Feature: Football / Soccer
No.47
May 2006
 
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Science and Football in an Applied Context
Thomas Reilly
Inigo Mujika

 

Abstract
The study of Science and Football has become a viable area of academice work, reflected in the growth of conference communications and sports science support systems. This development is exemplified in different countries in Europe and across the world. Sports science in an interdisciplinary form is now an essential element in preparing teams for success, embracing both domestic league competitions and tournaments such as the World Cup.
Key Words: AIS, La Liga, match analysis, Premier League

Background and Introduction
Contemporary association football (soccer) at a professional level is characterised by a more systematic approach towards preparation for play than was traditionally employed. Players, manager and coach now typically have the support and guidance not only of medical staff and physiotherapists whose primary roles are focused on injury management and treatment but also the access to scientific personnel. These “science support” staff may include physiologists, psychologists, nutritionists and performance analysts; indeed some top clubs have called on the services of vision scientists and lifestyle counsellors to help their players. These support systems have also been employed in one form or another by managers of national teams and Football Academy Directors where the focus is on the holistic development of talented young players. There is no single model that is transferable across clubs and countries. In some cases experts are employed by the club in a full-time or part-time capacity to form a “sports science department”. In contrast the club may call on consultancy services of experts at their local University and utilise their professional expertise as and when needed. A further alternative is that existing internal staff are targeted for continuing professional development to acquire the relevant scientific qualifications on a part-time basis. Unless “sports science” services are available, there is now a recognition that the team is at a disadvantage compared to adversaries who are better advised.
The encroachment of science into the area of football is not restricted to the optimisation of performance. Indeed the range of scientific interest in this sport extends from the physical minutiae of participation such as the engineering design of boots to fit the characteristics of the playing surface, to the social milieu inhabited by football fans. Many volumes of academic output have been produced in attempts to dissect the nature of the passion displayed by football supporters and eminent economists have struggled to articulate the business model in the professional game. The study of research topics in the broad canvas of football is now accepted as a valid academic interest rather than a wasteful pursuit. In this article, the milestones in the development of science and football are first described before examples are given of sports science support work in different countries. This theme is further developed by making connections between field-based work in a football context and laboratory-based studies. Some attention is given to research projects initiated by football’s governing bodies, culminating in the identification of issues relevant to performance of international players at major tournaments such as the World Cup.

The Validity of Science and Football
The validity of science and football as a viable academic entity is no longer questioned within academic institutions. The prototype Diploma in Science and Football was instituted at Liverpool John Moores University in 1991 and quickly evolved into a full-blown BSc (Hons) degree. The curriculum is mounted on a solid basis of fundamental sciences, the focus of application being football as opposed to sport in general which characterises “sports science” programmes. There are now similar awards offered at other institutions, for example at the University of Orebro in Sweden. The number of Masters courses directed at the scientific understanding of football has also grown, throughout European institutions in particular. Furthermore doctoral theses on football or directly relevant to it are now commonplace amongst the post-graduate research activities of “sport and exercise science” departments globally.
The need to bridge the gap between the sciences and the practical world of football provided the stimulus for the World Commission of Science and Sports to establish a dedicated steering group. The International Steering Group on Science and Football held its inaugural World Congress on Science and Football at Liverpool in 1987. All the football codes (including Association Football, American, Australian and Gaelic Football, Rugby League and Rugby Union) were embraced in its agenda. The relevant topics were wide ranging, as is apparent form the list shown in Table 1. The Congress is held every four years and leaves a legacy of Proceedings on each occasion (Table 2). The next event is scheduled for Antalya, Turkey during 17th-21st January 2006.
The formalisation of special interest groups for science and football is reflected in the activities of other professional bodies. Since its first Annual Congress in Nice in 1996, the European College of Sport Science regularly holds symposia and workshops on the topic, including satellite symposia in Rome, 1999 and in Salzburg 2003. The First Asian Congress on Science and Football was held at Jikei University, Tokyo, Japan on 2nd-5th November 1995, the 3rd Congress being located at Oman in 2005. Japan has its own highly active professional body, the Japanese Society for Science and Football. The Society held is inaugural congress in 2004, the next event being scheduled for Waseda University, January 6-7, 2007. An International Science and Football Symposium was also held in 1993 and in 2003 in Melbourne, Australia. All these conferences and symposia reflect a growing global interest in the area of football science.
The status of research into science and football has been authenticated by the publication of peer-reviewed work, notable among these have been the Special Issues of the Journal of Sports Sciences devoted to nutrition (1994, 12, Summer 51-550), fatigue (1997, 15 No. 3, 245-381), talent identification and development (2000, 19 No. 9, 655-769), preparation and training (2005, 23 No. 6, 559-658) and an update on FIFA’s consensus statement on nutrition (2006, 24, Special Issue). These publications are complemented by an increasing number of research-based books on different aspects of football.

