Sprint Speed Measurement in a National Rugby Union Academy: An Equivalence Study of Three Measurement Systems, Age, and Playing Position.

Timing gates and local positioning systems (LPS) showed practical equivalence only for maximal velocity (Vmax), suggesting these two systems could be used interchangeably for this metric.

• Data were collected from 140 players using a 40 m sprint during a single testing day.
• Equivalence testing was used to interpret effects, with regions of practical equivalence informed by practitioner opinion of acceptable measurement error.
• No practical equivalence was found between timing gates and foot-mounted IMUs, or between LPS and IMUs for Vmax.
• The equivalence regions were informed by 'practitioner opinion of the acceptable amount of measurement error when measuring maximal speed and target change values for sprint times.'

All age-group differences in sprint and speed measures were not practically important among young male rugby union academy players.

• Players were from a national pathway academy and included multiple age groups.
• Effects were interpreted using equivalence testing rather than traditional null hypothesis significance testing.
• No age-group comparisons reached the threshold for practical importance across the measured variables.

Positional differences in sprint measures were not practically important, with 10-m sprint times being practically equivalent between backs and forwards.

• Playing position was categorized as backs and forwards.
• 10-m sprint times were specifically identified as practically equivalent between backs and forwards.
• Despite the typically assumed speed differences between positional groups, no practically important positional differences were found across measures.

The three measurement systems — timing gates, local positioning systems (LPS), and foot-mounted inertial measurement units (IMUs) — did not show broad equivalence across sprint metrics.

• Split times at 10 m, 20 m, 30 m, and 40 m were captured across all three systems.
• Vmax and time to Vmax (tVmax) were also compared across systems.
• Practical equivalence was found only for Vmax between timing gates and LPS, indicating the systems should not be used interchangeably for most metrics.
• The study emphasises 'the importance of measurement choice during speed profiling to inform speed and momentum development for young rugby players.'

The study collected anthropometric and sprint performance data including maximum momentum as part of a comprehensive speed profile of young male rugby union academy players.

• Data included age, body mass, and height as anthropometric measures.
• Sprint variables included split times at 10 m, 20 m, 30 m, and 40 m, Vmax, tVmax, and maximum momentum.
• A total of 140 players participated in data collection during a single testing day.
• The national pathway academy context was used to profile speed and momentum development.