The Acute Effects of Ball Pressure on Anticipation Timing Following a Series of Purposeful Headers in Adult Football (Soccer) Players.

The purpose of this study is to investigate the acute effects of ball pressure on anticipation timing following a series of purposeful headers in adult football (soccer) players. There is evidence to suggest acute neurophysiological changes to the brain following purposeful heading; this may lead to altered anticipation timing as a result, potentially having future safety implications for players. A repeated measures crossover design was used. Seventeen participants aged between 20 and 30 years performed (i) 20 rotational headers with a lower-pressure match ball (58.6 kPa; 8.5 psi), (ii) 20 rotational headers with a higher-pressure match ball (103.4 kPa; 15 psi), or (iii) 20 non-headers (kicks) as a control each on separate days. The effect of ball pressure on anticipation timing accuracy, measured as absolute, constant, and variable errors, was assessed before and immediately after each intervention session using an anticipation timing task. Differences between group means were compared using repeated measures ANOVA and linear mixed effects models, with p-values of <0.05 considered statistically significant. No significant differences in anticipation timing accuracy across interventions were detected between control, occluded, and non-occluded trials. This finding differs from the previous literature regarding the measurable, acute effects of purposeful heading. The anticipation timing task may lack sensitivity for detecting the effects of repeated heading on brain function.

The incidence and characteristics of heading in the 2019 FIFA Women's World Cup™.

INTRODUCTION: To quantify the incidence and characteristics of purposeful heading and other head impacts in professional women's football at the 2019 FIFA Women's World Cup™. METHODS: This cross-sectional cohort study analysed purposeful headers (uncontested and contested) and their characteristics (e.g. playing position, match situation, field location, and distance ball travelled), and other head impact events using video analysis. Total headers and head impact events, and incidence rate (IR) per 1000 match-hours were calculated for countries, positions, and other characteristics, such as location on the pitch. RESULTS: Purposeful headers accounted for 76% of all coded events (uncontested: 71%; contested: 29%), followed by attempted headers (21%), unintentional ball-head impacts (2%), and other head impacts (1%). Headers ranged from 0 to 22 per player, per match with a mean of 4.8 [±1.2]. Of all field positions, centrebacks had the highest heading rates and wingers the lowest. Strikers performed significantly more contested headers than any other position, and significantly less uncontested headers. Most headers occurred in the middle third (48%), from free game play (72%) and from long balls (>20 m) (68%). CONCLUSION: The findings of this study could assist the development of player heading risk profiles, sex-specific heading guidelines, and coaching practices.

Factors Affecting Physical and Technical Performance in Australian Football.

ABSTRACT: Wing, C, Hart, NH, Ma'ayah, F, and Nosaka, K. Factors affecting physical and technical performance in Australian football. J Strength Cond Res 37(9): 1844-1851, 2023-This study assessed player (i.e., lower-body strength and power and aerobic fitness) and environmental (e.g., venue) factors and their effects on the physical (e.g., distance) and technical (e.g., kicks) demands of Australian football (AF). Relative distance, high-speed running (HSR), and acceleration efforts for 19 matches by 33 players in a West AF League team were analyzed from global positioning system data split into periods of successful offense and defense and maximum ball in play (BiP) periods, as well as technical actions. Lower-body strength and power, and aerobic fitness were evaluated using a one-repetition trap-bar deadlift, countermovement jump, 2-km time trial, and Yo-Yo intermittent fitness test, respectively. In matches played at home, distance (p < 0.001, ES = 0.39) and HSR (p < 0.001, ES = 0.34) were significantly reduced during successful defense. In addition, tackle rate was significantly increased (p = 0.003, ES = 0.16) during successful defense when playing at home. Trap-bar deadlift relative to mass significantly increased relative distance (p = 0.004, ES = 0.51) and HSR (p = 0.029, ES = 0.40) in successful offense. In successful defense, superior time trial performance significantly increased relative distance (p < 0.001, ES = 0.58), HSR (p < 0.001, ES = 0.59), and acceleration efforts (p = 0.017, ES = 0.44), while relative distance (p < 0.001, ES = 0.62) and HSR (p = 0.004, ES = 0.52) were also increased during maximum BiP periods. The results demonstrate that player factors have the largest effect on the physical and technical performance of AF players.

