The Reliability of Neuromuscular and Perceptual Measures Used to Profile Recovery, and the Time-Course of such Responses following Academy Rugby League Match-Play.

Hendrickus G J Aben,Mark Russell,Carlton B Cooke,Danielle Davis,Samuel P Hills,Darren Higgins,Ben Jones

doi:10.3390/sports8050073

Abstract

In professional academy rugby league (RL) players, this two-part study examined; (A) the within- and between-day reliability of isometric mid-thigh pulls (IMTP), countermovement jumps (CMJ), and a wellness questionnaire (n = 11), and (B) profiled the responses with acceptable reliability (no between-trial differences and between-day coefficient of variation (CV) ≤10% and intraclass correlation coefficient (ICC) ≥0.8) for 120 h (baseline: −3, +24, +48, +72, +96, +120 h) following RL match-play (n = 10). In part A, force at 200, and 250 ms, and peak force (PF) demonstrated acceptable within- (CV%: 3.67–8.41%, ICC: 0.89–0.93) and between-day (CV%: 4.34–8.62%, ICC: 0.87–0.92) reliability for IMTP. Most CMJ variables demonstrated acceptable within-day reliability (CV%: 3.03–7.34%, ICC: 0.82–0.98), but only six (i.e., flight-time, PF, peak power (PP), relative PP, velocity at take-off (VTO), jump-height (JH)) showed acceptable between-day reliability (CV%: 2.56–6.79%, ICC: 0.83–0.91). Only total wellness demonstrated acceptable between-day reliability (CV%: 7.05%, ICC: 0.90) from the questionnaire. In part B, reductions of 4.75% and 9.23% (vs. baseline; 2.54 m∙s−1; 0.33 m) occurred at +24 h for CMJ VTO, and JH, respectively. Acceptable reliability was observed in some, but not all, variables and the magnitude and time-course of post-match responses were test and variable specific. Practitioners should therefore be mindful of the influence that the choice of recovery monitoring tool may have upon the practical interpretation of the data.

Highlights

Rugby league is a team sport characterised by high-intensity activities such as high-speed (≥5.5 m·s−1 ) running and sprinting (≥7.0 m·s−1 ) actions that are interspersed with contact efforts, and low-intensity activities such as standing, walking and Sports 2020, 8, 73; doi:10.3390/sports8050073 www.mdpi.com/journal/sportsSports 2020, 8, 73 jogging [1,2,3]
Match-play did not elicit significant post hoc differences for the majority of variables analysed, a large ES was observed in the post-match period for most variables (i.e., F200, F250 and peak force (PF) of the isometric mid-thigh pulls (IMTP), FT, peak power (PP) of the countermovement jumps (CMJ) and in the total wellness score) when compared to baseline measures
These results indicate that the magnitude and time-course of post-match responses may differ depending on the test and individual variables used

Summary

Introduction

Rugby league is a team sport characterised by high-intensity activities such as high-speed (≥5.5 m·s−1 ) running and sprinting (≥7.0 m·s−1 ) actions that are interspersed with contact efforts (i.e., collisions, wrestling and grappling), and low-intensity activities such as standing, walking and Sports 2020, 8, 73; doi:10.3390/sports8050073 www.mdpi.com/journal/sportsSports 2020, 8, 73 jogging [1,2,3]. Up to 120 h may be required to facilitate full post-match recovery [8], most observations from adult players have reported durations of 48–72 h [7,11] when profiling the restoration of neuromuscular, biochemical or endocrine, and/or perceptual responses [12] These inconsistencies may reflect methodological differences between studies, such as the reliability of the specific variables being examined [13], between-study differences in match-play demands, as well as discrepancies in training regimes [8,14] and recovery strategies [7,11] implemented in the post-match period; all of which are known to modulate post-match recovery [12]. Literature reporting the reliability of the various recovery markers used in collision-sports players is limited, in both senior [15], and academy [13]

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Discussion

Conclusion