Peak Movement and Technical Demands of Professional Australian Football Competition.

ABSTRACT: Johnston, RD, Murray, NB, Austin, DJ, and Duthie, G. Peak movement and technical demands of professional Australian football competition. J Strength Cond Res 35(10): 2818-2823, 2021-The aim of this study was to determine the average peak movement and technical demands of professional Australian football (AF) across a number of period durations using an observational cohort design. This information will be able to guide duration-specific intensities for training drills. Microtechnology and technical performance data were recorded across 22 games of the 2017 AF League season. The peak 1-, 3-, 5-, 7-, and 10-minute rolling periods were determined from each game for each player for each frequency of skill involvements. Average speed (m·min-1) and accelerometer load (PlayerLoad; PL·min-1) were used as measures of physical output, and any disposal of the football or tackle was used as a technical involvement. Linear mixed models and Cohen's effect size (ES) statistic were used to determine the impact technical involvements had on movement profiles. There were substantial reductions in average speed across each duration as the number of technical involvements increased, other than for the 10-minute period. The reductions in speed were greatest during the 1-minute period for 1 (ES = -0.59 ± 0.13), 2 (ES = -1.96 ± 0.17), and 3 (ES = -2.39 ± 0.27) involvements. Similarly, less pronounced reductions were seen for accelerometer load, other than during the 7- and 10-minute periods where there were small to moderate increases in load for periods with technical involvements. Players may have to perform as many as 3 technical involvements a minute while covering 150-160 m·min-1. This information provides coaches with the peak speed, accelerometer load, and technical demands of competition. There are reductions in movement profiles as the number of technical involvements increases.

Phases of match-play in professional Australian Football: Distribution of physical and technical performance.

The current study aimed to describe the distribution of physical and technical performance during the different phases of play in professional Australian Football. The phases of play (offence, defence, contested play, umpire stoppages, set shots and goal resets) were manually coded from video footage for a single team competing in 18 matches in the Australian Football League. Measures of physical performance including total distance (m), average speed (m · min-1), low-speed running (LSR, <14.4 km h-1), high-speed running (HSR, >14.4 km h-1), accelerations (2.78 m · s-2) and decelerations (-2.78 m · s-2) were derived from each phase of play via global positioning system (GPS) devices. Technical skill data including tackles, handballs and kicks were obtained from a commercial statistics provider and derived from each phase of play. Linear mixed-effects models and effect sizes were used to assess and reflect the differences in physical and technical performance between the six phases of play. Activity and recovery cycles, defined as periods where the ball was in or out of play were also described using mean and 95% confidence intervals. The analysis showed that several similarities existed between offence and defence for physical performance metrics. Contested play involved the highest total distance, LSR, accelerations, decelerations and tackles compared to all other phases. Offence and defence involved the highest average speed and HSR running distances. Handballs and kicks were highest during offence, while tackles were highest during contested play, followed by defence. Activity and recovery cycles involved mean durations of ~110 and ~39 s and average speeds of ~160 and ~84 m · min-1, respectively. The integration of video, GPS and technical skill data can be used to investigate specific phases of Australian Football match-play and subsequently guide match analysis and training design.

Applied Sport Science of Australian Football: A Systematic Review.

