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SPORTSCIENCE · sportsci.org
News & Comment / Training & Performance
The Ninth World Congress on Science and Football
Will G Hopkins
Sportscience 23, 8-19, 2019 (sportsci.org/2019/WCSF.htm)
Institute for Health and Sport, Victoria University, Melbourne, Australia. Email. Reviewers: Alireza Esmaeili, Victoria Univer-
sity and the Australian Football League, Melbourne, Australia; Matthew Varley, La Trobe University, Melbourne, Australia.
This quadrennial conference on the various football codes had several outstanding
presentations and a high proportion of others that made the conference a great success.
Injury: effect on team performance in Australian football (AF); machine learning in soccer
and rugby league; Caroline Finch's AF programs; prevention programs and a meta-anal-
ysis in various sports; strength and hamstring injury in AF; concussion in AF; headers in
soccer; limb asymmetry prevalence and following ACL reconstruction in soccer; calf-
muscle injuries in soccer; high-speed running in soccer; functional movement screen in
various sports. Match and Movement Analysis: machine learning and match outcome in
AF; scanning in elite soccer; the future of analytics; performance indicators of FC Barce-
lona; pressure and other spatio-temporal measures in various sports; goal scoring in
soccer; kicks in various sports; factors affecting performance indicators and intensity in
various sports. Talent Identification and Development: a talent score for soccer; various
youth academies and development programs; talent requirements for soccer; mental
toughness for soccer; scouting for soccer; becoming a Socceroo; aspirations in soccer;
migration to professional level in soccer; females in AF; retiring from elite AF; 10,000
hours in rugby league; effects of developmental level on performance in various sports.
Tests and Technology: non-linear modeling of modifiers; age of peak height velocity;
defining high-speed running; speed tests in soccer; interval test for soccer; dribble test
for soccer; game animation for soccer; perceived-exertion scale for soccer; small-sided
games for performance in soccer and for kicking in AF; kicking test for AF; accelerome-
ters for kicks; agility test for AF, decision making in AF; management system for AF; GPS
test measures for AF; subjective ratings in AF; signal-to-noise in AF tests; performance
measure for rugby league; heart-rate variability in rugby league. Training Interventions:
noise in soccer training; warm-up in soccer; resistance training in soccer and rugby;
sprint-training in rugby; coping skill in rugby league; scheduling training for rugby-league
matches. Miscellaneous: travel and performance in rugby; sleep intervention for rugby;
travel and sleep in AF; training plans in AF; long-term trends and rule changes in AF;
relative-age effect in AF; females in AF; match load and recovery in AF; fitness and fa-
tigue in AF; training intensity and bio-banding in youth soccer; substitutes warming up in
soccer; effect on club performance after soccer World champs; role of soccer referees;
coaching the coach; career development of SportsCoders. KEYWORDS: AFL, elite ath-
letes, league, match analysis, performance, rugby, soccer, tests, training.
Reprint pdf · Reprint docx
The venue for this special-interest conference Fabio Serpiello and the team from Victoria Uni-
on June 4-7 was virtually in the center of Mel- versity. The venue for the next WCSF has not yet
bourne, Australia, on the edge of the CBD and been announced. Wherever, if it's anything like
the Yarra River. The quality and quantity of food this conference, you would regret missing it, es-
for lunches and tea breaks were phenomenal, the pecially if it doesn't get summarized like this
best of my long experience of conferences. With one.
~300 registrants the atmosphere was friendly In this report I have focused only on injury and
and informal, but there was plenty of good sci- performance, omitting maybe ~20 abstracts on
ence; indeed, the proportion of presentations that other topics. To access those, and the abstracts I
were of value to more than the presenter was far have reviewed, download and browse PDFs of
higher than the usual conference average of the program and the abstracts, available via this
~5%, in my opinion, and there was a 100% turn- link at the conference website. The posters were
out of speakers. A big thank-you to Kevin Ball, included in the abstracts but not in the program,
Sportscience 23, 8-19, 2019Hopkins: Football Conference Page 9
so to browse the poster titles and authors, down- ous application to "the development and im-
load this spreadsheet. I thought the posters were provement of injury prevention strategies."
as good as the orals. [Nikki Rommers]
In my review below, I have identified each ab- On the other hand, with only 36 soft-tissue,
stract with its first author in brackets […]. To non-contact injuries in 48 professional rugby
find the abstract, open the advanced-find win- league players over a season, I am skeptical of
dow (Shirt-Ctrl-F) in the abstract PDF and insert associations with training or lack thereof identi-
the author's name. fied by machine learning. [Cloe Cummins]. Re-
As usual with a conference of any reasonable viewer's comment: the predictive performance
size, program clashes meant that I had to miss of the model was only slightly better than chance
many potentially interesting presentations. I and far from the level of accuracy needed in a
have done my best to summarize these from their practical setting.
