TY - JOUR PY - 2019// TI - Modelling the relationships between volume, intensity and injury-risk in professional rugby league players JO - Journal of science and medicine in sport A1 - Cummins, Cloe A1 - Welch, Mitchell A1 - Inkster, Brendan A1 - Cupples, Balin A1 - Weaving, Dan A1 - Jones, Ben A1 - King, Doug A1 - Murphy, Aron SP - 653 EP - 660 VL - 22 IS - 6 N2 - OBJECTIVE: This study aimed to: (a) identify the association between external-workloads and injury-risk in the subsequent week; and (b) understand the effectiveness of workload variables in establishing injury-risk.

DESIGN: Retrospective cohort study.

METHODS: Workload and injury data (soft-tissue) were collected from forty-eight professional male rugby league players. Load variables included duration (min), total distance (m), relative distance (mmin-1), high speed distance ([m]>20kmh-1), very-high speed distance ([m]>25kmh-1), acceleration and deceleration efforts (count) and PlayerLoad (Arbitrary Unit: AU). Cumulative two-, three- and four-weekly loads; Acute:Chronic Workload Ratio (ACWR); Mean-Standard Deviation Workload Ratio (MSWR) and strain values were calculated and divided into three equally-sized bins (low, moderate and high). Generalised Estimating Equations analysed relationships between workload variables and injury probability in the subsequent week.

RESULTS: Injury-risk increased alongside increases in the ACWR for duration, total distance and PlayerLoad. Conversely, injury-risk decreased (Area Under Curve: 0.569-0.585) with increases in the four-weekly duration, total distance, accelerations, decelerations and PlayerLoad. For relative distance, high four-weekly workloads (high: >60mmin-1) demonstrated a positive association with injury-risk, whilst high two-weekly loads (high: >82 mmin-1) were negatively associated.

CONCLUSIONS: A range of external workload metrics and summary statistics demonstrate either positive or negative associations with injury-risk status. Such findings provide the framework for the development of decision-support systems in which external workload metrics (e.g. total or high speed distance) can be uniquely and routinely monitored across a range of summary statistics (i.e. cumulative weekly loads and ACWR) in order to optimise player performance and welfare.

Copyright © 2018 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Language: en

LA - en SN - 1440-2440 UR - http://dx.doi.org/10.1016/j.jsams.2018.11.028 ID - ref1 ER -