@article{ref1,
title="Playerload variables are sensitive to changes in direction and not related to collision workloads in rugby league match-play",
journal="International journal of sports physiology and performance",
year="2018",
author="Hulin, Billy T. and Gabbett, Tim J. and Johnston, Rich D. and Jenkins, David G.",
volume="13",
number="9",
pages="1136-1142",
abstract="PURPOSE: Determine: 1) how change of direction (COD) workloads influence PlayerLoad variables when controlling total distance covered, and 2) relationships among collision workloads and PlayerLoad variables during rugby league match-play. <br><br>METHODS: Participants completed 3 protocols (crossover design) consisting of 10 repetitions of a 60 m effort in 15 s. The difference between each protocol was the COD demands required to complete 1 repetition; no COD (SL), 1 x 180º COD (1COD), or 3 x 180º COD (3COD). During rugby league matches, relationships among collision workloads, tri-axial PlayerLoad (PLVM), anterior-posterior + medio-lateral PlayerLoad (PL2D), and PLVM accumulated at locomotor velocities below 2 m.sec<sup>-1</sup>(i.e. PLSLOW) were examined using Pearson correlations (r) with coefficients of determination (R<sup>2</sup>). <br><br>RESULTS: Comparing 3COD to SL drills: PLVM.min<sup>-1</sup>(d = 1.50 ± 0.49, large, likelihood = 100%, almost certainly), PL2D.min<sup>-1</sup>(d = 1.38 ± 0.53, large, likelihood = 100%, almost certainly), and PLSLOW.min<sup>-1</sup>(d = 1.69 ± 0.40, large, likelihood = 100%, almost certainly) were greater. Collisions.min<sup>-1</sup>demonstrated a distinct (i.e. R<sup>2</sup><0.50) relationship from PLVM.min<sup>-1</sup>(R<sup>2</sup>= 0.30, r = 0.55), and PL2D.min<sup>-1</sup>(R<sup>2</sup>= 0.37, r = 0.61). Total distance.min<sup>1</sup>demonstrated a very large relationship with PLVM.min<sup>-1</sup>(R<sup>2</sup>= 0.62, r = 0.79), and PL2D.min<sup>-1</sup>(R<sup>2</sup>= 0.57, r = 0.76). <br><br>CONCLUSIONS: PlayerLoad variables demonstrate: 1) large increases as COD demands intensify, 2) separate relationships from collision workloads, and 3) moderate to very large relationships with total distance during match-play. PlayerLoad variables should be used with caution to measure collision workloads in team sport.<p /> <p>Language: en</p>",
language="en",
issn="1555-0265",
doi="10.1123/ijspp.2017-0557",
url="http://dx.doi.org/10.1123/ijspp.2017-0557"
}