abstracts. My two reviewers have been helpful In the opening keynote, Caroline Finch pre-
here. Unfortunately the keynote and invited sented various frameworks she has used to im-
speakers did not have abstracts, so I can summa- plement injury prevention strategies with sports:
rize only those I attended. In my notes on those, TRIPP (translating research into injury-preven-
I often wrote "can't read slides" or "fonts too tion practice) and TIP (team-sport injury preven-
small", so I may have missed important points. tion). In detail, they amount to RE-AIM (Reach
The following presentations of new research the people who need to know about it with an
had what I think earned a Wow! factor: machine Effective program that is Adopted, Implemented
learning to predict injury risk in soccer; effect of and Maintained by the people who need to use
injuries on team performance; machine learning it). One that she rolled out at the community
to predict match outcome in Australian football; level with Australian football is FootyFirst, an
visual scanning by successful players in soccer; evidence-informed warm-up program similar
a talent score at the elite level in youth soccer; to FIFA's 11+. It achieved a 22% reduction in
non-linear modeling for modifiers of injury or injury rate with targeted clubs, while control
performance; and the effect of long-haul travel clubs and the rest of the state experienced a 13-
on performance in rugby. Conference awards for 24% increase. Turnover of coaches is a problem
best presentations are shown in green. for maintenance, so it's important to try to make
To avoid confusing the different football the program part of the culture of the club.
codes, I have referred to association football as Twenty-seven experts provided input to devel-
soccer. I have referred to Aussie-rules football as opment of elements of a neuromuscular train-
Australian football, but in quoting presenters I ing program for women's Australian football
have sometimes kept AFL (Australian Football aimed at reducing the high risk of knee injuries
League). I use football on its own as a generic in female athletes observed in similar team
term. sports. Most elements were similar to those of
Injury the FIFA 11+, while Australian football-specific
Wow! In the first study of the effect of injury preparation and education were unique compo-
on team performance in Australian football nents. [Andrea Bruder] Early career researcher
(20 years of matches, >15,000 injuries), there award.
was a small-moderate smaller standardized A multidisciplinary team achieved a 41% re-
measure of injury burden in finalists compared duction in team injury burden in one season rel-
with non-finalists, particularly when weighted ative to a previous baseline season in 40 players
for player value. Avoid injuries! [Daniel Hoff- of a rugby-league academy. [Jason Tee]
man] A controlled trial of 12 wk of a warm-up pro-
Wow! In a study of 734 players in the under-10 gram in young (age 10-16 y) female soccer
to under-15 age categories from seven Belgian players (39 intervention, 28 control–why weren't
youth soccer academies, "a machine-learning they already doing the FIFA 11+?) improved
algorithm was able to identify 92% of [future] back squat and therefore potentially reduced in-
injury cases correctly based on anthropometric, juries. [Elena Isla Paredes]. People's choice
physical, and coordination tests taken at the start award (oral).
of the season." It also accurately classified inju- A meta-analysis of 10 randomized controlled
ries as overuse or acute. The findings have obvi- trials of injury-reduction strategies (FIFA 11+,
Sportscience 23, 8-19, 2019Hopkins: Football Conference Page 10
etc.) in female soccer players showed a 45% re- by the outcomes in this controlled trial of two fe-
duction in rate of injuries of the anterior cruciate male youth soccer teams. [Thomas Kaminski]
ligament and a 26% reduction in overall rate of A high proportion (~40%) of players (age 8-
injuries. [Benjamin Mentiplay] 15 y) at an Australian soccer academy exhibited
"Our systematic review showed limited scien- between-limb strength asymmetries, a risk fac-
tific evidence to support exercise as an effective tor for injury. [Kerry Peek]
strategy to prevent muscle injury in elite soc- Limb asymmetry in a functional performance
cer." I think the researchers may have placed too battery 1 y after reconstruction of the anterior
much importance on risk of bias. They otherwise cruciate ligament (ACLR) was associated with
found reasonable evidence for benefits of "ec- large to very large (2.1 to 3.7×) increases in risk
centric exercise, proprioception exercises and a of worsening osteoarthritis 5 y later in 78 soccer
multi-dimensional component to injury-pre- players. "Improving limb symmetry post-ACLR
vention programs." [Maurizio Fanchini] may be important to help reduce the burden of an
In this one-season study of three professional ACLR on the athlete." [Brooke Patterson]. In a
Australian football teams, "preseason Nordic related abstract from the same group, the
strength was not different between players who strength deficit persisted for as long as 10 y fol-
did and did not go on to sustain a hamstring in- lowing surgery. [Andrea Bruder]
jury (p>0.05)." The number of players who de- The researchers identified the playing situa-
veloped a hamstring injury was small (13), but tions immediately prior to 24 calf-muscle inju-
all the injured players had better hamstring ries that had an acute onset visible on video ma-
strength than a cut-off identified in a previous terial collated from 9 y of videos of German and
study. [Nigel Smith]. Reviewer's comment: this English soccer club or international matches.
finding highlights the need for caution with cut- "These data support the belief that calf-muscle
off scores developed in one population for pre- injuries transpire as a result of compromised
ventive interventions in another. movement patterns following unsystematic pat-
From an analysis of injuries during the 2009- terns of play." [Ida Bo Steendahl]
11 and 2015-17 seasons (1,334 in 1,060 players) Exposure to high-speed running over two
of an elite junior competition in Australian seasons calculated as either "acute" or "chronic"
football, the risk of new injuries increased by a exposure (mean in the previous 7 or 28 d) in 47
small amount (1.2×), but concussions showed a semi-professional soccer players was associ-
borderline very large increase (3.2×), possibly ated with a small-moderate (1.39-1.74×) in-
due to increased reporting. Risk of recurrent in- crease in risk of non-contact lower-limb injuries.
juries and groin injuries has decreased. "Further [Tim Massard]. But is reducing high-speed run-
investigation of concussion injury is needed." ning an option?
