How Important is Fitness?

Very few coaches or players would argue that fitness is not an important part of the game. Fatigue during a match leads to a whole host of problems that lead to poor play. Slowed sprint speed, loss of technical skills, poor decision making and lethargy are all markers of a player who lacks fitness. But what kind of fitness is important? In broad terms, one can consider the ability to sprint and exercise at a high-intensity for a short period of time indicative of anaerobic fitness. On the other hand, the ability to move continuously over the course of a 90 minute match is considered a marker of aerobic fitness. How do these aspects of fitness influence the player’s ability within a match? Is one more important that the other? Researchers in Serbia and Croatia addressed these questions a newly published study. They found that both aspects of fitness are critically important to the performance of players during both the attacking and defending phases of the game.

The investigators examined a group of male, U-14 players, all members of an elite junior club. All were experienced players having had at least four years of soccer training. The design was to compare measures of anaerobic and aerobic fitness to the player’s technical and tactical abilities.

Anaerobic fitness was evaluated using a battery of exercise tests including a single sprint, repeated sprints, and 300m run tests. Aerobic fitness was evaluated by the Hoff test and a multi-stage shuttle run.

Player soccer skills (technical and tactical) were evaluated by a panel of soccer experts including national and international senior coaches and players. During a competitive 11v11 match, this panel judged how players performed during transitioning and positioning during both the attack and defending. Some of the skills included passing, ball control, shots, pressuring, assisting, and preventing shots as well as positioning, “off the ball” movements and the ability to play multiple roles.

The results showed that in the defending phase of the game, 37% of the variability in player performance was due to anaerobic fitness and an equal contribution of aerobic fitness.  That leaves  about 25% due to other factors.  As for the attacking phase, variability on performance was due to 32% anaerobic and 26% aerobic. In short, both anaerobic and aerobic fitness are equally important contributors to the player’s ability to attack and defend.

Over the course of a match, players routinely transition from low intensity jogging or running to high intensity sprints. Given that youth players are expected to cover distances up to five miles per game, and they are required to perform more than 1000 sprints, stops, starts, changes in direction and jumps, it is not surprising that both anaerobic and aerobic fitness are nearly equally important contributors to success.

The physiological demands of soccer are quite complex. In terms of energy cost, most consider it a hybrid sport, exacting a unique blend of energy demands. For this reason, the investigators stress the idea that successful players must be multi-dimensional in terms of fitness. Players need the ability to exercise continuously for long periods of time (aerobic). They also need the ability to sprint and perform multiple, high-intensity bouts with minimal recovery time (anaerobic). One characteristic without the other may prevent them from achieving peak performance. Accordingly, the researchers further emphasize that given this strong link between fitness, technical skill and tactical abilities, coaches should implement all-round fitness training. Such training should include drills and activates that tax both the aerobic and anaerobic energy systems.

Back to the original question, “how important is fitness?” According to this study, the answer is “very important”. Both aerobic and anaerobic fitness are key contributors to overall soccer performance. Thus, training both aspects of fitness is critically important in developing a successful player.

Reference:

Sporis G, Milanovic Z, Trajkovic N, Erceg M, Novak D (2012) Relationship between functional capacities and performance parameters in soccer, Journal of Sports Medicine and Doping Studies, S2, doi:10.4172/2161-0673.S2-001

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A Look Back: Diet and Soccer Performance

Nearly every week, at least one new study focused on diet and soccer performance is published. Researchers continue to learn more about specific dietary components and their effects on fitness, technical skill and mental focus. They also continue to understand the physiological, cellular and metabolic changes that link diet and performance. Back in 1973, David Muckle of the Radcliff Infirmary in Oxford published one of the first studies on how diet affects soccer performance. He found that performance was improved by drinking glucose syrup prior to the start of the match. . As they say, it’s difficult to know where you are going if you don’t know where you’ve been. In this case, it’s often helpful and quite interesting to take a look back at what was found nearly 40 years ago.

