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
- Reviewed:
- 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.
Validity of a reactive agility test for Australian football
- Authors: Henry, Greg , Dawson, Brian , Lay, Brendan , Young, Warren
- Date: 2011
- Type: Text , Journal article
- Relation: International Journal of Sports Physiology and Performance Vol. 6, no. 4 (2011), p. 534-545
- Full Text: false
- Reviewed:
- Description: Purpose: To study the validity of a video-based reactive agility test in Australian footballers. Methods: 15 higher performance, 15 lower performance, and 12 nonfootballers completed a light-based reactive agility test (LRAT), a video-based reactive agility test (VRAT), and a planned test (PLAN). Results: With skill groups pooled, agility time in PLAN (1346 ± 66 ms) was significantly faster (P = .001) than both reactive tests (VRAT = 1550 ± 102 ms; LRAT = 1572 ± 97 ms). In addition, decision time was significantly faster (P = .001; d = 0.8) in LRAT (278 ± 36 ms) than VRAT (311 ± 47 ms). The correlation in agility time between the two reactive tests (r = .75) was higher than between the planned and reactive tests (r = .41-.68). Higher performance players had faster agility and movement times on VRAT (agility, 130 ± 24 ms, d = 1.27, P = .004; movement, 69 ± 73 ms, d = 0.88, P = .1) and LRAT (agility, 95 ± 86 ms, d = 0.99, P = .08; movement, 79 ± 74 ms; d = 0.9; P = .08) than the nonfootballers. In addition, higher (55 ± 39 ms, d = 0.87, P = .05) and lower (40 ± 57 ms, d = 0.74, P = .18) performance groups exhibited somewhat faster agility time than nonfootballers on PLAN. Furthermore, higher performance players were somewhat faster than lower performance for agility time on the VRAT (63 ± 85 ms, d = 0.82, P = .16) and decision time on the LRAT (20 ± 39 ms, d = 0.66, P = .21), but there was little difference in PLAN agility time between these groups (15 ± 150 ms, d = 0.24, P = .8). Conclusions: Differences in decision-making speed indicate that the sport-specific nature of the VRAT is not duplicated by a light-based stimulus. In addition, the VRAT is somewhat better able to discriminate different groups of Australian footballers than the LRAT. Collectively, this indicates that a video-based test is a more valid assessment tool for examining agility in Australian footballers. © 2011 Human Kinetics, Inc.
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
- Reviewed:
- 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
Relationships between reactive agility movement time and unilateral vertical, horizontal, and lateral jumps
- Authors: Henry, Greg , Dawson, Brian , Lay, Brendan , Young, Warren
- Date: 2016
- Type: Text , Journal article
- Relation: Journal of Strength and Conditioning Research Vol. 30, no. 9 (2016), p. 2514-2521
- Full Text:
- Reviewed:
- Description: Henry, GJ, Dawson, B, Lay, BS, and Young, WB. Relationships between reactive agility movement time and unilateral vertical, horizontal, and lateral jumps. J Strength Cond Res 30(9): 2514-2521, 2016 - This study compared reactive agility movement time and unilateral (vertical, horizontal, and lateral) jump performance and kinetics between dominant and nondominant legs in Australian rules footballers (n 31) to investigate the role of leg strength characteristics in reactive agility performance. Jumps involved jumping forward on 1 leg, then for maximum height or horizontal or lateral distance. Agility and movement time components of reactive agility were assessed using a video-based test. Correlations between each of the jumps were strong (r -0.62 to -0.77), but between the jumps and agility movement time the relationships were weak (r -0.25 to -0.33). Dominant leg performance was superior in reactive agility movement time (4.5%; p 0.04), lateral jump distance (3%; p 0.008), and lateral reactive strength index (4.4%; p 0.03) compared with the nondominant leg. However, when the subjects were divided into faster and slower performers (based on their agility movement times) the movement time was significantly quicker in the faster group (n 15; 12%; p < 0.001), but no differences in jump performance or kinetics were observed. Therefore, although the capacity for jumps to predict agility performance seems limited, factors involved in producing superior lateral jump performance in the dominant leg may also be associated with advantages in agility performance in that leg. However, because reactive strength as measured by unilateral jumps seems to play a limited role in reactive agility performance and other factors such as skill, balance, and coordination, and also cognitive and decision-making factors, are likely to be more important. © 2013 National Strength and Conditioning Association.