• The effects of physical contact type on the internal and external demands during a rugby league match simulation protocol.

      Norris, Jonathan; Highton, Jamie M.; Hughes, Stephen F.; Twist, Craig; University of Chester (Taylor and Francis, 2016-02-09)
      This study investigated how the type of contact influences physiological, perceptual and locomotive demands during a simulated rugby league match. Eleven male university rugby league players performed two trials of the rugby league movement simulation protocol for forwards (RLMSP-i) with a traditional soft tackle bag (BAG) and a weighted tackle sled (SLED) to replicate contact demands. Locomotive rate, sprint speed, tackle intensity, heart rate, rating of perceived exertion and blood lactate concentration were analysed in four periods during the first and second bout of both trials. Countermovement jump (CMJ) was measured before and immediately after each trial. More time was spent in heart rate zone between 90 – 100% HRpeak during the first (effect size ± 95% confidence interval: 0.44 ± 0.49) and second bout (0.44 ± 0.43), and larger (0.6 ± 0.69) decrements in CMJ performance were observed during SLED (5.9, s = 4.9%) compared to BAG (2.6, s = 5.4%). Sprint into contact speed was faster during BAG compared to SLED in the first (1.10 ± 0.92) and second bout (0.90 ± 0.90), which impaired high intensity running ability but did not increase physiological strain. Changing the type of contact during the match simulation subtly altered both the internal and external load on participants. These findings indicate that tackle training apparatus should be considered regarding the outcome of a training session.
    • A reliable testing battery for assessing physical qualities of elite academy rugby league players

      Dobbin, Nicholas; Hunwicks, Richard; Highton, Jamie M.; Twist, Craig (2017-11-14)
      This study assessed the inter-day reliability of a testing battery for the assessment of physical qualities of rugby league players. Fifty players (age 17.1 ± 1.1 years; stature 181.3 ± 6.3 cm; body mass 89.0 ± 11.6 kg) from three Super League academies participated in this study. Tests of countermovement jump performance, 10 and 20 m sprint performance, change of direction, medicine ball throw and a modified Yo-Yo Intermittent Recovery Test Level 1 (prone Yo-Yo IR1) were completed on three separate occasions. Between-day intraclass correlation coefficient, typical error (TE), coefficient of variation (CV) and the smallest worthwhile change (SWC) were calculated to determine the reliability and sensitivity of each measure. Individual tests (except medicine ball throw) were not systematically different between trials (P>0.05), with an inter-day variability that was <10%. In all instances, the TE was larger than the calculated SWC change although variability was less than that typically observed after a training intervention or specific training period (i.e. preseason). Using a magnitude-based inference approach, we present the required change for all performance tests to be 75% confident the change is beneficial. This simple and time efficient testing battery is sufficiently reliable to detect previously observed changes in a range of physical qualities of rugby league players.