Variability of Physical Performance and Player Match Loads in Professional Rugby Union

McLaren, S. J.; Weston, M.; Smith, A.; Cram, R.; Portas, M. D.

The objective of this study was to investigate the variability of physical performance and match loads within and between professional rugby union players.

Using microsensors, data were collected from 28 male professional rugby players over 15 competitive matches. The variables analyzed included total distance covered, distance covered at different speed thresholds (low-speed, high-speed, and very high-speed running), total impacts, repeated high-intensity efforts, body load (PlayerLoadTM), and low-velocity body load. Ratings of perceived exertion were used to represent internal match loads. Variability was assessed using the coefficient of variation, and meaningful changes in physical performance and match loads were determined using magnitude-based inferences.

The results indicated large between-match variation within players for high-speed running distance, very high-speed running distance, total impacts, and repeated high-intensity efforts, with moderate variability for match ratings of perceived exertion, body load, and low-velocity body load. Threshold values for likely substantial between-match changes in high-intensity physical performance measures ranged from 21% to 76%, while changes in ratings of perceived exertion, body load, and low-velocity body load were around 10%.

In conclusion, the study found that within- and between-player variability in high-intensity activity in professional rugby union is significant. However, ratings of perceived exertion, body load, and low-velocity body load appear to be more stable and may be interpreted with greater accuracy.