[Samuel Chalmers] Dysfunctional movement in the functional
A cohort of 12 female youth soccer players movement screen "was not associated with in-
followed over a three-month season performed jury" in either of two prospective cohort studies
no headers in training and 0.34 headers per of elite junior Australian football players. The
player per game (range 0 to 6). Given the small correct interpretation is that the association was
sample size, the large range of repetitive head unclear: the confidence limits in both studies al-
impacts from headers, and the current concerns low for moderate to large increased and de-
about concussion, whether this frequency de- creased risk. An observed association between
served to be downplayed by the researcher as asymmetrical movement and injury in the first
"extremely low" remains to be seen. [Victoria study was not observed in the second, highlight-
Wahlquist] ing "the importance of replication studies in
One way to mitigate the effects of heading is football research." Well, yes, but it's more a mat-
greater neck strength, which was associated ter of multiple studies for eventual meta-analy-
with lower head acceleration in this systematic sis. [Joel Fuller]
review of five observational studies. [Kerry A sample size of 809 elite junior Australian
Peek]. And the intervention component of an football athletes across four seasons is more rea-
online coach-training program (Get aHEAD sonable for concluding that "no functional
Safely in Soccer) focusing on neck size and movement screen score threshold effectively
neck/torso strength is one way to do it, judging identified all-cause or non-contact injury risk."
[Emma Moore]
Sportscience 23, 8-19, 2019Hopkins: Football Conference Page 11
But a meta-analysis of the effect of func- priority for applied practice" in team sports. In-
tional movement screen score on injury risk deed, and this study of 48 male soccer players
showed that "scores were more useful for esti- showed effects of playing position, pitch posi-
mating injury risk in senior compared to junior tion and phase of play on scanning actions quan-
athletes. Effect sizes tended to be small except tified with inertial measurement units. [Thomas
for scores in rugby, ice hockey, and American McGuckian]
football athletes," where the effects were actu- In a keynote on the future of [high-tech] ana-
ally very large (odds ratios and therefore approx- lytics in football, Sam Robertson made the fol-
imate hazard ratios of 3.7-5.9). [Emma Moore]. lowing key points: we now get so much data
So why are there little or no effects in Australian from wearable and other technologies that ana-
football? lytics are a matter of necessity; there is a short-
Match and Movement Analysis age of skilled workers to implement the analytics
Wow! The best of several machine-learning in the field (students, take note); and analytics
models applied to 152 variables and match out- can outperform expert opinion in talent identifi-
come in the 2013-2017 elite Australian football cation and injury prevention (don't tell the coach,
seasons predicted match outcome in the 2018 Sam!). In his opinion, the theoretical underpin-
season slightly better than bookmakers (74% vs nings of analytics are still weak, and analytics
71%). "Measures of team quality (a team-based need to catch up with performance indicators at
rating and a player-based rating) were the two the level of the team.
most important variables for prediction by a sig- Tracking the relative positions of every player
nificant margin. These were followed by the provided measures of space, superiority and
availability of top 10 players. All three measures positioning that showed clear differences be-
were better in their relative form against the op- tween the elite football club FC Barcelona and
position." [Jack Fahey-Gilmour] their opponents in six games of the European
Wow! From an analysis of videos of matches to elite soccer league (UEFA), but it’s a work in
quantify how world-class soccer players use progress. [Angel Ric]
visual exploratory behavior to scan the envi- Another promising work in progress is an at-
ronment: "players are more successful in their tacker-defender model of one-on-one dribble
forward actions and complete more penetrating dynamics, which identified seven different drib-
forward passes when exploring more." The con- bling scenarios with FC Barcelona. [Lukas
clusion: "development of visual exploratory be- Brink]
havior should be highly emphasized in football And an unusual (to say the least!) parallel was
players’ daily training." [Geir Jordet] drawn between FC Barcelona's "passion for
In his keynote, Geir Jordet predicted a revolu- width" apparent in video analysis of pattern for-
tion in applied psychology in relation to the fol- mation in team coordination across age groups
lowing areas of soccer: sophisticated in-match at the club and an "egalitarian passion for width
metrics, cognitive training, simulation technolo- facilitating the co-creation and sharing of space,
gies, the coach as a psych specialist, and integra- evident in 17th century Catalan gothic architec-
tion of all the above with other aspects of perfor- ture." [James Vaughan]
mance analysis. An example of the in-match On the basis of the areas enclosed by the near-
metrics is scanning (visual exploration) by play- est four players on receipt and release of the ball
ers in the seconds before they receive the ball: (a measure of "pressure") in six games of the
it's a predictor of successful forward passing, but German junior soccer league, "the pitch size
with 10 measureable scanning behaviors, it takes for 4v4 small-sided games in training should
too long to code manually. He is hoping for real- range between 450-500 m² to correspond with
time automatic coding with on-screen vectors in- competition demands." [Andreas Prof. Dr.
dicating where the head is turned. Virtual real- Hohmann]. Some of the factors affecting pres-
ity for training, especially following injury, is sure in the different levels are in an accompany-
another development: players like it, but how ing abstract. Both are first authored by Micha Dr.
well it transfers to actual performance is still not Pietzonka.
