Decision-making accuracy in reactive agility: Quantifying the cost of poor decisions
- Authors: Henry, Greg , Dawson, Brian , Lay, Brendan , Young, Warren
- Date: 2013
- Type: Text , Journal article
- Relation: Journal of Strength and Conditioning Research Vol. 27, no. 11 (2013), p. 3190-3196
- Full Text: false
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- Description: Decision-making accuracy and the time cost of incorrect responses was compared between higher- (n = 14) and lowerstandard (n = 14) Australian footballers during reactive agility tasks incorporating feint and nonfeint scenarios. Accuracy was assessed as whether the subject turned in the correct direction to each stimulus. With skill groups pooled, decision accuracy at the first (or only) stimulus (decision time 1) was 94 6 7%, and it decreased to 83 6 20% for the second stimulus (decision time 2; p = 0.01; d = 0.69). However, with skill groups separated, decision accuracy was similar between groups at decision time 1 (higher 95 6 6% vs. lower 92 6 7%; p = 0.6; d = 0.42), somewhat better in the higher-standard group at decision time 2 (88 6 22% vs. 78 6 17%; p = 0.08; d =0.50). But the decrease in accuracy from decision time 1 to 2 was significant in the lower-standard group only (92 6 7% to 78 6 17%; p = 0.02; d = 1.04). However, with skill groups pooled but agility times examined exclusively in trials involving correct or incorrect decisions, incorrect decisions at decision time 1 during feint trials resulted in a shorter agility time (1.73 6 0.24 seconds vs. 2.03 6 0.39 seconds; p = 0.008; d =0.92), whereas agility time was significantly longer in feint (incorrect at decision time 2 only; 2.65 6 0.41 seconds vs. 1.97 6 0.36 seconds; p , 0.001; d = 1.76) and nonfeint trials (1.64 6 0.13 seconds vs. 1.51 6 0.10 seconds; p = 0.001; d = 1.13). Therefore, although decision-making errors typically worsen reactive agility performance, successful anticipation of a feint can produce performance improvements. Furthermore, higher-standard footballers are less susceptible to such feints, perhaps because of superior anticipation. Training to improve decision-making accuracy, particularly involving feint movements, may therefore principally benefit lesser-skilled players and should be practiced regularly. © 2013 National Strength and Conditioning Association.
- Description: C1
Effects of a feint on reactive agility performance
- Authors: Henry, Greg , Dawson, Brian , Lay, Brendan , Young, Warren
- Date: 2012
- Type: Text , Journal article
- Relation: Journal of Sports Sciences Vol. 30, no. 8 (2012), p. 787-795
- Full Text: false
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- Description: This study compared reactive agility between higher-standard (n = 14) and lower-standard (n = 14) Australian footballers using a reactive agility test incorporating a life-size video image of another player changing direction, including and excluding a feint. Mean agility time in the feint trials was 34% (509 ± 243 ms; p < 0.001; effect size 3.06) longer than non-feint trials. In higher-standard players, agility time was shorter than for lower-standard players in both feint (114 ± 140 ms; p = 0.18; effect size 0.52; likely beneficial) and non-feint (32 ± 44 ms; p = 0.22; effect size 0.47; possibly beneficial) trials. Additionally, the inclusion of a feint resulted in movement time increasing over three times more in the lower-standard group (197 ± 91 ms; p = 0.001; effect size 1.07; almost certainly detrimental) than the higher-standard group (62 ± 86 ms; p = 0.23; effect size 0.66; likely detrimental). There were weak correlations between the feint and non-feint trials (r = -0.13-0.14; p > 0.05), suggesting that reactive agility involving a feint is a unique skill. Also, higher-standard players are more agile than their lower-standard peers, whose movement speed deteriorates more as task complexity increases with the inclusion of a feint. These results support the need for specific training in multi-turn reactive agility tasks. © 2012 Copyright Taylor and Francis Group, LLC.
Identifying high risk loading conditions for in-season injury in elite Australian football players
- Authors: Stares, Jordan , Dawson, Brian , Peeling, Peter , Heasman, Jarryd , Rogalski, Brent , Drew, Michael , Colby, Marcus , Dupont, Gregory , Lester, Leanne
- Date: 2018
- Type: Text , Journal article
- Relation: Journal of Science and Medicine in Sport Vol. 21, no. 1 (2018), p. 46-51
- Full Text: false
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- Description: Objectives To examine different timeframes for calculating acute to chronic workload ratio (ACWR) and whether this variable is associated with intrinsic injury risk in elite Australian football players. Design Prospective cohort study. Methods Internal (session rating of perceived exertion: sRPE) and external (GPS distance and sprint distance) workload and injury data were collected from 70 players from one AFL club over 4 seasons. Various acute (1–2 weeks) and chronic (3–8 weeks) timeframes were used to calculate ACWRs: these and chronic load categories were then analysed to determine the injury risk in the subsequent month. Poisson regression with robust errors within a generalised estimating equation were utilised to determine incidence rate ratios (IRR). Results Altering acute and/or chronic timeframes did not improve the ability to detect high injury risk conditions above the commonly used 1:4 week ACWR. Twenty-seven ACWR/chronic load combinations were found to be “high risk conditions” (IRR > 1, p < 0.05) for injury within 7 days. Most (93%) of these conditions occurred when chronic load was low or very low and ACWR was either low (<0.6) or high (>1.5). Once a high injury risk condition was entered, the elevated risk persisted for up to 28 days. Conclusions Injury risk was greatest when chronic load was low and ACWR was either low or high. This heightened risk remained for up to 4 weeks. There was no improvement in the ability to identify high injury risk situations by altering acute or chronic time periods from 1:4 weeks.