BACKGROUND: In recent years, there has been a large expansion in literature pertaining to the game of Australian football (AF). Furthermore, there have been a number of rule changes that are likely to have changed the demands of the game. Based on these advances and changes, it seemed important to conduct a review assessing the scientific literature surrounding the sport. OBJECTIVE: The review evaluates the match demands of AF, the qualities required for success, and the impact training and competition have on adaptation, injury and fatigue. METHODS: A systematic search of PubMed, CINAHL, SPORTDiscus, Web of Science and Scopus for AF literature was conducted; studies investigating match demands, physical qualities, training practices and injury were included. Weighted means and standard deviations were calculated for match demands and physical and anthropometric profiles across playing standards. RESULTS: A total of 1830 articles were retrieved in the initial search, with 888 removed as duplicates, 626 removed for being non-relevant and a further 152 removed for being AF papers but not relevant to the review. As such, 164 AF papers were included in the review. Due to the intermittent high-intensity nature of match-play, players need a wide range of physical and technical qualities to excel, with speed, aerobic fitness, reactive agility and well-developed lean mass being central to success. Training for AF at the elite level is associated with high workloads, with players engaging in numerous training modalities; even altitude and heat training camps have been utilised by Australian Football League (AFL) teams to further augment fitness improvements. While high chronic workloads can be tolerated and are needed for improving physical qualities, careful planning and monitoring of internal and external workloads is required to minimise sharp spikes in load that are associated with injury. CONCLUSIONS: There is a complex interaction between numerous contextual factors that influence the match demands that are discussed in this review. Whilst players must have the physical capacities to cope with the intense physical demands of AF matches, the successful execution of technical skills during match-play is central to success. To develop these skills and attributes, specific and carefully planned and monitored training must be performed over a number of years.

Differences in Physical Capacity Between Junior and Senior Australian Footballers.

Kelly, SJ, Watsford, ML, Austin, DJ, Spurrs, RW, Pine, MJ, and Rennie, MJ. Differences in physical capacity between junior and senior Australian footballers. J Strength Cond Res 31(11): 3059-3066, 2017-The purpose of this study was to profile and compare anthropometric and physical capacities within elite junior and senior Australian football (AF) players of various chronological ages and stages of athletic development. Seventy-nine players, including junior and senior AF players from one professional club, were profiled using 11 assessments. Junior players were divided into 2 groups based on chronological age (under 16 and 18 years) and senior players according to years since drafted to a professional AF team (1-2 years, 3-7 years, and 8+ years). Parametric data were assessed using a 1-way analysis of variance (ANOVA), whereas nonparametric data were assessed using a Kruskal-Wallis ANOVA. The magnitude difference between players was measured using the Hopkins' effect size (ES). Significant differences were evident between under-16 players and all senior player groups for anthropometric (p = 0.001-0.019/ES = 1.25-2.13), absolute strength (p = 0.001-0.01/ES = 1.82-4.46), and relative strength (p = 0.001-0.027/ES = 0.84-3.55). The under-18 players displayed significantly lower absolute strength (p = 0.001-0.012/ES = 1.82-3.79) and relative strength (p = 0.001-0.027/ES = 0.85-4.00) compared with the 3-7 and 8+ players. Significant differences were evident between the under-16 players and senior player groups for explosive jumping and throwing tests (p = 0.001-0.017/ES = 1.03-2.99). Minimal differences were evident between all player groups for running assessments; however, the under-16 players were significantly slower compared with the 8+ players for the 3-km time trial (p < 0.02/ES = 1.31), whereas both junior player groups covered significantly less distance during the Yo-Yo IR2 (p < 0.02/ES = 1.19 and 1.60). Results of this study display a significant deficit in strength between junior and senior AF players.

Movement Profiles, Match Events, and Performance in Australian Football.

Johnston, RJ, Watsford, ML, Austin, D, Pine, MJ, and Spurrs, RW. Movement profiles, match events, and performance in Australian football. J Strength Cond Res 30(8): 2129-2137, 2016-This study examined the relationship between movement demands, match events, and match performance in professional Australian football. Data were collected from 19 players using global positioning system units during 2 Australian Football League seasons. A range of movement demands and instantaneous power measures were collected. The players were divided into high-caliber (HC, ≥17/20) and low-caliber (LC, ≤8/20) groups based on the rating score by their coaches. A Mann-Whitney U-test, independent samples t-test, and effect sizes were used to determine whether any differences existed between the 2 groups. The HC group had a significantly higher match duration (7.2%), higher total distance (9.6%), and covered more distance and spent more time high-speed running per minute (12.7 and 11.9%). Although not significant, the effect sizes revealed that the HC group tended to have a higher mean metabolic power output (2.6%) and spent more time at the high power zone (7.9%). For the match event data, the HC group had significantly more involvements with the football. The results demonstrated the higher physical demands placed on the HC group. The findings suggest that analyzing instantaneous power measures can provide valuable information about the physical demands placed on team sport athletes to coaches and conditioning staff.