clear. "During pressing situations, defenders coordi-
"A growing body of evidence suggests that the nate their behavior to increase the likelihood of
development of visual exploration should be a regaining possession." In this analysis of posi-
tional data from 48 matches of the German elite
Sportscience 23, 8-19, 2019Hopkins: Football Conference Page 12
soccer league (Bundesliga), "higher velocity Height and weight "of players involved in the
[unstated magnitude] of the nearest two defend- aerial moments into the box, had a trivial to mod-
ers within the first second of the pressing se- erate effect in several of the match performance
quence are related to more successful ball recov- indicators" in this analysis of 24,000 corner
eries." [Jan-Paul de Jong] kicks and 6800 open-play crosses into the box
This analysis of player tracking data from nine in a season of European elite soccer league
matches of one Dutch premier league soccer matches. The results "would help the teams to
team showed that successful passing in the final better prepare for dispute the aerial duels in the
third of the field was associated with greater dis- different game moments, through the reposition-
ruptiveness of the defender's spatial organiza- ing of their players on the field." [Rui Marcelino]
tion, but "insights in how tactics contribute to the From an analysis of 461 goal shots in the 2018
disruption of the opposition" are not presented in soccer World Cup, "the following may facili-
the abstract and I missed the presentation. [Floris tate the goalkeeper's task in guarding the goal:
Goes] when shots originate from distance, the goal-
The same group performed an analysis of keeper should preferably adopt a posture that fa-
tracking data of all 22 players and the ball from cilitates stepping; when the shot is originates
82 professional soccer matches to show that a from close, the goalkeeper should adopt a pos-
composite spatio-temporal measure of the de- ture facilitating easier diving for the ball when
fenders predicted shots on goal. [Matthias the ball cannot be handled while standing."
Kempe] [Keita Matsukura]
"Perturbations (any action which disrupts the After analyzing 697 shots at goal in the Aus-
stability of the game) are associated with success tralian soccer A league, the authors concluded
for men’s and women’s Rugby-7s teams… that "whilst more difficult to execute, it may be
Evasive footwork was the most commonly oc- profitable for strikers to select shot placement
curring perturbation." [James Barkell] relative to the goal keeper instead of the goal."
I can't pretend to understand this abstract, but [Scott Peterson]
it looks like a valuable application of machine I guess not surprisingly, "it may be easier to
learning to the question of estimating optimal score a goal if there are fewer players including
passing from two seasons of player-tracking opponents in front" in this analysis of 1106 shots
data in the Australian football league. [Barthol- at goal in a soccer World cup. [Masao Naka-
omew Spencer] yama]
A simulation of collective behavior in foot- The researcher presented a model for soccer
ball matches looks like a valuable work in pro- that can "match individual shooters against indi-
gress. [Mathieu Feigean] vidual goalkeepers to identify the optimal
It's hard to understand this abstract, but it shooting strategy for that specific matchup."
looks like measures of performance indicators What the model was based on is not stated in the
for defense in soccer are also a work in progress. abstract, but check it out for the specific advice.
[Hiroshi Yamada] [Andrew Hunter]
Attacks that take advantage of the gap be- Factors affecting 29,153 field kicks in three
tween the opponent’s defenders and mid- tiers of Australian football were described a lit-
fielders are more likely to lead to scoring oppor- tle confusingly as "constraints" (e.g., physical
tunities. This abstract goes into the details for 64 pressure resulted in lower kicking effectiveness).
games in the junior and senior German soccer "A multi-variate analysis revealed the 10 most
leagues. [Kensuke Suzuki] confident rules [?] for each tier." [Peter Browne]
Cluster phase analysis in positional data of one The conclusion of this study of simulated
team of semi-professional female rugby league match movements of 12 division-2 Australian
players in a 3-d tournament showed that "greater footballers is that "it is possible to count kicks
synchrony may be detrimental in defence result- with a high accuracy in game-like conditions
ing in tactical inflexibility when trying to adapt with the use of inertial measurement units." [S.
to opposition play." [Kathleen Shorter] Ellens]
A cluster analysis identified three playing "Our results demonstrate subtle differences in
styles in 360 games of a season of the English support-leg hip mechanics of inaccurate and ac-
premier soccer league. Playing style changed curate rugby place kickers," suggesting (unsur-
depending on opposition quality. [Stuart Gollan] prisingly?) "hip joint motion may be important
Sportscience 23, 8-19, 2019Hopkins: Football Conference Page 13
in achieving an accurate kick." [Alexandra C. Thoseby, Ben Dascombe].
Atack] The authors of this study quantified "the tech-
"Winning teams kick more, particularly from nical skill demands of key performance indica-
the scrum half, but they also have a higher rela- tors of a professional Australian football team
tive frequency of positive outcomes from these through pre-season training, the 5-wk preseason
kicks" in the analysis of 11,800 kicks in English competitions and the first 5 weeks of the com-
professional rugby union. [Neil Bezodis] petitive season." [Joshua Stein]
The conclusion following analysis of kicks of There were significant positional differences
a rugby ball with a mechanical foot: "the best in accelerometer- and GPS-derived measures
impact position for distance would be nearest to in league and championship games of a team of
the belly of the ball." [Riccardo Michelini] elite male Gaelic footballers. [Declan Gamble]
The side volley or flying kick in soccer is an Read this abstract for the expected differences
airborne kicking technique creating "breathtak- in player movement profiles in games at three
ing moments and cherished memories for play- levels of American football. [Jason Berry].