Replicating Maximum Periods of Play in Australian Football Matches Through Position-Specific Drills.

ABSTRACT: Wing, C, Hart, NH, Ma'ayah, F, and Nosaka, K. Replicating maximum periods of play in Australian football matches through position-specific drills. J Strength Cond Res 37(8): 1628-1633, 2023-This study evaluated whether a position-specific drill replicates the running intensities of maximum ball in play (BiP) phases in competitive matches of Australian football (AF). Match data were collected on 32 AF players across 3 seasons (2019, 2020, 2021), with training session data collected from the same players across the 2021 season. Three position-specific training drills were created for defense, offense, and combination (defense and offense combined). Running intensities were compared between maximum BiP periods (e.g., periods with the highest metric per minute) from competitive matches and position-specific training drills, as well as between the 3 position-specific training drills using linear mixed models. The significance level was set at p < 0.05. Measures of distance (offense: 44.4 m·minute -1 , defense: 83.5 m·minute -1 , combination: 50.4 m·minute -1 ), high-speed running (offense: 76.7 m·minute -1 , defense: 134.6 m·minute -1 , combination: 89.6 m·minute -1 ), very high-speed running (offense: 26.7 m·minute -1 , defense: 56.2 m·minute -1 , combination: 55.0 m·minute -1 ), and high-intensity efforts (offense: 2.3 efforts·minute -1 , defense: 3.0 efforts·minute -1 , combination: 2.8 efforts·minute -1 ), relative to time were greater ( p < 0.001) in all 3 position-specific training drills compared with BiP phases. All measured metrics were significantly ( p < 0.001) greater in the defense drill compared with the offense drill, whereas distance, high-speed running, PlayerLoad, and accelerations were significantly ( p < 0.001) greater when compared with the combination drill. These demonstrate that position-specific training drills that we created replicated or exceeded the running intensities recorded during matches based on maximum BiP periods. Position-specific training drills seem to be an attractive addition to AF players training regimens because it concurrently provides training for physical and technical actions (e.g., handballs).

Effects of High-Intensity Position-Specific Drills on Physical and Technical Skill Performance in Elite Youth Soccer Players.

ABSTRACT: Cuong Le, C, Ma'ayah, F, Nosaka, K, Hiscock, D, and Latella, C. Effects of high-intensity position-specific drills on physical and technical skill performance in elite youth soccer players. J Strength Cond Res 37(5): e332-e340, 2023-Soccer physical preparation has been extensively researched with previous emphasis on high-intensity interval running and small-sided games. However, neither approach considers positional differences. The purpose of this study was to investigate the feasibility and short-term effects of a novel position-specific conditioning training (PSCT) paradigm on physical and technical abilities of young soccer players. Fifteen male Vietnamese professional youth soccer players (16.1 ± 0.4 years, 171.7 ± 4.8 cm, 63.9 ± 3.8 kg) undertook a 3-week control period followed by a 3-week intervention with PSCT drills performed twice per week. Position-specific conditioning training comprised purposely designed drills for attackers, defenders, and wingers, respectively. The intensity and duration were the same for all drills (4 × 4 minutes at ∼90% heart rate maximum [HRmax], separated by a 4-minute recovery at 70% HRmax) but differed in the technical and tactical actions performed. Outcome measures included Yo-Yo intermittent recovery test level 1, repeated sprint ability, 10-m and 30-m sprint time, and the Loughborough Soccer Passing Test for technical skills in a fatigued and nonfatigued state. Position-specific conditioning training drills induced a desirable intensity for effective conditioning purpose (89.0 ± 2.1% HRmax) with low interplayer variability (coefficient of variation = 2.4%). Yo-Yo intermittent recovery test level 1 performance improved ( p < 0.05) after the control (Δ178.7 ± 203.3 m) and intervention (Δ176.0 ± 225.7 m) periods without a difference between. These results confirmed the feasibility of PSCT as a novel high-intensity training approach for soccer players. Improvements in aerobic capacity were noted, despite no effect on other physical and technical measures. PSCT may be suitable for individual training, return-to-play stages of rehabilitation, during off-season, or in academy settings when time is not a constraint.

