How fast is fast? Defining velocity zones in women’s rugby league

ABSTRACT

Objectives

The study aimed to: 1) apply a data-mining approach to identify velocity zone thresholds for female rugby league players and 2) apply these velocity zones to examine the locomotor demands of match-play.

Methods

Microtechnology data were collected from elite female rugby league players representing all National Rugby League Women’s teams (n = 85 players; n = 224 files) over one season. Spectral clustering with a beta smoothing cut-off of 0.1 was applied to each player’s instantaneous match-play velocity data for the identification of four zones. To account for outliers within repeated data-points, the velocity zones for each player were calculated as the median. The overarching velocity zones were determined through an incremental search to minimise the root mean square error.

Results

Through a data-mining approach, four velocity zones were determined. Rounded to the nearest 0.5 km.h⁻¹ the velocity values across each zone were classified as low (<11.49 km.h⁻¹), moderate (11.50 to 17.49 km.h⁻¹), high (17.50 to 20.99 km.h⁻¹) and very-high (>21.00 km.h⁻¹). Practical application of the zones demonstrated positional group differences in the absolute (effect size (ES): 0.03 to 1.77) and relative (ES: 0.04 to 1.60) locomotor demands of match-play. The back positional group covered greater absolute and relative distances at a very-high velocity than all other positions.

Conclusions

This work informs the velocity zones that could be applied consistently to women’s rugby league data within practical (i.e., in the training and monitoring of players) and academic (i.e., as a model for future research to analyse locomotor demands) settings.

KEYWORDS:

• Female athlete
• global positioning system (GPS)
• microtechnology
• speed zone
• team sport

Disclosure statement

The dataset underpinning this work was routinely collected by the National Rugby League. The authors declare that Simon Buxton holds employment with the National Rugby League.

Practical applications

• Through a data-mining approach, this study identified four sex and sport-specific velocity zones for use in women’s rugby league. Rounded to the nearest 0.5 km.h⁻¹ the velocity values across each zone were classified as low (0 to 11.49 km.h⁻¹), moderate (11.50 to 17.49 km.h⁻¹), high (17.50 to 20.99 km.h⁻¹) and very-high (>21.00 km.h⁻¹).

• The consistent use of these velocity zones within both practice (i.e., in the training and monitoring of players) and academia (i.e., as a model for future research to analyse locomotor demands) will facilitate decision support systems surrounding the performance and wellbeing of female rugby league players.

Additional information

Funding

The authors reported that the National Rugby League provided support in the form of research funding for Cloe Cummins.