Movement Demands and Metabolic Power Comparisons Between Elite and Subelite Australian Footballers.

This study examined the differences in movement demands and metabolic power output of elite and subelite Australian football (AF) players and quantified the movement profiles of a subelite AF competition. Movement variables were collected from AF players using Global Positioning System devices over 2 AF League (elite) and North East Australian Football League (NEAFL, subelite) seasons. A total of 500 files were collected from 37 elite and subelite nomadic AF players. NEAFL players covered 13,547 m at an average speed of 124.5 m·min(-1). Elite players performed more high-speed running (5.7-6.3%) and high acceleration and deceleration efforts (1.9-14.7%, p ≤ 0.05). The elite players had a higher mean metabolic power output (3.2%) and time spent at the very high power zone (15.9%, p ≤ 0.05). In contrast, elite players recorded a lower total match duration than the subelite players (4%, p ≤ 0.05). The contrasting amount of high-intensity activities performed by the 2 groups demonstrates the need to alter the training programs of subelite players to ensure they are capable of meeting the demands of elite football. The differences in match duration suggest that reducing subelite players' match time through increasing their rotations would assist the replication of movement profiles of elite players.

An Examination of the Relationship Between Movement Demands and Rating of Perceived Exertion in Australian Footballers.

This study aimed to determine whether a relationship existed between movement demands, match events, and perceptual match load, as determined by rating of perceived exertion (RPE) in professional Australian footballers. The movement variables were collected between 1 and 22 times using global positioning system units from 21 players during the 2011 and 2012 Australian Football League seasons. A range of movement demands and match events were collected to obtain a complete insight into the physical demands and work rates of these athletes. These data were separated into the high-load (HL, ≥9) and low-load (LL, ≤8) RPE groups. A Mann-Whitney U-test, independent samples t-test, and effect sizes were used to determine whether any differences existed between the 2 groups and the size of the difference. The results revealed that the HL groups covered more distance, spent more time, and produced more efforts at the high deceleration zone (2.4-6.7%). Further, the HL group had more possessions and disposals of the football than the LL group (9.2-29.6%). The findings have highlighted the importance of monitoring accelerations, decelerations, and instantaneous power outputs to obtain a comprehensive insight into the physical demands placed on team sport athletes. Furthermore, the results demonstrate that training sessions should involve a focus on drills that are composed of both skill development and physical stimulus element.

Professional rugby league positional match-play analysis through the use of global positioning system.

The purpose of this study was to quantify the movement demands of all 9 individual playing positions in professional rugby league. The movement demands of 135 professional rugby league players were recorded during 28 National Rugby League games in 2011, using a nondifferential 5 Hz global positioning system. The mean total distances covered in a game for fullback, wing, center, five-eight, halfback, hooker, lock, back row, and prop players were 7,760, 7,457, 7,301, 8,402, 8,500, 6,988, 5,481, 6,936, and 4,597 m, respectively. The average occurrence of high-intensity runs per match was 42, 35, 34, 86, 120, 74, 52, 26, and 18 for fullback, wing, center, five-eight, halfback, hooker, lock, back row, and prop players, respectively. The average distance traveled greater than 18 km·h-1 for fullback were 17 ± 2 m, wing 18 ± 2 m, center 18 ± 3 m, five-eight 16 ± 3 m, and halfback 17 ± 4 m. The average distance and range traveled greater than 18 km·h for hooker were 14 ± 3 m, lock 16 ± 2 m, back row 18 ± 3 m, and prop 16 ± 2 m. The use of global positioning systems has demonstrated plausibility to eliminate the use of grouping of positions in rugby league and for coaches to make specific training protocols for each position. Given the differences in movement demands of all 9 positions in rugby league, some positions would lack specificity to their positional requirements if using collective grouping for planning of training regimens.

Positional differences in professional rugby league match play through the use of global positioning systems.

