Validity and Reliability of GPS Devices for Measuring Movement Demands of Team Sports

Coutts A.J., Duffield R.

Objective:
The study aimed to assess the validity and intra-model reliability of different GPS devices for quantifying high-intensity, intermittent exercise performance in team sports.

Methods:

Two moderately trained males completed eight bouts of a standard circuit involving intermittent exercise.
The circuit consisted of six laps around a 128.5-m course.
Distance and speed were collected concurrently at 1 Hz using six GPS devices (2 SPI-10, 2 SPI Elite, and 2 WiSPI, GPSports, Canberra, Australia).
Performance measures included total distance covered for each bout and each lap, high-intensity running distance (>14.4 km/h, HIR), and very high-intensity running distance (>20 km/h, VHIR) during each bout.
Peak speed was measured during a 20-m sprint at the start of each lap of the circuit.
Actual distance was measured using a measuring tape.
Results:

Mean circuit total distance was significantly different between each of the GPS devices (p < 0.001); however, all devices were within 5 m of the actual lap distance and had a good level of reliability (coefficient of variation (CV) < 5%). The CV for total distance (3.6–7.1%) and peak speed (2.3–5.8%) was good-to-moderate, but poor for HIR (11.2–32.4%) and VHIR (11.5–30.4%) for all GPS devices. The results indicate that GPS devices have an acceptable level of accuracy and reliability for total distance and peak speeds during high-intensity, intermittent exercise but may not provide reliable measures for higher intensity activities. Conclusion: GPS devices show acceptable accuracy and reliability for measuring total distance and peak speeds during high-intensity, intermittent exercise in team sports. However, caution is needed when interpreting data for higher intensity activities.