Concurrent Validity and Interunit Reliability of 25-Hz GNSS Units for Profiling Sprinting Performance

Area of Science:

• Sports Science
• Biomechanics
• Performance Analysis

Background:

• Accurate sprint profiling is essential for athlete development.
• Traditional measurement systems are often expensive or impractical for field use.
• Higher sampling rate Global Navigation Satellite System (GNSS) units may offer a solution.

Purpose of the Study:

• To evaluate the concurrent validity of 25-Hz GNSS units against criterion devices.
• To assess the interunit reliability of 25-Hz GNSS units.
• To determine the agreement of GNSS units for velocity and sprint time measurements.

Main Methods:

• Concurrent validity assessed using 30 athletes performing maximal 40-meter sprints with simultaneous measurement by GNSS, laser devices, and timing gates.
• Interunit reliability tested using three GNSS units on a vehicle during 60 accelerations (0-60 m).
• Statistical analysis included bias, typical error, and intraclass correlation coefficients (ICC).

Main Results:

• Low mean bias (<1%) and typical error (<2%) demonstrated excellent agreement between GNSS and criterion devices.
• Good to excellent interunit reliability was found for all interval times (0-10m to 10-60m), total sprint times (0-60m), and maximal sprint velocity (ICC values ranging from 0.86 to 1.0).
• The 25-Hz GNSS units showed high validity and reliability for profiling sprinting performance.

Conclusions:

• 25-Hz GNSS units are a valid, reliable, and feasible alternative to traditional sprint measurement devices.
• This technology enables scalable, concurrent assessment of multiple athletes' sprint performance in field settings.
• Coaches can utilize GNSS data for evidence-based decisions in athletic development and training.