Impact of Sudden Rule Changes on Player Injuries and Performance: Insights from Australian Football.

This study investigated the effects of reduced quarter time due to COVID-19 pandemic rule changes, on running performance and injuries in Australian Football. Microsensor data for eight matches performed by the same 17 players were compared between the 2019 (standard) and 2020 (COVID-19) seasons using linear and generalised mixed models. Injury rates were assessed in 34 players across the full 2019 season, and 32 players across the full 2020 season. The total distance (ES = 1.28 [0.55 to 2.02]), high-speed (>18 km/h) (ES = 0.44 [-0.24 to 1.12]) and very highspeed (>24 km/h) (ES = 0.27 [-0.41 to 0.94]) distances, PlayerLoad™ (ES = 0.96 [0.25 to 1.67]), high-intensity efforts (ES = 0.48 [-0.20 to 1.16]), and accelerations (ES = 0.33 [-0.34 to 1.01]) were smaller (p ≤ 0.01) for the 2020 than the 2019 season. Expressed relative to playing time, distance (ES=-0.38 [-1.06 to 0.30]), PlayerLoad™ (ES = -0.27 [-0.94 to 0.41]), and acceleration efforts (ES = -0.50 [-1.18 to 0.18]) were greater (p < 0.05) for the 2020 than the 2019 season. No significant differences in maximum ball-in-play periods nor the difference between the 1st and 4th quarters were evident. Injury rates remained similar between 2019 (3.36 per game) and 2020 (3.55 per game). However, the proportion of injuries that led to lost time (missed games) was greater for the 2020 (38%) than 2019 season (24%). The changes in the rules had a profound impact on player performance and increased the likelihood of time loss injuries.

Physical and technical demands of offence, defence, and contested phases of play in Australian Football.

BACKGROUND: This study compared the physical demands and effect of field location for different phases of play (offence, defence and contested), and examined the physical and technical demands of successful and unsuccessful phases of play during Australian Football matches. METHODS: Global positioning system (GPS) and technical performance data were collected from 32 male Australian Football players in one club over 19 games in the 2019 season. The GPS data was aligned with phases of play acquired using Champion Data. Linear mixed models were used to detect differences between phases of play and field location which were further contextualized using Cohen's d effect size. RESULTS: Physical demands were greatest (p < 0.001) in defensive phases for backs (ES 0.61 to 1.42), and offensive phases for midfielders (ES 0.65 to 0.96) and forwards (ES 0.84 to 1.94). Additionally, distance and high-speed running were lowest in contested phases irrespective of playing position. Distance and high-speed running were greatest in larger field locations (e.g., full ground). No pattern was evident for accelerations or decelerations. Successful offensive plays demonstrated greater physical and technical outputs for midfielders and forwards, whereas the opposite was found for backs. Physical output was largely greater in unsuccessful defensive plays for all positions; however, the rate of tackles and marks was greater during successful defence. CONCLUSION: These findings enable a greater understanding of the demands of Australian Football matches, and can be utilized to inform both representative training design, and the evaluation of player performance.

Physical and technical demands of Australian football: an analysis of maximum ball in play periods.