Governing Body Initiatives
The governing bodies responsible for the game have played a role in boosting the scientific knowledge base in many instances. The international governing body in particular, FIFA, has directed its research programmes towards epidemiological aspects of injuries in the game. Research output has included two special issues of the American Journal of Sports Medicine, and its flagship programme is the F-MARC project (FIFA Medical Assessment and Research Centre), a four-year project devised by the FIFA Committee for Sports Medicine to monitor and analyse football-related injuries. The projects are organised by FIFA’s own research staff in collaboration with key external partners.
The projects supported by FIFA are not limited to investigations of injuries. The consensus statement on nutrition in football agreed by invited experts provided the scientific bearing for changing the rules with respect to availability of fluids for players during the 1994 World Cup. The statement was updated at a meeting convened at FIFA’s Zurich headquarters in August 2005 and published as a Supplement in the Journal of Sports Sciences in 2006. Other areas of investigation include the stresses on referees and the special concerns of Muslim players continuing to train and compete whilst observing the strict rules of Ramadan fasting during the holy month. Lesser awards funded by FIFA include its annual Havelange Scholarship which is open to competition from students worldwide to support a minor research project.
The concerns of the international ruling body about injuries have been reflected in the activities of its constituent confederations and a number of national governing bodies. These programmes have generated data to determine risk factors inherent in the game. The European body, UEFA, demonstrated the success of co-ordinating data from several of the top clubs by using electronic means of collecting data on a repetitive basis. It has also supported the investigation of “under performance” in European players at the 2002 World Cup.
The world of high-performance sport is characterised by a pragmatic approach towards supporting research and football is no different in this respect. Practitioners in the game want immediate answers whereas the research process takes time for its proper planning and execution. Nevertheless there are examples of support from national governing bodies for both short-term and longer-term projects. The Swedish F.A., for example, was sufficiently concerned about overtraining to fund studies of the physiological stresses associated with training camps for young footballers and of a congested competitive fixture list. Both projects contributed to the scientific literature (Malm et al., 2004), findings that are valuable to other workers in the field. Similar examples may be cited for the Football Association which has promoted work on analysis of performance in World Cup tournaments (Taylor et al., 2002), talent identification (Williams and Reilly, 2000) and the impact of the Premier League on styles of play and physiological load on players (Strudwick and Reilly, 2001).

Sports Science Support Work
Personnel engaged in sports science support work may be given a clear brief for their role, although often this is not the case. The role may be quite specific as in match analysis, nutritional guidance, physical conditions and fitness assessment, lifestyle counselling, psychological advice and so on. The sports scientist may also be integrated into a support team and work alongside other professionals. As the input of scientific know-how becomes appreciated, professional clubs and national teams construct their own sports science departments or units. Examples of the structure and scale of sports science support for two European countries are provided in the next section.
The applied work must be viewed primarily as a service to the players and to the club concerned. Nevertheless, this work may provide research output in the public domain, provided data are collected systematically and procedures are thoroughly documented. The information is of general interest when data extend beyond being merely descriptive and can be organised to address a specific question. Repeated monitoring of growth and fitness data on young players can, for example, form a longitudinal or quasi-longitudinal study of interest to paediatric scientists.
Interventions in training can also be structured so that they form an acceptable research design without compromising professional concerns. Such an approach has been helpful in establishing the relative merits of football-specific training and formal training without the ball (see Reilly, 2005). The recording of work-rate in matches can yield relevant outcome variables for interventions whether these are related to training, nutrition or psychology.
The sport scientist can be the vehicle for interfacing novel technology with practice in the football context. This function applies to developments in computer-aided technology for motion analysis, techniques for mental training or physical training, and for monitoring responses to training and recovery. Individual sweat and electrolyte losses have been monitored in top teams to provide tailored nutritional advice to players about their specific needs (Shirreffs et al., 2005). The monitoring of physiological responses to training provided a valuable means of establishing training insights by means of recording heart rate using radio telemetry (see Reilly, 2005). Its use has evolved to one of regulating training intensity, for example when “recovery” is a priority, rather than being merely descriptive of players’ reactions. Football has also been used for evaluating the viability of new technologies, such as monitoring core body temperature using an ingested pill for short-range telemetry during competition (Edwards and Clark, 2006).