ers and fans… Given the rarity of players who Here's a similar study: "Games are higher inten-
have acquired this skill, we found only 3 subjects sity compared to practice" across the various
for the study" of factors contributing to quality playing positions in this analysis of academy, di-
of 12 kicks. The factors were flexibility of the vision-1 college and national-level players of
hip, the efficiency of the whip-like movement of American football. [Bill Burghardt]
the kicking leg, and the damping mechanism Talent Identification and Development
during falling. [Gongbing Shan] Wow! A cumulative talent score for a range
In a season of the Chinese soccer Super of physical, technical and tactical tests was
league, situational variables (home vs away higher for all but one of 18 elite youth soccer
game, strength of team and opponent) had major players in the national team compared with 24
effects on indicators of technical performance players in the state elite team. Has there ever
but trivial effects on indicators of physical per- been a more powerful measure for talent identi-
formance, whereas environmental factors (hu- fication at such a high level? The individual test
midity, temperature, air quality) affected mainly scores are obviously also valuable for talent de-
the physical performance but had only trivial-to- velopment. The researchers just added up all the
small effects on technical performance. scores from each test, so the discriminatory
[Changjing Zhou, presented by Hongyou Liu] power of the cumulative score is not an artefact
Various contextual factors had substantial of a stepwise procedure with the small sample
and trivial effects on GPS-derived measures in size. [Brad Keller]
five women's elite Australian football Experienced panelists in a discussion on
matches. [Rhearne Ryan] youth football academies were Warren Greg-
In an invited lecture, Grant Duthie, "a sport son, Jason Berry and Antonio Figeuiredo, ex-
scientist integrated with the coach and sport" (his pertly chaired by Fabio Serpiello. The following
words, no abstract), spoke of the value of know- points emergerd… The academy system results
ing the distribution of intensities in rugby in early specialization because of parents' ex-
games to make training drills similar to games. pectations, yet success stories with early special-
And, "players who don't have the fitness will ization (e.g., Tiger Woods, the Williams sisters)
slow up the others." are rare. There are many examples of top athletes
Maximum match intensities for durations coming from multi- or other sport backgrounds,
ranging from 5 s to 10 min for the 30 players in and these could be used for education. Early spe-
each of a sub-elite and elite professional rugby cialization leads to increased injuries and drop-
team were quantified in a season of matches us- outs. Leave specialization open for as long as
ing GPS units with embedded accelerometers. possible. Doing other sports throughout career
The data can be used "to prescribe and monitor development can extend an athlete's career. The
duration- and position-specific training that rep- Brazilian academy system is failing, because it
resents or exceeds peak periods of competition. is too standardized and structured–it needs to be
[Samuel Howe]. Similar data were presented for made more "messi" (referring to the background
44 elite youth female soccer players [Stacey of the great Lionel Messi). In Portugal soccer
Emmonds] and 44 players of an Australian A- clubs are introducing other sports, partly to de-
league soccer club across three seasons [Bradley velop soccer skills; kids enjoy it, but parents and
Sportscience 23, 8-19, 2019Hopkins: Football Conference Page 14
coaches need persuading. Maturation can be "Structuring the scouting procedure may re-
worth measuring to predict adult height and duce bias and lead to more accurate player rec-
therefore specialization for a playing position, ommendations" is the conclusion from this con-
but it is unclear how best to prescribe training trolled-trial of 18 male soccer talent scouts as-
around the age of peak height velocity (except to signed to assess three videos each of three adult
avoid excessive loads). Bio-banding (training professional central midfielders either with or
kids in maturity groups rather than age groups) without structuring for three indicators deemed
might have the unintended consequence of re- essential by the club: forward pass percentage,
ducing the challenge and therefore development percentage of successful interceptions and per-
of late maturers. centage of duels won. [Wouter Frencken]
This Hungarian researcher's take on elite What characterized the developmental path-
youth soccer academies is that "a centrally de- way to becoming a Socceroo (a member of the
termined and science-based age- and position- Australian national soccer team) in the era
specific test system helps the players’ long-term 2003-2014? The researchers in this mixed-
performance development," and that you need method (qualitative-quantitative) study found
experts with "lots of mandatory qualifications." that "players started playing at an early age (i.e.,
Maybe, but don't forget the Messis. [David 5 years of age), fostered by the support of family
Zalai] members, with the majority of their time in un-
The Athletic Skills Model is a talent-develop- structured play. There was a strong connection
ment program for soccer in the Netherlands to the local club, with many following the com-
that aims to combine early and late specialization mon Australian football pathway, until an early
"by engaging young athletes in a structured and move overseas." [Paul Larkin]
varied movement program." [Geert Savelsbergh] A correlational study of 144 female youth
A qualitative case study of an English youth soccer players from 14 English teams showed
soccer academy found that "academy involve- moderate to large associations between percep-
ment is neither inherently good nor bad but has tions of the talent development environment,
potential in both directions." The good was bet- career aspirations and career intentions. "Creat-
ter well-being, stress and recovery compared ing more positive perceptions of a long-term de-
with European average; the bad was a higher rate velopment focus is likely to be beneficial."
of injuries. [Fieke Rongen] [Adam Gledhill]
In another qualitative case study of an Austral- If your youth soccer players are likely to mi-
ian youth soccer academy, the aim was to assess grate to play with a professional club, this com-
the implementation of a player evaluation sys- prehensive set of three qualitative studies in
tem. "For a player evaluation system to be effec- Malta shows that you can intervene to ease the
tive, all stakeholders must ensure the system is stress of the transition. [Adele Muscat]
player-centered, with players taking ownership A qualitative case study of integration of new
on goal-setting, feedback, and dictating [!] the players into a professional Australian women's
player-coach-parent meeting." [Kasey Paradis] soccer club (involving 16 of the 19 players)
Eight elite-level soccer coaches came up with "identified several facilitators (e.g., socializing
the talent requirements of the six playing posi- outside the club, shared goals, transparency in
tions, and the researcher combined these into a communication) and barriers (e.g., cliques, a dis-
useful tool for coach and player development us- ruptive preseason, role acceptance) to players’
ing Work Domain Analysis (a human-factors feelings of integration. The link between integra-
systems analysis method). [Elise Berber] tion and team cohesion was prominent, elucidat-
When 40 elite youth female soccer players ing the influence on team performance." [Dianna
were median-split into two groups on their men- Lepore]
tal toughness score, the high-toughness group The abstract on a grounded theory for attract-
had better scores (small to large in magnitude) ing and retaining participation of females in
on a wide range of soccer-specific fitness and Australian football is of the results-will-be-pre-
skill tests. "Assessing the level of mental tough- sented variety. Contact the author for more in-
ness among youth female soccer players may formation. [Sam Elliott]. Best AFL presentation.