BACKGROUND: This study compares ball in play (BiP) analyses and both whole game (WG) and quarter averaged data for physical and technical demands of sub-elite Australian football (AF) players competing in the West Australian Football League across playing positions. METHODS: Microsensor data were collected from 33 male AF players in one club over 19 games of the 2019 season. BiP time periods and technical performance data (e.g., kicks) were acquired from the Champion Data timeline of statistics, and time matched to the microsensor data. Linear mixed modelling was utilised to establish differences between maximum BiP periods and averaged data. RESULTS: The analyses indicated significant differences (p < 0.0001) between maximum BiP and WG data for all metrics and all playing position (half-line, key position, and midfielders). The percentage difference was greatest for very high-speed running (171-178%), accelerations (136-142%), high-intensity efforts (128-139%), and high-speed running (134-147%) compared to PlayerLoad™ (50-56%) and total running distance (56-59%). No significant (p > 0.05) differences were evident for maximum BiP periods when they were compared between playing positions (i.e., half line vs key position vs midfield). Significant (p < 0.0001) differences were also noted between maximum BiP phases and averaged data across all 4 quarters, for each microsensor metric, and all playing positions. Technical actions (e.g., kicks and handballs) were observed in 21-48% of maximum BiP phases, depending on playing positions and microsensor metric assessed, with kicks and handballs constituting > 50% of all actions performed. CONCLUSIONS: These results show the BiP analysis method provides a more accurate assessment of the physical demands and technical actions performed by AF players, which are underestimated when using averaged data. The data presented in this study may be used to inform the design and monitoring of representative practice, ensuring that athletes are prepared for both the physical and technical demands of the most demanding passages of play.

Global Positioning System Activity Profile in Male Para Footballers With Cerebral Palsy: Does Training Meet the Match-Play Intensity in a 3-Day National Tournament?

OBJECTIVE: The aim of the study was to compare training and match loads for cerebral palsy football athletes in a state-level development program to assess the specificity of training for competition in the para sport. DESIGN: Time-motion analysis and heart-rate monitoring were applied during 20 training sessions of the Western Australia CP Football 2017 training season and seven competition matches of the 2017 Australian National Championships. The study used an observational study design with between-subjects and within-subjects comparisons of training and match loads. RESULTS: There were no significant differences between training and match loads in players' measurements of speed components and heart rates, with two exceptions: higher match distance covered in very high speed ( g = 0.33) and time in heart rate zone 1 (<75% heart rate max, g = 0.45) and less time in heart rate zone 2 ( g = 0.42). CONCLUSIONS: Our results indicate that the athletes were conditioned to perform at similar intensities implemented during training, as demonstrated by the consistency between competition and training data in total distance, relative speed zones, and relative heart rate zones. Coaches should apply this knowledge in the programming of training volume and intensities to obtain peak match fitness and specifically prepare athletes for competition in cerebral palsy football.

Running Performance of Male Versus Female Players in Australian Football Matches: A Systematic Review.

BACKGROUND: Australian Football is a fast paced, intermittent sport, played by both male and female populations. The aim of this systematic review was to compare male and female Australian Football players, competing at elite and sub-elite levels, for running performance during Australian Football matches based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). METHODS: Medline, SPORTDiscus, and Web of Science searches, using search terms inclusive of Australian Football, movement demands and microsensor technology, returned 2535 potential manuscripts, of which 33 were included in the final analyses. RESULTS: Results indicated that male athletes performed approximately twice the total running distances of their female counterparts, which was likely due to the differences in quarter length (male elite = 20 min, female elite = 15 min (plus time-on). When expressed relative to playing time, the differences between males and females somewhat diminished. However, high-speed running distances covered at velocities > 14.4 km·h-1 (> 4 m·s-1) were substantially greater (≥ 50%) for male than female players. Male and female players recorded similar running intensities during peak periods of play of shorter duration (e.g., around 1 min), but when the analysis window was lengthened, females showed a greater decrement in running performance. CONCLUSION: These results suggest that male players should be exposed to greater training volumes, whereas training intensities should be reasonably comparable across male and female athletes.

Evaluating match running performance in elite Australian football: a narrative review.

