title: Accuracy of GPS devices for measuring high-intensity running in field-based team sports.
abstract: We compared the accuracy of 2 GPS systems with different sampling rates for the determination of distances covered at high-speed and metabolic power derived from a combination of running speed and acceleration. 8 participants performed 56 bouts of shuttle intermittent running wearing 2 portable GPS devices (SPI-Pro, GPS-5 Hz and MinimaxX, GPS-10 Hz). The GPS systems were compared with a radar system as a criterion measure. The variables investigated were: total distance (TD), high-speed distance (HSR>4.17 m·s(-1)), very high-speed distance (VHSR>5.56 m·s(-1)), mean power (Pmean), high metabolic power (HMP>20 W·kg(-1)) and very high metabolic power (VHMP>25 W·kg(-1)). GPS-5 Hz had low error for TD (2.8%) and Pmean (4.5%), while the errors for the other variables ranged from moderate to high (7.5-23.2%). GPS-10 Hz demonstrated a low error for TD (1.9%), HSR (4.7%), Pmean (2.4%) and HMP (4.5%), whereas the errors for VHSR (10.5%) and VHMP (6.2%) were moderate. In general, GPS accuracy increased with a higher sampling rate, but decreased with increasing speed of movement. Both systems could be used for calculating TD and Pmean, but they cannot be used interchangeably. Only GPS-10 Hz demonstrated a sufficient level of accuracy for quantifying distance covered at higher speeds or time spent at very high power.
authors.affiliation: S. S. MAPEI srl, Human Performance Laboratory, Olgiate Olona, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Rampinini
authors.affiliation: Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milano, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Alberti
authors.affiliation: Faculty of Exercise Sciences, Department of Sport, Università degli Studi di Milano, Nutrition and Health Sciences, Milan, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Fiorenza
authors.affiliation: S. S. MAPEI srl, Human Performance Laboratory, Castellanza, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Riggio
authors.affiliation: Training Check Juventus, Juventus Football Club, Turin, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Sassi
authors.affiliation: School of Leisure, Sport & Tourism, University of Technology, Sydney, Australia.
authors.forename: T O
authors.initials: TO
authors.lastname: Borges
authors.affiliation: School of Leisure, Sport & Tourism, University of Technology, Sydney, Lindfield, Australia.
authors.forename: A J
authors.initials: AJ
authors.lastname: Coutts
mesh_terms: D000054:Acceleration; D000293:Adolescent; D004734:Energy Metabolism; D040362:Geographic Information Systems; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012420:Running / Q000502:physiology*; D012916:Soccer / Q000502:physiology*; D013996:Time and Motion Studies