The current use of tracking technology in the form of global positioning systems allows for a greater analysis of locomotor activities occurring in games and a larger volume of games when compared with time-motion analysis. Therefore, the aim of this study is to be the first to analyze the physiological demands of forwards and backs throughout the entirety of an Australian professional rugby league season. The movement patterns of 185 players from a professional rugby league club were recorded during 28 National Rugby League games played in Australia during the 2010 season. The players were clustered into 2 positional groups, backs and forwards. Maximum match-play time recorded was 99 minutes and 50 seconds in a semifinal game recorded for both a forward and back. The mean total distances covered in a game for forwards and backs were 5,964 ± 696 and 7,628 ± 744 m, respectively (p < 0.05). The maximum distance recorded by a forward was 10,511 and 10,359 m for a back. The average number of occurrences in high-intensity running (>18 km·h(-1)) was 23 ± 4 and for forwards and significantly higher backs with 35 ± 8 (p < 0.05). The maximum work rate in a 10-minute block of match play was 115 and 120 m·min(-1) of play for forwards and backs, respectively. Understanding the physiological demands of a sport is important for coaches to deliver athletes optimal training programs that elicit appropriate and specific physiological adaptation. The differences in locomotor activities, which occur between positions, need to be accounted for when developing training programs.

Reliability and sensitivity of a repeated high-intensity exercise performance test for rugby league and rugby union.

The purpose of this study was to examine the reliability and sensitivity of 3 ecologically valid repeated high-intensity exercise (RHIE) tests for professional rugby league (RL) and rugby union (RU) players. A further purpose was to investigate the relationship between RHIE performance and measures of speed (20-m sprint) and high-intensity intermittent running ability (yo-yo intermittent recovery test). Thirty-six RU and RL players were separated into 3 equal groups based on playing position: backs, RL forwards and RU forwards. Test-retest reliability was assessed by comparing total sprint time over 9 sprints during 2 identical testing sessions. The intraclass correlation coefficients (ICCs) for total sprint time were moderate to high (0.82, 0.97, and 0.94) and coefficient of variation (CV) low (4.2, 1.4, and 0.6%) for the backs, RL forwards, and RU forwards tests, respectively. However, sprint performance decrement scores were poorer, with ICC and CV of 0.78, 0.86, and 0.88 and 49.5, 48.2, and 35.8% for the backs, RL forwards, and RU forwards, respectively. Total sprint times for the backs, RL forwards, and RU forwards decreased over the 3 tests by 0.54, 0.53, and 2.09 seconds, respectively. Changes in RHIE total sprint time were moderately related to changes in 20-m sprint times (T1 to T2, r = 0.63; T2 to T3, r = 0.69; and T1 to T3, r = 0.63; all p < 0.05) but not yo-yo intermittent recovery test performances. This study has shown that the designed RL and RU RHIE tests have moderate to high reliability and produce significant improvements over a training period when total sprint times are compared.

Repeated high-intensity exercise in a professional rugby league.

The primary aim of this study was to identify and describe the frequency and duration of repeated high-intensity exercise (RHIE) bouts in Australian professional rugby league (National Rugby League) and whether these occurred at critical times during a game. Time motion analysis was used during 5 competition matches; 1 player from 3 positional groups (hit-up forward, adjustable, and outside back) was analyzed in each match. The ranges of RHIE bouts for the 3 positional groups were hit-up forwards 9-17, adjustables 2-8, and outside backs 3-7. Hit-up forwards were involved in a significantly greater number of RHIE bouts (p < 0.05) and had the shortest average recovery (376 ± 205 seconds) between RHIE bouts. The single overall maximum durations of RHIE bouts for the hit-up forwards, the adjustables, and the outside backs were 64, 64, and 49 seconds. For all groups, 70% of the total RHIE bouts occurred within 5 minutes prior of a try being scored. The present data show that the nature of RHIE bouts was specific to playing position and occurred frequently at critical times during the game. These results can be used to develop training programs that mimic the 'worst case scenarios' that elite rugby league players are likely to encounter.