I spent this week at the World Congress of Science in Soccer in glorious sunshine at Portland, Oregon. WCSS is a spin off from the four yearly World Congress of Science and Football, which covers all of the football codes and reconvenes next year in Copenhagen (http://wcsf2015.ku.dk). This was the first time WCSS was to be held in the USA, thanks to the work of Programme Chair Dr Terry Favero.
There were a range of backgrounds and occupations as Terry Favero displayed in the opening address with a nice data visualization piece. Being in America there was a greater involvement of college soccer staff, which led to some interesting discussions regarding contact time, competition organization and developmental pathways for their athletes. Naturally the conference may have been slightly affected by the absence of leading practitioners busy with National Teams at the World Cup (and my personal hindrance of my brain’s refusal to work properly in the offseason) but still many top speakers and positives to take from it.
In one of the first invited speaker sessions Chris Carling from Lille and Manchester United presented the work in his recent publication ‘Time-motion analyses of physical performance in professional soccer match play: time to be more pragmatic?’ Despite the contemporary opinion of practitioners that highlight the importance of physical performance as a key contributor to team match success, research shows there is actually no link between competitive running and ‘success’. For example running demands are actually lower in the Premier League vs Championship and League One, possibly due to the higher technical performance required. Further more despite another widespread opinion that drops in such physical measures are a representation of fatigue during match play, Chris highlights there is no consensus on % difference that represents ‘accumulated’ or ‘transient’ fatigue. These doubts remind me of the Warren Gregson and co’s paper (http://www.footballexchange.co.uk/wp-content/uploads/2011/09/Match-to-Match-variability-of-high-speed-activities.pdf) on the high variability in match play and the large sample size you require to make meaningful conclusion from physical match data. I cannot help but be left wondering what actually are the key uses for physical match data in performance analysis?!
For me the next frontier surely is trying to merge the physical analysis with tactical context to give coaches information that relates specifically to their game plan (in an efficient and manageable way). Perhaps it is the ultimate in Sport Science; the ultimate combination of art and science that we are striving for. Given that tactical requirements can limit physical contribution surely we need to look at the two in tandem; developing distances, speed and sprints in isolation into third man runs, pressing and timing of movements. However, I was left disappointed by the talks here relating to tactical match analysis (admittedly I did not see them all), which came from an academic background speaking of centroids and dyads rather than the language of a coach’s game plan.
A trend gathering pace in the science of football is relating work done as a measure of individual physiological capacity, rather than absolute physical outputs. Chris Carling made this point in his discussion around physical match data. As did Paul Bradley who presented his vast project analyzing the physical and technical performance parameters across seven seasons of the Premier League. He displayed significant increases in high intensity running distance, sprint distance and proportion of explosive sprints, and increases in the technical parameters of number of passes and short passes. It was suggested that the change in tactics over this time rather than increase in physical capacity (physical test results have not increased over time) that cause this evolution. Consequently players are taxing their physical systems at a higher level. Martin Buchheit presented his solution to this with his 30-15 Intermittent Fitness test and the ability to use the test result (VIFT) to monitor and prescribe conditioning.
There were of course renowned Sport Scientists speaking such as Martin Buchheit, Shona Halson, Aaron Coutts and James Morton, all of whom I have been spoilt by already seeing recently on the intensive week of lectures for the Masters course in High Performance Sport at ACU. They are all carrying out applied research with implications to football, across some of the key pillars of applied sport science: training prescription, load monitoring, nutrition, sleep and recovery. If you are yet to read or watch their work then look them up.
With Martin Buchheit we were treated to as many as five of his slick Prezi talks. In one he presented data from PSG U14s over six months that demonstrated the high variability across physiological, locomotor and perceptual responses to small sided games via intraclass correlation coefficients. Given the limited reliability (mean ICCs across metrics ranged from x to y) there are issues with predicting the responses to small sided games and therefore he adds more evidence to the debate regarding their use as a training approach to develop physical capacities. In another talk, I was somewhat disappointed by the panel on fitness testing, but purely due to my desire to witness a full scale battle between Bangsbo’s YoYo and Buchheit’s 30-15 intermittent fitness test!!