At the time of the study, researchers understood that high carbohydrate diets and glucose supplements improved work output, as well as cycle ergometer and treadmill exercise. Since soccer has an endurance component, that information suggested that glucose might also improve player performance. However, that idea had not been investigated. Thus, Dr. Muckle decided to study the relationship between carbohydrate supplementation and team performance.

Over the course of a season, a single team trained to exhaustion in Thursdays. On Fridays, training was light followed by a high carbohydrate meal. On Saturdays (match days), the glucose syrup compound containing mineral salts was consumed 30 minutes before kick off. The team played a total of 40 matches. Twenty were played after drinking the glucose syrup while the other 20 served as the control condition. For each match, the numbers of goals scored and allowed during 15-minute intervals were recorded. Also, blood samples and movement patterns of selected players were noted.

The glucose syrup solution contained 420-450 kilocalories (or calories) in a 46% solution. For comparison, a 20oz bottle of Gatorade contains 130 kilocalories in a 6% solution. So, the test drink used in this study contained a considerable amount of energy and was likely quite thick.

Dr. Muckle found that during matches when the glucose was consumed, there was a steady increase in goals scored in the second period and a decline in goals allowed (see the figure). In the final 15 minutes of the glucose matches, more than twice as many goals were scored compared to the control matches and almost zero were allowed. This probably resulted from more scoring opportunities created under the glucose condition.

As expected, glucose syrup ingestion prevented the decline in blood glucose that occurs over the course of the match.

There are a few questions about the study. Whether or not the conditions were “blinded” is not mentioned. So, the effects of the glucose syrup could be a placebo effect. Also, it is not clear if Dr. Muckle tried to insure that the quality of the opponent was randomized. That is, was the glucose provided equally for matches against both weak and strong opponents?

Despite these questions, this remains a very unique and important study. It is a very simple and straightforward look at how diet affects performance on the pitch. Clearly the most important marker of a team’s performance is the score line. In this regard, a high calorie, carbohydrate supplement provided to a team 30 minutes prior to a match, resulted in more goals scored and fewer goals conceded. Thus, it was effective.

Dr. Muckle concludes his paper with some practical suggestions for the player, suggestions that hold true today. Training should be tapered off 48 hours before the upcoming match. The athlete should rest and eat high carbohydrate meals. The pre-match meal should be light, also high in carbohydrates. Finally, before the start of the match, a carbohydrate supplement should be consumed.

Since 1973, we have learned more about the relationship between nutrition and soccer performance. We also understand the role of carbohydrate supplements in exercise. Diets high in carbohydrates lead to better technical and tactical performance as well as delay exhaustion. We also know that not only do supplements affect muscular performance but there may be a psychological improvement too. But the take home message from David Muckle’s early study remains - carbohydrates are a critical component of the player’s diet that can lead to better performance on the field.

Reference

Muckle DS (1973) Glucose syrup and team performance in soccer. British Journal of Sports Medicine, 7: 340-343.



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Executive Function: The Creative Side of Elite Soccer

When identifying talent and potential success of soccer players, the focus in most often on physical and technical attributes. Speed, size and ball skills often dominate the evaluation process. But what about the mental side of the game? Does a player’s ability to think predict his or her future success? The concept of executive function describes cognitive processes that regulate both thought and action. These processes include planning, problem solving, creative thinking, use of feedback, and cognitive flexibility (quickly altering the plan of action). In a sport such as soccer, players must continually take in large amounts of information, process and assess the situation, rely on past experiences to determine a plan of action. He or she must also remain flexible to unfamiliar situations and new opportunities that arise. Add to that, the plan of attack must be formulated, executed and revised in a matter of milliseconds. This suggests that a high level of executive function would benefit the player. Researchers in Sweden looked at this concept in top-level players. They found that this psychological characteristic is an important predictor the success of these players.

The study compared male and female players from the Swedish professional leagues. Players who played in the Allsvenskan (first division national league) were compared to players from two lower division leagues (Superettan and Division 1).

All players were given several psychological tests designed to measure executive function. Specifically, they were administered the Design Fluency test. This is a “hand and pen” test that measures multiprocessing, creativity and cognitive flexibility. During this test, players were presented with various arrays of dots. They were then asked to find as many possible was of connecting the dots into a square using a single line. The goal is to find as many different combinations as possible within 60 sec.