The English Premier League
Sports science support systems have been adopted by practically all of the Premier League football clubs and by a number of clubs in the lower leagues. The manner in which sports science support is structured and adopted is not uniform, depending on such factors as the attitude of management, the resources available and the personnel recruited. Some may favour performance analysis and nutrition whilst others prioritise psychology and physiology (strength and conditioning). Typically the gamut of scientific disciplines is covered, the preferences being expressed in full-time and part-time posts and in the allocation between the professional squad and the Youth Academy.
The majority of clubs have installed in their home grounds synchronised multi-camera systems for analysis of performance of players. Formative and summative feedback may then be provided to players following the game. Monitoring of players in training is almost universally practiced, made feasible by the “team system” for recording heart rates. Nutrition is accepted as an essential part of preparation for competition, although few nutritionists are employed in football on a full-time basis. Physiologists are engaged in planning the fitness training programme, the warm-up and cool-down and the assessment of players’ conditioning levels. The sports science support team at one of the Premier League clubs is outlined in Table 3, and includes those dedicated to the Football Academy as well as the top team. Generally the physicians for the top team and the physiotherapists would attend staff meetings of the “department”.
University facilities are sometimes used where field tests cannot provide the physiological information that is necessary. Such facilities include on-line respiratory gas analysis for determination of maximal oxygen uptake (Fig. 1), formal assessment of “lactate threshold” on a motor-driven treadmill protocol, isokinetic dynamometry for assessment of asymmetry or muscle imbalances, and dual-energy-xray-absorptiometry (DEXA) for measurement of body composition. The latter has proved highly acceptable and informative to players for regular monitoring of percent body fat, although the equipment was initially designed for measuring bone mineral density. The result is that a large database is generated for normative purposes which forms a valuable reference for comparing individual observations. It also adds to the longitudinal studies that become possible, such as the influence of seasonal variations.