During Australian football (AF) matches, players are subjected to high running loads, which are intermittent in nature. There is a growing body of research that highlights factors which can both positively and negatively affect this match running performance (e.g., the total distance travelled by a player during match-play). In order to appropriately evaluate these factors, a thorough search of MEDLINE, SportDiscus and Web of Science databases was performed, with a total of 17 manuscripts included within the final evaluation. The main findings from this review highlighted that match running performance is increased amongst those playing in midfield and half back/forward positions, in players with lower playing experience, as well as in matches against higher quality opponents, and in losing quarters. Additionally, a well-design interchange-rotation strategy may be able to positively affect match running performance. A decrease in match running performance was evident amongst more experienced players, during periods of acute fatigue (e.g., following periods of high intensity activity), during matches played in higher temperatures and matches with an increased number of stoppages. However, no effect of ground hardness or size, as well as responses to self-reported wellness questionnaires was found. Other factors such as finals series matches, pre-season training load and elements related to the schedule have been shown to have substantial conflicting results within the literature, increasing the difficulty in making generalisable conclusions to their effect on match running performance. Developing a thorough understanding of these factors which affect match running performance can aid practitioners and coaches to gain a greater understanding of a player's performance as well as inform the development of strategies for its improvement.

Educational Outcomes of Adolescents Participating in Specialist Sport Programs in Low SES Areas of Western Australia: A Mixed Methods Study.

Specialist Sport Programs (SSPs) are an underexamined activity that combines the best features of two different contexts for adolescent development: a sporting program and a secondary school. A mixed-methods study was conducted to determine the influence of participation in SSPs on the educational outcomes of lower secondary students in Western Australia. The results demonstrated a significant improvement in specialist students' mean grade for Mathematics over the course of a year, while their mean grade for all other subjects, and their level of engagement with school, remained stable over the same period of time. Semi-structured interviews were also conducted with key stakeholders (e.g., specialist students and their parents, as well as teachers and graduates of the SSPs). Overall, the participants felt that SSPs had a positive influence on students' engagement with school, and that this engagement had a positive impact on their academic achievement. Taken together, the results of this research suggest that there is a role for SSPs in promoting positive educational outcomes for lower secondary students attending public schools located in low SES areas.

Reliability and Validity of Maximal Mean and Critical Speed and Metabolic Power in Australian Youth Soccer Players.

The reliability and validity of maximal mean speed (MMS), maximal mean metabolic power (MMPmet), critical speed (CS) and critical metabolic power (CPmet) were examined throughout the 2016-2017 soccer National Youth League competitions. Global positioning system (GPS) data were collected from 20 sub-elite soccer players during a battery of maximal running tests and four home matches. A symmetric moving average algorithm was applied to the instantaneous velocity data using specific time windows (1, 5, 10, 60, 300 and 600 s) and peak values were identified. Additionally, CS and CP¬met values calculated from match data were compared to CS and CPmet values determined from previously validated field tests to assess the validity of match values. Intra-class correlation (one-way random absolute agreement) scores ranged from 0.577 to 0.902 for speed, and from 0.701 to 0.863 for metabolic power values. Coefficients of variation (CV) ranged from good to moderate for speed (4-6%) and metabolic power (4-8%). Only CS and CPmet values were significantly correlated (r = 0.842; 0.700) and not statistically different (p = 0.066; 0.271) to values obtained in a shuttle-running critical test. While the present findings identified match-derived MMS, MMPmet, CS and CPmet to be reliable, only CS and CPmet derived from match play were validated to a CS field test that required changes in speed and direction rather than continuous running. This suggests that both maximal mean and critical speed and metabolic power analyses could be alternatives to absolute distance and speed in the assessment of match running performance during competitive matches.

Comparing Maximal Mean and Critical Speed and Metabolic Powers in Elite and Sub-elite Soccer.