The results showed that the average score for all players was above that of the general population, indicating that soccer players excel in executive function. In fact, the Allsvenskan players’ scores placed them in the top 5% of the general population. The researchers also found that both male and female players from the Allsvenskan scored more than 15% better than their counterparts from the lower division leagues. This lead the researchers to conclude that executive function is an important characteristic in top-level soccer players and this trait may predict future success of players.

One must take into account that this study is a snapshot of two groups of players. Thus, it is difficult to imply cause and effect. Does higher executive function make for a better player? Or, does playing at a high level improve executive function? Many feel that executive function is relatively stable throughout life. Somewhat like IQ, it is a genetic gift, one that can be improved but only to a small extent. And executive function training usually involves a fairly intense program. Thus, it is most likely that high executive function influences soccer performance rather than vice versa.

The SSO has addressed the importance of decision making previously. Two years ago, elite Dutch players were found to excel in characteristics of positioning and deciding (link). Self-evaluations of tactical abilities showed that elite players were better able to comprehend tactical situations and translate their decisions into actions than were more novice players. The results of the present study suggest that this ability does not necessarily arise from the elite player’s familiarity with the game. Rather it is more of an innate characteristic of being able to critically analyze a situation and arrive at creative solutions to complex problems. That is, elite players think more creatively which leads to better decision making.

For many coaches and students of the game, executive function may be a new term but is not necessarily a new concept. Most are amazed at players who play creatively, those who read the game and routinely create opportunities out of nothing. It is something that is apparent when watching a match. Unfortunately executive function may be a trait that is overlooked when identifying talented players. The study’s authors suggest that coaches should look beyond simply selecting potential players should not only include physical capacity, ball control and how well the player performs. Characteristics of executive function, problem solving and creative play may help them determine if a player has the capacity to reach top levels in soccer.

Reference

Vestberg T, Gustafson R, Maurex L, Ingvar M, Petrovic P (2012) Executive functions predict the success of top-soccer players, PLos ONE, 7: e34731.

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Plyometric Training: Effective for Young Players

Training young players can be difficult. Balancing fitness, technical and tactical training while avoiding over-training and injury can be tough. This is especially true for pre-adolescent athletes who do not yet developed the strength, coordination or fitness to handle overly intense training sessions. In the past, many have argued that there are certain types of training that should be avoided in these young players. For example, weight training in athletes younger than 15 was discouraged. However, recent research shows that if done correctly and if properly supervised, weight training can be safe and very effective for young athletes, even for pre-teens. What about plyometric training? Plyometrics can be very intense and place a large strain on joints, ligaments, tendons and muscles. As a result, it is not generally advised for young players. However, a new study conducted in Greece shows that pre-adolescents respond very well to plyometric training. Including these exercises as part of soccer training can improve strength, speed and power as well as soccer performance.

The study focused on 45 pre-adolescent, male soccer players. One of the unique aspects of the study was that the investigators used the players chronological age (average 10.5 years) as well as bone age, testosterone levels and stage of puberty development to define “pre-adolescent”. This way, they avoided having subjects who were much more physically mature than their birthdate suggested.

Approximately half of the players were placed in the plyometric training group. As part of their normal 3-times per week soccer training, they participated in plyometric training twice per week for 12 weeks. The training program was designed to limit stress and the intensity was gradually increased from a low to moderate level (in accordance with previous research). The drills consisted of single- and double-legged hops over low hurdles, lateral shuttles, skipping and footwork (ladder drills). After the first six weeks, the training began to incorporate depth jumps of increasing height. All of the drills were performed on grass to reduce landing stress and the trainers made a point to emphasize proper technique. In all, each training session lasted 20-25 minutes and was performed immediately after warm-up and before regular soccer training. The control group spent their time doing regular soccer drills while the plyometric group trained.