La Liga: Spain
Spain is widely considered one of the strongest football countries in the world. FIFA world ranking data available since August 1993 places Spain on an average ranking of sixth, and its home first division championship “La Liga” is regarded as one of the wealthiest and most competitive leagues in Europe. The extent to which sport science has contributed to the high performance level of football players in the Spanish system, however, is not well established. The dearth of scientific publications originating from or relating to Spanish football may have to do either with a lack of sport science activity, or with a secrecy regarding methods used by professional football clubs.
To the best of our knowledge, sport science support in Spanish first division football clubs and national teams has traditionally been far from systematic. Athletic Club Bilbao probably pioneered the recognition of the systematic application of sport science principles as a major contributing factor to football performance. The club appointed medical personnel with a recognised sport science background to their medical services in the mid nineteen nineties, and recently created a department of research and development, as a further indication of a true commitment to sport science support for its players, from the youth academy to the professional level.
In recent years, other clubs have also embraced sport science, but have done so to different degrees and through various approaches. Some clubs have followed the approach of incorporating leading sport scientists to their medical and support staff (e.g. F. C. Barcelona, Real Sociedad, Valencia C. F.), whereas other clubs have signed collaboration agreements with local academic, medical or research institutions to obtain specific sport science support as an external service (e.g. C. A. Osasuna, D. Alavés). These services may involve nutrition and nutritional ergogenic aids, physiological testing and monitoring, strength and conditioning, injury prevention and treatment, and/or game analysis. As an example, an investigation was recently carried out by a group of international researchers at Real Madrid C. F. to assess sweat rate and composition during preseason training in a hot environment, which allowed for an individualisation of the players’ hydration strategies (Shirreffs et al. 2005).
Regarding physiological preparation and monitoring, some clubs have performed altitude training camps during the preseason and also during short breaks in the competition calendar in the mid-season (e.g. Athletic Club Bilbao, Real Sociedad), in an attempt to obtain the purported benefits of living and training at altitude, or living high and training low. We are also aware of a systematic biological control programme developed by the medical services of Valencia C. F.
In the injury prevention area, F. C. Barcelona performed some pioneering work in the 2003-2004 season, by implementing an innovative strength and conditioning programme with a strong focus on eccentric exercise with the use of gravity-independent mechanical devices which provide resistance during coupled concentric and eccentric muscle actions, through the inertia of spinning fly-wheels and cones. Some clubs (e.g. Athletic Club Bilbao, Atlético Madrid, F. C. Barcelona) are also experimenting with tensiomyography as an injury prevention tool. This innovative technique allows to detect and analyse separately a player’s superficial muscles’ properties through the observation of contraction time and displacement in response to varying electrical impulses.
A strong focus has also been placed by many clubs on the area of game analysis, as indicated by the fact that eleven of the first division clubs are using the AMISCO PRO game analysis system, which provides a 2D reproduction of the game allowing a precise performance analysis of all the players throughout the match.
Sports science and football at the Australian Institute of Sport
A very different approach to sports science support from the League-based models we described above for the Premier League and La Liga can be found at the Australian Institute of Sport (AIS) football programmes. Football was one of the eight founding sports of the AIS. The AIS runs football programmes for both men and women. The men’s programme was established in 1981 with the broad aims of identifying and developing players for the national under-20 youth team and developing coaches through the Scholarship Coaching scheme. AIS Women’s Football began as an Olympic Athlete Programme initiative and commenced in Canberra in July 1998. The programme offered 20 full-time scholarships to the national team (the “Matildas”) in preparation for the World Cup Qualifiers (October 1998), World Cup (June 1999) and the 2000 Sydney Olympics. The programme is now camps-based (i.e. scholarship players live and train in their respective state academies, but gather for training camps at the AIS several times a year).
Football players have honed their playing skills at AIS with the help of a holistic programme that includes advanced training techniques, sports science and sports medicine, and opportunities for competition. In terms of sports science support, players and coaches benefit from the permanent support of the AIS Sports Science/Sports Medicine (SSSM) programmes. These contribute to their performance development through the integration of the highest standards of provision and research in applied sports science and sports medicine. The so-called Athlete and Coach Services area includes all the service delivery departments of the AIS, which in terms of SSSM comprises: Clinical Services including medicine, physical therapies, strength and conditioning, performance psychology and skill acquisition; and Sport Sciences including nutrition, biomechanics, physiology, performance analysis and fatigue and recovery. Players and coaches have permanent, unlimited access to the SSSM services. In addition to sports science and medicine support, good examples of the football related applied research approach pioneered at the AIS by the late Douglas Tumilty can be found in the sports science literature (Cox et al., 2002; McLean and Tumilty, 1993; Tumilty, 1993).
The AIS also features a National Talent Search Programme designed to help sports identify talented athletes (12 years and older) and prepare them for participation in domestic, national and eventually international competition. The programme utilises information across all disciplines of the sports sciences to identify young athletes with characteristics associated with elite performance. Within this context, a recent experience was carried out to identify and develop potential female football players at a relatively advanced age (Hoare & Warr 2000).

