Does the recent internal load and strain on players affect match outcome in elite Australian football?
Authors: Andrew M Stewart
Alireza Esmaeili
Brendan Lazarus
George P Elias
Robert J Aughey
Journal: Journal of Science and Medicine in Sport (2016)
Discipline: CLINICAL MEDICINE
Keywords: Elite football; Internal load; Strain.
Affiliations: Institute of Sport, Exercise and Active Living, Victoria University, Australia. Electronic address: ., Institute of Sport, Exercise and Active Living, Victoria University, Australia.

Abstract:  Objectives: To compare recent internal training load and strain of elite Australian football players for match outcome. Design: Case study. Methods: Load was quantified from session rating of perceived exertion (sRPE) for individual players from one team in 141 professional Australian football matches over six seasons, then averaged for players that competed for the team each week. Internal weekly-load and weekly-strain (load×monotony) was compared to recent-load and recent-strain (four-week rolling average) as a marker of training-stress balance for each player against the match outcome. Covariates for relative position of teams in the competition and days between matches were modelled. Differences were standardised (effect size; ES) and interpreted using magnitude based inferences. Results: Weekly-load was likely higher for match wins (ES±90% confidence limits; 0.43±0.27), and when days-break was used as a covariate (0.45±0.27) but only possibly higher with relative ladder position covaried (RLP, 0.29±0.33). There was a possibly greater positive training-stress balance for load in wins (0.31; ±0.38) with db (0.39; ±0.39) and RLP covaried (0.27; ±0.48). There were no clear differences for strain for wins and losses or with either covariate. There was a likely greater positive training-stress balance for strain in wins (0.51; ±0.41) with days-break (0.48; ±0.41) but not RLP covaried. Conclusions: Weekly-load and a positive training-stress balance for strain were the best predictors of match success. The higher weekly-load and training-stress balance for strain highlight the conflict between maintaining the training stimulus and minimising fatigue in Australian football players between matches. 

Retracted: No

PubPeer comments:
 In 2014, Alan Welch presented his work along with Emma Knight to the AIS where they looked into a method of statistics called Magnitude Based Inference (MBI). MBI has never been published in a statistical or mathematical journal but is heavily used by the sports science field. You can view the presentation here https: maths.anu.edu.au files AIS-slides.pdf . After presenting MBI was supposedly discontinued at the AIS after Alan and Emma showed the method to be fundamentally flawed. In 2018 a 538 article was written about MBI uptake within the sports science field. https: fivethirtyeight.com features how-shoddy-statistics-found-a-home-in-sports-research This article notes to further work was done by Kristin Sainani, showing that MBI has numerous issues. She gives reproducible mathematics to show this. https: www.ncbi.nlm.nih.gov pubmed 29683920 In 2019 there was an article written in The Age talking about how still MBI is being used. https: www.smh.com.au national cold-water-poured-on-scientific-studies-based-on-statistical-cult-20191108-p538t6.html While this was published in 2016, it should be noted that this is still well after Alan Welches presentation to the AIS which led to it being banned as a method at the AIS. Unfortunately Andrew Stewarts comments in the age article are misleading, you can t change a method after the fact and that makes previous findings valid. No, if there ever is a change to MBI this study should be redone. ,