ORCID Profile
0000-0002-2745-2969
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Publisher: MDPI AG
Date: 18-12-2020
DOI: 10.3390/JFMK5040099
Abstract: The purpose of this investigation was to determine the effect of a focused versus mixed-methods strength-power training plan on athletes undertaking high volumes of concurrent training. Fourteen junior elite male Australian football players were randomly assigned into either the focused or mixed group. Both training groups undertook a sequenced training intervention consisting of a four-week mesocycle emphasising heavy strength followed by a four-week mesocycle of high velocity emphasis. Training differed between groups by way of the degree of emphasis placed on the targeted attribute in each cycle and occurred during the preseason. Testing occurred pre- and post-training and consisted of the unloaded and loaded (+20 kg) countermovement jump (CMJ). Focused training elicited practical (non-trivial) improvements in flight time to contraction ratio (FT:CT) (g = 0.45, ±90% confidence interval 0.49) underpinned by a small reduction in contraction time (g = −0.46, ±0.45) and a small increase in braking (g = 0.36, ±0.42) and concentric phase mean force (g = 0.22, ±0.39). Conversely, the mixed group demonstrated an unchanged FT:CT (g = −0.13, ±0.56). Similar respective changes occurred in the loaded condition. Preferential improvements in FT:CT occur when a greater focus is placed on a targeted physical quality in a sequenced training plan of junior elite Australian football players during preseason training.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-03-2020
DOI: 10.1519/JSC.0000000000003503
Abstract: Haycraft, JAZ, Kovalchik, S, Pyne, DB, and Robertson, S. Classification of players across the Australian Rules football participation pathway based on physical characteristics. J Strength Cond Res 36(3): 702–709, 2022—This study investigated the utility of physical fitness and movement ability tests to differentiate and classify players into Australian Football League (AFL) participation pathway levels. Players ( n = 293, age 10.9–19.1 years) completed the following tests 5-m, 10-m, and 20-m sprint, AFL planned agility, vertical jump (VJ), running VJ, 20-m multistage fitness test (MSFT), and athletic ability assessment. A multivariate analysis of variance between AFL participation pathway levels was conducted, and a classification tree determined the extent to which players could be allocated to relevant levels. The magnitude of differences between physical fitness and movement ability were level-dependent, with the largest standardized effect size (ES) between Local U12, Local U14, and older levels for most physical fitness tests (ES: −4.64 to 5.02), except the 5-m and 10-m sprint. The 20-m, 5-m, AFL agility, 20-m MSFT, overhead squat, and running VJ (right) contributed to the classification model, with 57% overall accuracy reported (43% under cross-validation). National U16 players were easiest to classify (87%), while National U18 players were most difficult (0%). Physical fitness tests do not seem to differentiate between players after selection into AFL talent pathway levels. Other attributes (i.e., skill, psychological, and sociocultural) should be prioritized over physical fitness and movement attributes by selectors/coaches when considering selection of talented players.
Publisher: SAGE Publications
Date: 19-09-2016
Abstract: This study investigated whether adding a maximal voluntary isometric contraction to developing snowboard and ski cross athletes’ warm-up could reduce start time. A secondary aim was to assess the appropriateness of start performance as a talent identification tool for junior athletes by determining whether differences in time could be explained by participant age and anthropometry. Twenty sub-elite athletes (male: n = 11, female: n = 9, age: 15.0 ± 1.4 years) participated. No differences were found for start time (7.5 m) between maximal voluntary isometric contraction and standardised (no-maximal voluntary isometric contraction) warm-up or gender (maximal voluntary isometric contraction males: 1.36 ± 0.07 s, females: 1.41 ± 0.03 s, no-maximal voluntary isometric contraction males: 1.35 ± 0.01 s, females: 1.38 ± 0.10 s, P 0.05). A strong relationship between body mass and start time to 7.5 m ( r = −0.78, r 2 = 0.61, P 0.05) was observed. Use of maximal voluntary isometric contraction-based warm-ups with developing snowboard cross and ski cross athletes may not be beneficial to improving performance.