provide coaches with more useful information "One of the major sources of stress for athletes
during talent identification and selection." is the transition out of sport." Hence this qual-
[Del P. Wong] itative study of 10 female athletes, who were
Sportscience 23, 8-19, 2019Hopkins: Football Conference Page 15
delisted from elite Australian football and Pearce]
chose to return to sub-elite competition rather In this study of two teams, "clinically relevant
than cease competing entirely. "Choosing to differences between levels exist in physical fit-
continue playing at a lower level can offer some ness qualities between elite senior and junior
protective factors such as friendship, structure female Australian footballers, with senior
and financial support." [Deb Agnew] players having better balance and greater trunk
The 10,000-hours rule! Twenty-six rugby- muscle endurance. Few positional variances
league players who had progressed to profes- exist." [Jessica Farley]
sional status had spent 6100 ± 4000 (mean ± SD) In another study of differences between com-
hours in rugby-specific play and 3100 ± 1600 petitive levels, "endurance fitness, speed, and
hours in rugby-specific practice, nearly twice as agility were markedly better" in 51 female state-
much as other players. [Matthew Andrew] level Australian footballers than in 50 local di-
The remaining abstracts in this section feature vision-1 players. [Jade Haycraft]
comparisons of performance in various tests "Endurance fitness, speed, and agility were
with groups of athletes of different developmen- markedly better" in 51 state Australian football
tal and/or skill levels… players than in 50 local division-1 players. [Jade
A sample of 102 Norwegian under-14 soccer Haycraft]
players were compared according to their com- Read this abstract for performance-test char-
petitive status: elite (26), sub-elite (53) and non- acteristics of 85 elite female Australian foot-
elite (23). There were the expected differences ball players from three clubs. [Benjamin
("pHopkins: Football Conference Page 16
Rommers] quantify kick variables for athlete skill monitor-
It will be worth close inspection of this sys- ing applications, accelerometers should have a
tematic review of speed tests in soccer when it recommended range of above ±80 g." [Emily E.
appears in a journal, to see which ones best dis- Cust]
tinguish between players of different levels. The design and development of a novel system
However, there don't appear to be any data on the capable of testing all components of agility of
most important question: to what extent do these Australian footballers is reported in this ab-
tests track changes in match performance indica- stract. [Reuben Smith]
tors of individuals and teams? [Stefan Altmann] 360° virtual-reality footage performs well for
An intense field aerobic interval training test assessment of decision-making in athletes and
was a good predictor of maximum oxygen up- umpires of Australian football. [Aden Kittel].
take in 19 male elite soccer players. [Juan C. Student investigator award.
Mazza] In an "industry presentation" scheduled in
"Our new closed-skill dribbling assessment keynote time, Alex Sakadjian of the Melbourne
[involving a curved path, assessed in over 1000 Australian football club sang the praises of the
trials with players of a Brazilian soccer acad- Edge10 athlete management system providing
emy] is a valid and reliable protocol to predict a more time for "why" meetings to discuss individ-
soccer player’s success in attacking and defend- ual training plans with athletes.
ing performance in 1 vs 1 situations, and can be This abstract contains details of design and
used to identify talented junior players." [Nicho- analysis of a small-sided game in Australian
las Smith] football aimed at assessing kicking efficiency.
Unfortunately I didn't see the presentation of a "Coaches and players agreed the test can assess
novel method for "topographical, animated ren- kicking efficiency and was representative of
dering of gameplay [,which] was successful match-play constraints… Assessments from this
and completed at a rate three times faster than test can be used to measure and monitor kicking
real time and enabled the user to monitor all performance along the AFL talent pathway."
players and their response to opponents or the [Nathan Bonney]
ball" in one match of the Danish soccer league. On the basis of data from 28 male profes-
If it lives up to the hype, you will be seeing much sional Australian football players monitored
more of it. [Scott Peterson] for two seasons, the authors argue for replacing
Numerical blinding of a scale for perceived an intermittent fitness test and peak-speed test
exertion didn't make any real difference with with measures taken with GPS from matches and
male youth soccer players, judging by the cor- a 3-km time trial. [Pat Dillon]. Reviewer's com-
relation with the usual scale (0.98). [Ric Lovell] ment: it wasn't clear how many matches were re-
Can small-sided games provide useful quired to determine peak speed; monitoring for
measures of player performance? The study two seasons to get a fitness characteristic is a bit
consisted of impractical shuffling of players of a unrealistic.