Laboratory based work
Whilst applied sports science has evolved to create its own tools of assessment, such as the creation of field-based fitness tests in a football context questions arising in practice may sometimes be addressed only in laboratory conditions. This link between practice and theory is exemplified in the treadmill protocols simulating the exercise intensity of football that have been adopted for experimental investigations.
Drust and co-workers (2000a) designed an intermittent exercise protocol in which the activities were varied in a systematic manner alternating between walking, jogging, cruising, sprinting and occasional static periods. The sequence of changes could be programmed into a motor-driven treadmill in 22.5 or 15-min cycles with a 15-min rest separating two 45-min halves. The protocols were planned from results of work-rates in matches to induce physiological responses corresponding to observations in real match-play. This simulation of the competitive work-rates has been used to study the effect of pre-cooling the body before starting to play in hot conditions (Drust et al., 2000b), the challenge imposed by match-play on the immune system (Sari-Sarraf et al., 2006), the progression of muscle fatigue during a game (Rahnama et al., 2006) and compare different formulations and administration of sports drinks (Clarke et al., 2005). An alternative protocol used to evaluate the ergogenic effects of a sports drink comprised shuttle running for 75 min at an average intensity corresponding to playing a game, then exercising until exhaustion at % O2 max (Nicholas et al., 2000).
Simulation of situations typical of competition have been used to investigate the nature of decision-making in football and identify those individuals who consistently make good choices. Individuals may be asked to respond to scenarios presented in video clips on large screens in front of them. During the process their eye-movements, ground reaction forces and actions are recorded. This kind of experimental set-up has been used in understanding the behaviour of goalkeeper and striker during the penalty kick and in the anticipation skills of talented young players characteristic of “game intelligence” (Williams, 2000).

The World Cup Player
Playing in a World Cup tournament should arguably represent the pinnacle of a professional footballer’s career. Yet not all players achieve their peaks or play at their best on the occasion of the sport’s greatest showpiece. This “underperformance” has been investigated for players at the 2002 tournament in Korea and Japan in an attempt to explain the lack of success of some European teams, notably the 1998 champions, France.
It appeared that an exhausting domestic calendar can have adverse carry-over effects into the World Cup finals (Ekstrand et al., 2004). Those players with a heavy competitive engagement, both in the national league and in the European Champions League, were most affected. The wear-and-tear associated with competing twice-a-week and the short time between the end of the league competitions and the start of the World Cup left inadequate opportunity for a planned recovery-retraining cycle. Since players from all continental confederations could be affected, this issue of arriving fresh and fit for the World tournament has been a common concern prior to the 2006 World Cup.
Indeed, the lifestyle of the modern professional player can be physiologically taxing. Those with dual responsibility for club and country may have frequent engagements that entail travel across multiple time-zones and to different climates. South American, Asian and Australian players are most affected by the former stress and African players by the latter. Since jet-lag and heat stress both can adversely affect football performance, these players cannot always play to their capabilities. This fact can cause tension between the professional clubs that employ the players and the national associations the players represent.

Overview
Sports science has grown to be both an accepted academic discipline and a valid area of applied professional work. This evaluation is apparent in the context of science and football. Sports science support teams now operate in a football culture which was traditionally hostile to extraneous influences. Scientific knowledge is now utilised to the benefit of top professional teams and youth academies. The governing bodies also play a part by highlighting areas for research and publicising findings. Those with aspirations for their team’s success in major competitions can ill afford to ignore the possibilities that scientific input can ease the way for them to achieve their goals.

Table 1. Themes offered for open communications to the First World Congress on Science and Football.

Congress Themes


Table 2. Proceedings from the World Congress on Science and Football.
  1. Reilly, T., Lees, A., Davids, K. and Murphy, W. (1988). Science and Football. Proceedings of the First World Congress on Science and Football, Liverpool. London: E. and F.N. Spon.
  2. Reilly, T., Clarys, J. and Stibbe, A. (1993). Science and Football II. Proceedings of the Second World Congress on Science and Football, Eindhoven. London: E. and F.N. Spon.
  3. Reilly, T., Bangsbo, J and Hughes, M. (1997). Science and Football III. Proceedings of the Third World Congress on Science and Football, Cardiff. London: E. and F.N. Spon.
  4. Spinks, W., Reilly, T. and Murphy, A. (2002). Science and Football VI. Proceedings of the Fourth World Congress on Science and Football, Sydney. London: Routledge.
  5. Reilly, T., Cabri, J. and Araújo, D. (2005). Science and Football V. Proceedings of the Fifth World Congress on Science and Football, Lisbon. London: Routledge.
Table 3. Sports science personnel in one Premier League club
Physician
Physiologist
Physical Trainer (physiologist)
Nutritionist
Psychologist
Match Analyst
2
2
3
1
2
2


Figure 1. An England International player is assessed for maximal physiological function on an incremental treadmill protocol.