It was his work on integrating different tracking systems that caught my eye the most: 2x GPS systems (GPSports and VX), semi-automated multiple camera (Prozone) and local position measurement technology (InMotio). There were a range of differences of magnitudes across various metrics between the systems and in some case differing directions to the range. They were able to generate calibration equations using linear regression models that enable the different systems to be used interchangeably but with great care as there were moderate typical errors of estimate. Seeing as though GPS for training and semi automated systems in matches seem here to stay (and FIFA are unlikely to allow GPS in competition) compiling these and trying to reduce the typical errors may become common place with practitioners.
As you may expect being in the States there was a great focus on women’s soccer, with talks that included prominent National Team Sport Scientists Naomi Datson (UK), Dawn Scott (USA) and Helena Andersson (Sweden). It is clearly an exciting area and a time when focus and research in the women’s game is growing. I hope they can learn from the mistakes and dead ends of research previously undertaken in men’s soccer and not end up travelling the same path. There was much debate surrounding velocity bands for example (do you use same thresholds as men’s soccer and if not what?) and a suggestion of generating a consensus on banding across the women’s game. A lot harder said than done of course but time will tell if this can be achieved.
There were a number of standout oral presentations led by English or English based practitioners (no bias of course!) Ric Lovell presented his case for Nordic exercises to be carried out after training (or separate to) rather than before as laid out in the FIFA 11+. Performing Nordics before training did increase subsequent sprinting performance (reduced antagonist activation?), this was associated with an increased injury risk demonstrated by decreased eccentric hamstring peak torque.
With two practitioners from Manchester United’s Senior Team presenting (Robin Thorpe and Paulo Gaudino) you can be forgiven for expecting expensive, high tech research. Despite their access to all the tools and toys it was great to see them both present their research on subjective markers; well being and RPE respectively. For example, Robin showed the perceived ratings of wellness were sensitive in daily fluctuations in training load across a standard week, whereas physiological markers of post exercise heart rate (recovery and variability) were not. These are tools that everyone in the audience can apply regardless of their setting and budget.
This was a view supported by Aaron Coutts with the closing invited speaker session (apparently saving the best until last according to Terry Favero). Aaron stressed you must try to forget the silver bullets in black boxes (his AFL side had ‘wasted’ 25k US Dollars on inconclusive blood marker research last year) and use simple tools properly. He demonstrated the use of subjective markers of sRPE and well being questionnaires according to Impellizzeri et al’s (2005) model to monitor two key aspects; was training carried out as planned and how did the players respond. Importantly it is not to control the coach and tell them what they can/can’t do but to measure the response and report back who is or isn’t coping. There were nice examples of how you could present this data in the applied setting; relating training load to below/above/same as match intensity, individual traffic lighting and actual load with projected load.
With reams of abstracts and posters available I think we must try to always ask what difference the research is making to the game of soccer. There is an endless potential for research commentating on the game but what is the application. We could count the number of blades of grass on different soccer pitches… That does not mean we should! Dawn Scott of USA Women’s Soccer put it perfectly in that she is ‘a non believer in measuring something just because’. Similarly in his keynote author Rasmus Ankersen suggested we are answering lots of questions but no one is asking them!
There were loads of other talks that are not highlighted here as well as presentations on other areas of performance including talent identification, pedagogy, psychology. The organizers have made the abstract book available on their website (http://wordpress.up.edu/wcss2014usa/submit-an-abstract/) and is well worth a look to see the whole array of research on offer.
The conference bandwagon moves onto the Seattle Sounders Sport Science weekend (@SSFCSpSci) but my brain needs a rest for the remainder of the off season!