The quantification of maximal mean speed (MMS), maximal mean metabolic power (MMPmet), critical speed (CS) and critical metabolic power (CPmet) was conducted over full A-League (elite) and National Premier League (NPL; sub-elite) seasons. Comparisons were made between levels of soccer competition and playing positions (i. e. centre backs, full backs, central midfielders, wide midfielders and strikers). A symmetric moving average algorithm was applied to the GPS raw data using specific time windows (i. e. 1, 5, 10, 60, 300 and 600 s) and maximal values were obtained. Additionally, these maximal values were used to derive estimates of CS and CPmet. Maximal mean values, particularly during smaller time windows (i. e. 1 and 5 s), were greater in A-League match play. Only MMPmet1 was identified as being consistently different between competitions (P=<0.001-0.049) in all playing positions. Significance was only observed in CS (P=0.005) and CPmet (P=0.005) of centre backs between competitions. Centre backs were identified as the least energy demanding playing position. The present findings suggests that both maximal mean and critical analyses are suitable alternatives to common absolute distance and speed assessments of match running performance during competitive matches.

Greater loss of horizontal force after a repeated-sprint test in footballers with a previous hamstring injury.

OBJECTIVES: To quantify changes in running kinetics and kinematics during a repeated-sprint test in football players, and explore the sensitivity and specificity with which these variables can identify previous hamstring injury. DESIGN: 20 Western Australia State League footballers with previous unilateral hamstring injury and 20 players without completed a 10×6-s repeated-sprint test on a non-motorised treadmill dynamometer. METHODS: Changes in horizontal force, vertical force, contact time and flight time were compared between previously injured and uninjured legs of participants. RESULTS: Mean horizontal force production of the previously injured leg in the injured group was 13% lower (p=0.001), and this magnitude of change was used to identify the injured legs within the cohort with 77% specificity and 85% sensitivity. Furthermore, the area under the Receiver Operating Characteristics curve (0.846) demonstrated that the between-leg difference in mean horizontal force was a good instrument for identifying previous hamstring injury. CONCLUSIONS: There is a greater fatigued-induced change in mean horizontal force during a repeated-sprint test in legs with previous hamstring injury than the non-injured legs of the injured players or the legs of uninjured players. Such asymmetry may contribute to impaired performance in football players returning from hamstring injury and also to the high rate of hamstring re-injury. Rehabilitation and return-to-play strategies should emphasise a reduction in asymmetry, particularly during repeated high-intensity efforts. Furthermore, binary regression and Receiver Operating Characteristic analyses suggest that changes in mean horizontal force could be used to assess risk of hamstring injury, re-injury and/or return to play.

Recreational soccer as sport medicine for middle-aged and older adults: a systematic review.

BACKGROUND: Strategies to prevent or attenuate the age-related decline in physical and physiological function and reduce chronic disease risk factors are of clinical importance. OBJECTIVE: To examine the health benefits of recreational soccer in middle-aged and older adults. DESIGN: Systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. DATA SOURCES: All available records up until 9 June 2017 in PubMed, Web of Science, SPORTDiscus, MEDLINE, Embase, CINAHL Plus, PsycINFO and Cochrane Library databases. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: All randomised trials with or without a control group (randomised controlled trials or randomised uncontrolled trials) and non-randomised controlled trials that used recreational soccer, which includes small-sided soccer games, as the sole or principal intervention, and reported relevant effects in untrained/sedentary, healthy or unhealthy adults aged 40 years and above were included. RESULTS: Five trials described in 13 articles were included, which scored 6-9 out of 12 points on the modified Delphi quality rating scale. The duration was from 12 to 52 weeks, with various frequencies, volumes and game formats performed both outdoors and indoors with men and women. The trials indicate that recreational soccer may result in improvement in cardiovascular function, body composition and functional ability, although no significant changes were observed in postural balance. CONCLUSION: Recreational soccer should be considered an alternative exercise modality for untrained, healthy or unhealthy middle-aged and older adults of both sexes to maintain an active lifestyle and mitigate a wide array of physical and physiological age-related changes.