References
Clarke, N.D., Drust, B., MacLaren, D.P.M. and Reilly, T. (2005). Strategy for hydration and energy provision during soccer-specific exercise. International Journal of Sport Nutrition and Exercise Metabolism, 15, 625-640.
Cox, G., Mujika, I., Tumilty, D., and Burke, L. (2002). Acute creatine supplementation and performance during a field test simulating match play in elite female soccer players. International Journal of Sport Nutrition and Exercise Metabolism, 12, 33-46.
Drust, B., Reilly, T. and Cable, N.T. (2000a). Physiological responses to laboratory-based soccer-specific intermittent and continuous exercise. Journal of Sports Sciences, 18, 885-892.
Drust, B., Cable, N.T. and Reilly, T. (2000b). Investigation of the effect of pre-cooling on the physiological responses to soccer-specific exercise. European Journal of Applied Physiology, 81, 11-17.
Edwards, A.M. and Clark, N.A. (2006). Thermoregulatory observations in soccer match-play: professional and recreational applications using an intestinal pill system to measure core temperature. British Journal of Sports Medicine, 40, 133-138.
Ekstrand, J., Walden, M. and Hagglund, M. (2004). A congested football calendar and the wellbeing of players: correlation between match exposure of European footballers before the World Cup 2002 and their injuries and performances during that World Cup. British Journal of Sports Medicine, 38, 493-497.
Hoare, D.G. and Warr, C.R. (2000). Talent identification and women's soccer: an Australian experience. Journal of Sports Sciences, 18, 751-8.
Malm, C., Ekblom, O. and Ekblom, B. (2004). Immune system alteration in response to two consecutive soccer games. Acta Physiologica Scandinavica, 180, 143-155.
McLean, B.D. and Tumilty, D.M. (1993). Left-right asymmetry in two types of soccer kick. British Journal of Sports Medicine, 27, 260-2.
Nicholas, C.W., Nuttall, F.E. and Williams, C. (2000). The Loughborough Intermittent Shuttle Test: a field test that simulates the activity pattern of soccer. Journal of Sports Sciences, 18, 97-104.
Rahnama, N., Lees, A. and Reilly, T. (2006). Electromyography of selected lower limb muscles fatigued by exercise at intensity of soccer match-play. Journal of Electromyography and Kinesiology, in press.
Reilly, T. (2005). An ergonomics model of the soccer training process. Journal of Sports Sciences, 23, 561-572.
Reilly, T. and Ekblom, B. (2005). The use of recovery methods post-exercise. Journal of Sports Sciences, 23, 619-627.
Sari-Sarraf, V., Reilly, T. and Doran, D. (2006). Salivary IgA response to intermittent and continuous exercise. International Journal of Sports Medicine, 27.
Shirreffs, S.M., Aragon-Vargas, L.F., Chamorro, M., Maughan, R.J., Serratosa, L. and Zachwieja, J.J. (2005). The sweating response of elite professional soccer players to training in the heat. International Journal of Sports Medicine, 26, 90-95.
Strudwick, T. and Reilly, T. (2001). Work-rate profiles of elite Premier League football players. Insight: the FA Coaches Association Journal, 4(2), 28-29.
Taylor, S., Ensum, J. and Williams, M. (2002). World Cup 2002 – Korea/Japan: A qualitative analysis of goals scored. Insight: the FA Coaches Association Journal, 5(4), 28-31.
Tumilty, D. (1993). Physiological characteristics of elite soccer players. Sports Medicine, 16, 80-96.
Williams, A.M. (2000). Perceptual skill in soccer: implications for talent identification and development. Journal of Sports Sciences, 18, 737-750.
Williams, A.M. and Reilly, T. (2000). Talent identification and development in soccer. Journal of Sports Sciences, 18, 657-667.


Contact:
Thomas Reilly
Research Institute for Sport and Exercise Sciences
Liverpool John Moores University
Henry Cotton Campus
15-21 Webster Street
Liverpool, L3 2ET
United Kingdom
T.P.Reilly@ljmu.ac.uk





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