.net/1885/32450Purpose: The validity and reliability of three commercial global positioning system (GPS) units (MinimaxX, Catapult, Australia; SPI-IO, SPI-Pro, GPSports, Australia) were quantified. Methods: Twenty trials of cricket-specific locomotion patterns and distances (walking 8800 m, jogging 2400 m, running 1200 m, striding 600 m, sprinting 20- to 40-m intervals, and run-a-three) were compared against criterion measures (400-m athletic track, electronic timing). Validity was quantified with the standard error of the estimate (SEE) and reliability estimated using typical error expressed as a coefficient of variation. Results: The validity (mean ± 90% confidence limits) for locomotion patterns walking to striding ranged from 0.4 ± 0.1 to 3.8 ± 1.4%, whereas for sprinting distances over 20 to 40 m including run-a-three (approx. 50 m) the SEE ranged from 2.6 ± 1.0 to 23.8 ± 8.8%. The reliability (expressed as mean [90% confidence limits]) of estimating distance traveled by walking to striding ranged from 0.3 (0.2 to 0.4) to 2.9% (2.3 to 4.0). Similarly, mean reliability of estimating different sprinting distances over 20 to 40 m ranged from 2.0 (1.6 to 2.8) to 30.0% (23.2 to 43.3). Conclusions: The accuracy and bias was dependent on the GPS brand employed. Commercially available GPS units have acceptable validity and reliability for estimating longer distances (600-8800 m) in walking to striding, but require further development for shorter cricket-specific sprinting distances.Keywords: adult; article; athletic performance; comparative study; geographic information system; human; instrumentation; male; movement (physiology); physiology; reproducibility; task performance; Adult; Athletic Performance; Geographic Information Systems; Humans Accuracy; Precision; Tracking20092016-02-24