Publisher: Elsevier BV
Date: 10-2018
DOI: 10.1016/J.JSAMS.2018.03.008
Abstract: To identify the influence of age-policy changes on the relative age effect (RAE) across the Australian Football League (AFL) talent pathway. Retrospective cross-sectional analysis of junior AFL players attending the National Draft (National), State, and State Under 16s (U16) combines between 1999-2016. Birth-date data was obtained for players attending the AFL State U16 (n=663, age: 15.9±0.4years), State (n=803, age: 19.1±1.7years), National (n=1111, age: 18.3±0.8years) combines. Corresponding aged-matched Australian general population birth rate data was also collected. A chi-squared analysis comparing birth month distributions found all combine groups differed significantly from the general population (Under 16s: χ Selection bias exists towards older players is present at the AFL's State U16, and is maintained at State and National level combines. Age-policy changes are only partially successful at addressing the RAE at the National level, with alternative strategies also recommended in order to address the RAE across the AFL talent pathways.
Publisher: Springer Science and Business Media LLC
Date: 12-2017
Publisher: Springer Science and Business Media LLC
Date: 21-01-2022
DOI: 10.1007/S12283-021-00365-Y
Abstract: Three-dimensional motion capture systems such as Vicon have been used to validate commercial electronic performance and tracking systems. However, three-dimensional motion capture cannot be used for large capture areas such as a full football pitch due to the need for many fragile cameras to be placed around the capture volume and a lack of suitable depth of field of those cameras. There is a need, therefore, for a hybrid testing solution for commercial electronic performance and tracking systems using highly precise three-dimensional motion capture in a small test area and a computer vision system in other areas to test for full-pitch coverage by the commercial systems. This study aimed to establish the validity of VisionKit computer vision system against three-dimensional motion capture in a stadium environment. Ten participants undertook a series of football-specific movement tasks, including a circuit, small-sided games and a 20 m sprint. There was strong agreement between VisionKit and three-dimensional motion capture across each activity undertaken. The root mean square difference for speed was 0.04 m·s −1 and for position was 0.18 m. VisionKit had strong agreement with the criterion three-dimensional motion capture system three-dimensional motion capture for football-related movements tested in stadium environments. VisionKit can thus be used to establish the concurrent validity of other electronic performance and tracking systems in circumstances where three-dimensional motion capture cannot be used.
Publisher: Public Library of Science (PLoS)
Date: 17-06-2020
Publisher: Human Kinetics
Date: 07-2019
Abstract: Purpose : To establish levels of association between physical fitness and match activity profiles of players in the Australian Football League (AFL) participation pathway. Methods : Players (N = 287, range 10.9–19.1 y) were assessed on 20-m sprint, AFL agility, vertical jump and running vertical jump, 20-m multistage fitness test (MSFT), and Athletic Abilities Assessment. Match activity profiles were obtained from global positioning system measures: relative speed, maximal velocity, and relative high-speed running. Results : Correlational analyses revealed moderate relationships between sprint ( r = .32–.57, P ≤ .05) and jump test scores ( r = .34–.78, P ≤ .05) and match activity profiles in Local U12, Local U14, National U16, and National U18s, except jump tests in National U18s. AFL agility was also moderate to strongly associated in Local U12, Local U14, Local U18, and National U16s ( r = .37–.87, P ≤ .05) and strongly associated with relative speed in Local U18s ( r = .84, P ≤ .05). Match relative speed and high-speed running were moderate to strongly associated with 20-m MSFT in Local U14, Local U18, and National U18s ( r = .41–.95, P ≤ .05) and Athletic Abilities Assessment in Local U12 and Local U18s ( r = .35–.67, P ≤ .05). Match activity profile demands increased between Local U12 and National U16s, then plateaued. Conclusions : Physical fitness relates more strongly to match activity profiles in younger adolescent and national-level players. Recruiters should consider adolescent physical fitness and match activity profiles as dynamic across the AFL participation pathway.
No related grants have been discovered for Jade Haycraft.