At both 6 and 12 weeks, the plyometric group significantly improved their sprint times (10, 20 and 30m) by approximately 2-3%. They also improved their vertical and long jump performance by more than 20% and their leg strength (back squat) by more than 25%. These changes in strength, speed and power translated into improved kicking distance and performance on an agility test. The control group also showed slight improvement in some of the measurements but the changes were far less impressive compared to the plyometric group. As a further indicator of the plyometric training program’s effectiveness, the researchers point out that nearly all of the participants improved their performance by 12 weeks.

It is important to note that no musculoskeletal injuries occurred during plyometric training. This suggests that if supervised and progressive in nature, plyometric training in pre-adolescents can be safe and effective. Clearly, common sense is needed when using a plyometric training program with young athletes. The program should be progressive, starting with low-intensity exercises before advancing to complex or intense tasks. Soft landing surfaces should be used. Proper technique should be taught, emphasized and mastered before moving from simple exercises to more difficult ones. This means that proper supervision is essential. Lastly, individual athletes should be monitored closely to insure that they are not over training or placing themselves a risk of injury.

It is also important to note a few limitations to the study. First, the design of the study didn’t require the control group to do an equal amount of non-plyometric work. Thus, it is possible that the improvements in the plyometric group resulted from added work rather than plyometrics per se. Second, females were not studied so it’s not clear of young girls would respond as well as the boys. Lastly, the participants in the study were all experienced players. While averaging 10 years of age, all had at least three years of playing experience and trained for 3-4 time per week. Recreational or inexperienced players may not respond or may be more susceptible to injury. Even taking these limitations into account, the results of the training program are significant. And it is likely that if the program were adjusted for girls and les-trained players, improvements in performance would be seen.

It is easy to see how performance changes due to plyometric training probably have important implications for performance on the pitch. Clearly speed, power, agility and kicking strength are important aspects of the game. The ability to jump, accelerate, stop and change directions is essential for success. In addition, plyometrics are an important ingredient in in the newly developed neuromuscular injury prevention programs such as the FIFA 11+. These programs generally combine with balance, agility, flexibility and core training with plyometrics to reduce the risk of ankle and knee injuries. Thus, there may be a preventative medicine aspect to plyometric training.

Given this new study, coaches now have another item in their training toolbox. Plyometric training, if used properly can be used to improve performance in young players.

Reference:

Michaildis Y, et al. (2012) Plyometrics trainability in pre-adolescent soccer athletes. Journal of Strength and Conditioning Research, DOI: 10.1519/JSC.0b013e3182541ec6

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Player Psyche and Injury Risk

Many consider injuries as an accepted part of the game. Despite this, coaches and researchers work together to reduce the risk of players sustaining an injury. Much of the focus has been on external factors such as equipment and playing field as well as internal factors such as fitness. As a result, successful advancements have been made in equipment and training routines. However, psychological issues are sometimes overlooked as a risk factor. Players often cope with events outside of soccer. For some players, these stressors can increase their anxiety level, which can increase injury risk. Two recent studies of Swedish youth and professional players show that these psychological issues are important internal factors in increasing injury risk. The authors of the studies also provide some insight into how coaches may play a role in reducing this risk factor.

The first study focused on high school male and female players in Sweden whereas the second study examined professional players from the Swedish Premier leagues. At the beginning of the study, players completed a series of psychological and personality questionnaires designed to identify characteristics of stress, anxiety, daily hassle and coping. Over the course of the season, injuries were recorded by the team’s medical personnel. The researcher then compared the various psychological traits between those athletes sustained an injury during play and those who did not.

The studies showed that a key predictor of injury risk is a concept called “somatic trait anxiety”. This can be described as long-term stress that results in physical changes. That is, athletes who demonstrate somatic stress anxiety are often chronically anxious and may show physical signs ranging from sweaty palms to muscle tension. Daily hassles were also a factor. For the younger players, trust in the coach played a role in predicting injury. Lastly, poor coping skills also raised the risk of injury in the young players but not the professionals. It is likely that upon reaching the professional level, these highly experienced players have developed effective skills needed to cope with anxiety. Taken together, the researchers found that these factors, especially anxiety, daily hassles and poor coping skills, accounted for about 25% of the injuries sustained.

