The acute effect of maximal voluntary isometric contraction pull on start gate performance of snowboard and ski cross athletes

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, r2 = 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

Combine performance, draft position and playing position are poor predictors of player career outcomes in the Australian Football League

Physical testing-based draft combines are undertaken across various sporting codes to inform talent selection. To determine the explanatory power of the Australian football league (AFL) draft combine, participants drafted between 1999-2016 (n = 1488) were assessed. Testing performance, draft selection order and playing position, AFL matches played, AFL player ranking points and AFL player rating points were collected as career outcomes. Boosted regression tree analysis revealed that position and draft selection order were the most explanatory variables of career outcomes. Linear modelling based on testing results is able to explain 4% of matches played and 3% of in-game performance measures. Each individual combine test explained <2% of the matches played outcome. Draft selection order demonstrated mixed results for career outcomes relative to playing position. For instance, key forwards and draft selection order were observed as a slight negative relationship using the AFL Player Ranking points career outcome measure. These findings indicate that the AFL draft combine is a poor measure for informing talent selection, thus providing minimal utility for the practices investigated in this study

BALL TRACKING IN FOOTBALL

This study outines the evaluation of VICON TRACKER software in tracking a ball in a large test area. A 22 camera VICON system and VICON Tracker software was used to track a soccer ball both indoor (22 m x 12 m) and outdoor (22 m x 28 m). Different ball marker setups were evaluated for accuracy and percentage data capture manipulating the number and type of reflective markers, as well as software settings, ands whether the system identified the centre of the ball. TRACKER achieved greater than 90% data capture percentage using the half dome markers or nine flat marker setups. Importantly a pre-test setup of the ball object and a 200 Hz (as opposed to 100 Hz) sample rate was needed. The ball centre was also captured by the software. Future work will examine if this system can perform in larger spaces and with multiple players in the area

Physical and Anthropometric Characteristics Do Not Differ According to Birth Year Quartile in High-Level Junior Australian Football Players

The aim of this study was to explore differences in the physical fitness and anthropometric profiles between birth year quartiles of players attending the Australian Football League (AFL) National Draft Combine. Date of birth, anthropometric, 20 m sprint, vertical and running vertical jump, AFL planned agility, and 20 m Multi-Stage Fitness Test (MSFT) data were obtained for players selected to attend the Combine between 1999 and 2019 (n = 1549; Mage = 18.1; SDage = 0.3). The underlying density distributions of the data were visually explored using violin plots overlaid with box and whisker plots. A multivariate analysis of variance (MANOVA) was then used to model the main effect of birth quartile (four levels) on the physical and anthropometric scores. Results showed that physical and anthropometric test scores did not significantly differ according to birth quartile (V = 0.008, F = 0.880, p = 0.631). We conclude that the physical and anthropometric profiles of high-level junior Australian Football players were similar according to birth year quartile across the modeled period. Therefore, how players utilize their physical and anthropometric attributes during game-play via contextualized, representative assessments, such as small-sided games, should be considered when examining potential causes of a RAE

Physical characteristics of players within the Australian Football League participation pathways: a systematic review

Background Australian football (AF) players require endurance, strength, speed, and agility to be successful. Tests assessing physical characteristics are commonly used for talent identification; however, their ability to differentiate between players across the Australian Football League’s (AFL) participation pathway remains unclear. The objective of this review was to quantify the physical characteristics of male AF players across the AFL participation pathway. Methods A search of databases was undertaken. Studies examining tests of physical performance were included, with 27 meeting the inclusion/exclusion criteria. Study appraisal was conducted using a checklist of selection criteria. Results The 20-m sprint time was the most reported test, followed by vertical jump (VJ), AFL planned agility, and 20-m multi-stage fitness test (MSFT). The fastest times for 20-m sprint were for Elite AFL players (range 2.94–3.13 s), with local-level players the slowest (3.22–4.06 s). State Junior Under (U) 18s (58–66 cm) had higher jumps than senior players, with the lowest jumps reported for Local U10s (mean 31 cm). No elite-level data were reported for the AFL planned agility or 20-m MSFT. AFL planned agility times were only reported for talent pathway levels, with large performance variability evident across all levels (8.17–9.12 s). Only mean 20-m MSFT scores were reported from Local U10s to National Draft Camp (6.10–13.50 shuttles). Conclusions Talent pathway players exhibit similar mean test scores irrespective of the physical test, with the exception of 20-m sprint and VJ. Physical tests can discriminate between local participation level players but are less useful within the AFL talent pathway

Mixed versus Focused Resistance Training during an Australian Football Pre-Season

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, &plusmn;90% confidence interval 0.49) underpinned by a small reduction in contraction time (g = &minus;0.46, &plusmn;0.45) and a small increase in braking (g = 0.36, &plusmn;0.42) and concentric phase mean force (g = 0.22, &plusmn;0.39). Conversely, the mixed group demonstrated an unchanged FT:CT (g = &minus;0.13, &plusmn;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

Challenges and considerations in determining the quality of electronic performance & tracking systems for team sports

Electronic performance & tracking systems (EPTS) are commonly used to track the location and velocity of athletes in many team sports. A range of associated applications using the derived data exist, such as assessment of athlete characteristics, informing training design, assisting match adjudication and providing fan insights for broadcast. Consequently the quality of such systems is of importance to a range of stakeholders. The influence of both systematic and methodological factors such as hardware, software settings, sample rate and filtering on this resulting quality is non-trivial. Highlighting these allows for the user to understand their strengths and limitations in various decision-making processes, as well as identify areas for research and development. In this paper, a number of challenges and considerations relating to the determination of EPTS validity for team sport are outlined and discussed. The aim of this paper is to draw attention of these factors to both researchers and practitioners looking to inform their decision-making in the EPTS area. Addressing some of the posited considerations in future work may represent best practice; others may require further investigation, have multiple potential solutions or currently be intractable

Challenges and considerations in determining the quality of electronic performance & tracking systems for team sports

Electronic performance &amp; tracking systems (EPTS) are commonly used to track the location and velocity of athletes in many team sports. A range of associated applications using the derived data exist, such as assessment of athlete characteristics, informing training design, assisting match adjudication and providing fan insights for broadcast. Consequently the quality of such systems is of importance to a range of stakeholders. The influence of both systematic and methodological factors such as hardware, software settings, sample rate and filtering on this resulting quality is non-trivial. Highlighting these allows for the user to understand their strengths and limitations in various decision-making processes, as well as identify areas for research and development. In this paper, a number of challenges and considerations relating to the determination of EPTS validity for team sport are outlined and discussed. The aim of this paper is to draw attention of these factors to both researchers and practitioners looking to inform their decision-making in the EPTS area. Addressing some of the posited considerations in future work may represent best practice; others may require further investigation, have multiple potential solutions or currently be intractable