professional soccer academy into 11 7v7 Subjective ratings of player performance in
games; the correlations were reasonable for un- all 1034 matches of the 2013-2017 Australian
der-19 players but counterintuitive for the under- football seasons were accounted for by "a select
23s. So I think the answer is no. [Tom L. G. few" of nine common match performance indi-
Bergkamp] cators, depending on the player role. OK, but it's
Technical skill (dribbling, passing, control, not clear how "AFL organizations should utilize
balance) was a better predictor of success in the findings" beyond gaining "a better under-
small-sided games than physical performance standing of the differences associated with sub-
(speed, strength, agility and endurance) in an jective performance assessment." [Sam McIn-
analysis of seven studies from an elite Brazilian tosh]
junior soccer academy. [Robbie Wilson] The researchers claim that signal-to-noise ra-
The authors of this abstract developed a kick- tio, "calculated by dividing weekly coefficient of
ing test "to measure and monitor kicking perfor- variation by test coefficient of variation", shows
mance along the talent pathway" in Australian acceptable sensitivity for all the usual monitor-
football. [Nathan Bonney] ing measures in 42 professional Australian
The conclusion following analysis of kicks of footballers. [Samuel Ryan]. Don't you have to
two experienced Australian footballers: "to account for smallest important changes?
Sportscience 23, 8-19, 2019Hopkins: Football Conference Page 17
The authors describe a new measure of player eccentric training produced moderate improve-
performance in rugby league, based on a ments in an agility test and a 20-m shuttle run
model that estimates the expected point outcome relative to the usual training. [Giuseppe
at a player level in a possession given a tackle Coratella]
count. As yet there is no assessment of validity Adding one session a week of barbell hip
or reliability. [Robert Nguyen] thrusts improved horizontal jump and sprint to a
Is it worth measuring heart-rate variability (possibly? likely?) greater extent than did back
(HRV) along with subjective measures prior to half squats in this controlled trial of 3x8 under-
matches? Correlations of individual HRV and 17 soccer players with no previous experience in
subjective measures with various performance strength training. [Eduardo Abade]
indicators from 30 players in the matches of the Adjusting resistance training load to an indi-
national rugby-league season reached ~0.4, and vidual's rate of adaptation can be done with sub-
there was only modest improvement when jective ratings of exertion or objective intensity
measures were combined with multiple linear re- (barbell velocity). The methods were compared
gression (possibly just due to sampling varia- in this crossover study of two 6-wk blocks with
tion). According to the speaker, HRV is not re- 20 amateur rugby union players. It's unclear
lated to over-reaching, so I'd say HRV is not whether there was a washout between the blocks,
worth the hassle. [Anthony Leicht] so the results are hard to interpret, but it looks
Training Interventions like objective feedback was likely to produce
Jaime Sampaio's keynote was of little benefit bigger gains. [Jason Tee]
to me because of my poor hearing (he's a quiet Design, sample size and level of athletes are
speaker) and bad eyesight (for some slides). My not stated, but it was apparently a controlled trial
notes say only "signal to noise": adding noise of acute effects of repeated-sprint training in
can enhance learning of the signal. He showed rugby union players with four kinds of sets of
several entertaining videos of adding noise to ~5-s reps (2x6, 4x3, 12x1, and a "velocity-loss"
soccer training sessions in the form of move- allocation), with 20 s between reps and 40-240 s
ment restriction, playing on a slope, playing with between sets. Evidence favored the 12x1 for
a rugby ball, and so on, all aimed at enhancing maintaining sprint speed. [Jonathon Weakley]
performance. He ran a popular workshop about A coping-skill intervention consisting of six
it on the last day, too. education sessions over 8 wk in an under-20
In a crossover study of 12 soccer players elite rugby-league team increased the use of
(level not stated), "a short warm-up is as effec- problem- and emotion-focused coping strategies
tive as long warm-ups for sprint, repeated sprints and reduced disengagement strategies compared
and intermediate running performance in soccer, with a control team. [Balin Cupples]
but mentally less exhausting." [Roland van den It was a time series rather than a controlled
Tillaar]. Yes, but what about the components of trial, and abbreviations made the results difficult
warm-up aimed at reducing risk of injury? to interpret, but it looks like "physical and tech-
In their first experience of traditional re- nical performance [in matches] was unaffected
sistance training, 32 male youth soccer players by scheduling main training closer to matches"
all within 2 y of age of peak height velocity in a team of 34 professional rugby league play-
showed moderate-large increases in 3RM ers over one season. [Tahleya Eggers]
strength and single-leg raises but moderate im- Miscellaneous
pairment of sprint time after 9 wk. Randomiza- Wow! In an analysis of match outcomes of 20
tion of 22 players to a further 12 wk of traditional y of Super rugby games, the detrimental effects
or eccentric training resulted in generally unclear of long-haul travel around the Southern Hemi-
differences in further changes, and modifying ef- sphere turned out to be due almost entirely to the
fects of age relative to age of peak height veloc- away-game disadvantage. Performance indica-
ity were also generally unclear. [Bhargava, A] tors from the last 10 y of matches showed "evo-
In what appears to have been a randomized lution toward a more physical game despite clear
controlled trial, 40 semi-professional male soc- reductions following changes in rules and com-
cer players engaged in either usual training or 1 petition format." [Michele Lo]. Best rugby-
d per wk extra enhanced-eccentric training for codes presentation.
