Validity and Reliability of Global Positioning System Units (STATSports Viper) for Measuring Distance and Peak Speed in Sports

Beato M., Devereux G., Stiff A.

Objective:
The aim of this study is to assess the validity and reliability of GPS units (STATSports Viper) for measuring distance and peak speed in sports.

Participants:
Twenty participants were enrolled, with an average age of 21 years (range 18 to 24 years), body mass of 73 kg, and height of 1.78 m.

Methodology:

GPS Validity: Instantaneous speed values (peak speed) determined by GPS (10 Hz, Viper Units; STATSports, Newry, Ireland) were compared with those determined by a radar gun during a 20-m sprint, using the Stalker ATS Version 5.0.3.0 software as the gold standard.
Distance Validity: Distance recorded by GPS was compared with known circuit distances in a 400-m running trial, a 128.5-m sports-specific circuit, and a 20-m linear running trial.
Results:

Distance Bias:
400-m trial: 1.99 ± 1.81%
128.5-m circuit: 2.7 ± 1.2%
20-m trial: 1.26 ± 1.04%
Peak Speed:
GPS: 26.3 ± 2.4 km/h
Criterion: 26.1 ± 2.6 km/h
Bias: 1.80 ± 1.93%
Findings:

The GPS did not underestimate the criterion distance in any of the trials, including the 400-m trial, 128.5-m circuit, and 20-m trial, as well as peak speed.
Small errors (less than 5%) were found for peak speed and distances.
The study supported the validity and reliability of the GPS model used.