8 wk. Aside from expected adaptations in muscle Whole-body cryotherapy and a high heat-ca-
architecture and hamstrings-to-quadriceps ratio,
Sportscience 23, 8-19, 2019Hopkins: Football Conference Page 18
pacity mattress produced "significant" improve- In a commentary on the current state of wom-
ments in measures of sleep (slow-wave sleep and en's elite sport in Australia, the presenter called
wake after sleep onset respectively) compared for support for female athletes through commu-
with control in a crossover of 10 elite male nity engagement, establishing a strong develop-
rugby players each after a rugby match. The ab- ment pathway, and refining the elite athlete en-
stract shows no data and I missed the talk, so I vironment. She also wants more research on fe-
can't assess whether "no significant differences" male athletes. In question time, I pointed out that
in markers of recovery (counter-movement it's better to study all-female samples than to mix
jump, creatine kinase, muscle soreness) the next the genders. [Anthea Clarke]
day justified the claim that the treatments "did Disappointingly, various measures of match
not have any impact" thereon. [Anis Aloulou] load had "no meaningful effects" on recovery of
A case study of an elite academy team of male various performance-test measures 72 h after ~7
Australian football players showed little effect Australian football matches in a team of 32 na-
on sleep quality of westward flight across nine tional-level players. Of various measures of pre-
time zones. "These results may be explained by season fitness, only lower-body strength had a
the implementation of a team-wide sleep hy- (clear?) moderating effect on recovery, higher
giene education and light exposure program." strength being beneficial. [Dean Norris]
[Stella Veith] The same author presented similar lack of
"Using the pre-season schedule of an elite moderating effects of pre-season fitness in the
Australian football team as a template… feasi- Australian football national-level players on a
ble training plans that maximize projected per- measure that probably represented fatigue accu-
formance and satisfy injury risk constraints can mulated over a season (reduction in the rate of
be automatically generated." It's not clear how force development in a counter-movement jump
you would adapt it to individualized prescrip- and mid-thigh isometric pull). [Dean Norris]
tions. [David Carey] "The aim of this pilot study was to examine the
Kevin Norton's topic for the Tom Reilly me- impact of bio-banding on performances in reg-
morial lecture was high-performance football. ular and bio-banded [youth] soccer games."
He made the following observations about long- There were only 15 boys (5 early-, 6 normal- and
term developments: players are now bigger, be- 5 late-developers), but they were coded in 35
cause bigger means better; volume of training state-level and 6 bio-banded games. The differ-
has halved in recent decades, but game intensity ences suggested that bio-banded games pre-
has increased; goal-scoring has declined, be- sented a greater physical challenge for the early
cause play has become more defensive (espe- maturers, whereas they provided more opportu-
cially in Australian football over the last 10 nities to display physical attributes and attempt
years); rule changes aimed at making it a free- new skills for the late developers. [John Bran-
flowing game (what the fans want) have not nan]. This study would have got a Wow! with 10
worked, and it's not clear what to try next. boys in each group. Reviewer's comment: any
Further to the topic of rule changes, David balancing or adjustment for playing position?
Rath, an office-bearer in the Australian football Various measures of intensity of training
league, gave a keynote in which he pointed out monitored for two seasons in 18 under-15 acad-
that, where previously they convened a commit- emy soccer players showed a clear effect of pre-
tee of experts, now they engage more with data dicted age of peak height velocity, with late ma-
and especially with the community of fans to get turers training at moderately higher absolute in-
"the wisdom of the crowd." tensity (due somehow to their smaller size) and
The relative-age effect (whereby older ath- even higher relative intensity (due to their lower
letes in an age cohort are more likely to progress) absolute maxima). The higher intensity may ex-
is evident in Australian football as early as the plain the known higher injury risk in the late ma-
10- to 12- age-group and continues to the senior turers. [Fabio Serpiello]. Reviewer's comment:
level. [Rhys Tribolet]. It was also present in playing position might also be important.
5336 players who competed at the FIFA Read this abstract if you are interested in what
women’s soccer World cup. "Coaches and talent the substitutes for one English championship
developer should … ensure talent is not missed soccer team did before (in the re-warmup) and
by focusing selection on older players." [Naomi after they went on the field. [Samuel P. Hills]
Datson] "The more players that clubs delegated to the
Sportscience 23, 8-19, 2019Hopkins: Football Conference Page 19
2018 soccer World Championship, the more
the clubs performed below expectations at the
beginning of the new season" apparently because
delegated players have a much shorter recovery
and preparation time for the new season. "This
raises the question, whether FIFA's compensa-
tion for participating players is adequate: [an in-
credible] $8,400 per player per day until drop-
ping out of the tournament." [Hannes Kulok,
presented by Martin Lames]
Interviews with nine Australian national-level
soccer referees revealed that, in their opinion,
the role of the referee is not just judging fouls.
There were apparently four decision-making pri-
orities: safety, fairness, accuracy and entertain-
ment. [Scott Russel]. Best soccer presentation.
In "coaching the coach", a review of non-
sport coaching literature, the presenter identi-
fied four categories for coaching professionals to
enhance performance and career: skills, perfor-
mance, development, and transformational.
"Sports coaches are encouraged to seek quali-
fied executive coaching to facilitate their learn-
ing and effectiveness as a coach." [Andrew Daw-
son]
Jay Ellis presented an invited industry-spon-
sored lecture on facilitating the career growth
of young sports professionals. He described
how Hudl, the makers of SportsCode, support
programs for junior analysts (don’t call them in-
terns) in 200 institutions worldwide, with the
aim of creating good analysts who are also good
communicators. Reviewer's comment: yes, but
with so many free junior analysts, clubs aren't
providing enough jobs for full-time analysts.
Acknowledgements: Victoria University paid for my
registration and accommodation.
Published June 2019
©2019
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