The source of stress and anxiety for the players may stem from a variety of pressures. For the younger athletes, schoolwork and the pressure to succeed academically as well as social relationships with peers can create anxiety in many athletes. In addition the pressures of playing well can mount. Pressure from parents and coaches along with the desire to be “seen” at college showcase events or to be “identified” by regional or national coaches can be great. These pressures often result in the players dealing with what they perceive as a variety of daily hassles such as interactions with family, friends, coaches and teachers, completing homework assignments, studying for exams and balancing social relationship. The net result of this affects the players focus and concentration on the game. It can also alter the athlete’s physical nature which then affects their play.

The result of stress, anxiety and daily hassles can lead to one of two risky scenarios. The first is a loss of concentration and focus on the game. Losing focus during a match can prevent the player from identifying cues and avoiding risky situations such as a blind-side tackle. The second is more aggressive physical play that creates risky encounters such as an overly aggressive tackle or header. In either case, the player is unable to identify and analyze situations that may put him or her as risk of injury.

The authors of the studies do offer some suggestions to minimize injury risk. First, coaches should consider the athlete as a whole person. In addition to fitness and technical abilities, coaches should pay close attention to their players psyche and look for signs of stress and anxiety. Identify those players who seem to be struggling with life events or daily hassles, those who show physical or emotional signs or stress. Perhaps a day off is needed to restore their focus and balance. Second, help players develop effective coping skills to reduce the level of stress and worry. Creating an open atmosphere where athletes can express their worries, feelings and concerns could be a step in that direction. Third, help athletes learn muscle relaxation techniques to reduce the level of physical anxiety. Muscle tension is a common physical response to stress and anxiety. By controlling muscle tension, injury risk may be reduced. The overall goal is to provide the tools and avenues for each player to reduce or deal with their stress, anxiety and daily hassles in a healthy manner.

The take home message from these two studies is that the psychological profile of an athlete is an important risk factor for injury. Be they a youth player or a professional, anxiety and life stress that leads to daily hassles can cause the player to either respond or lose to focus, both of which can increase the chances of sustaining an injury.

References:

Johnson U, Ivarsson A (2011) Psychological predictors of sport injuries among junior soccer players. Scandinavian Journal of Medicine and Science in Sports, 21: 129-136.

Ivarsson A, Johnson U, Podlog L (2012) Psychological predictors of injury occurrence: A prospective investigation of Swedish soccer players. Journal of Sport Rehabilitation, in press.

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Nutrient Intake of Spanish Youth Players

It is clear that a player’s diet can affect his or her performance on the field. A diet that is high in fat and low and carbohydrates can leave a player lethargic and without enough “energy” to compete at a high level. This idea is backed by years of research both in the laboratory and on the playing field. Despite this, players still do not eat a proper diet. In a new study, Researchers at the Universidad CEU San Pablo in Madrid performed a detailed analysis of the dietary habits of youth players. As with previous studies, they found that the diets of these players lacked the optimal amounts of carbohydrates, fats and proteins.

The subjects of the study were young male players (aged 16-21 years) from a junior Spanish First Division club. All were asked to self-record their dietary intake for six consecutive days (a full week, excluding match day). What makes this study unique is the level of detail and precision in the dietary records. Players were given food record questionnaires as well as food-weighing scales. They were then instructed on how to record both the types and precise amounts of foods eaten during the week. They were also instructed not to change their eating habits but to eat the same foods that they normally eat. After the recording week, food records were analyzed by the research group to determine how many calories were consumed and whether those calories came from carbohydrates, fats or proteins.

This group of subjects was clearly fit. The average body fat percentage was 10.5%, with goalkeepers having slightly higher values (11.8%) and fullbacks slightly lower (9.9%). All positions also scored high on the Yo-Yo test of intermittent endurance, with the goalkeeper slightly less fit.

As a group, these players consumed nearly 3000 calories per day (38.5 cal per kg of body weight or 17.5 cal per lb). This did not vary between field positions but the goalkeepers consumed fewer total calories that the other positions. While energy expenditure was not measured, this amount of calories consumed per day is probably below what is needed to replenish the energy expended on a daily basis (>3500 cal per day).

The analysis of dietary components showed that as a group, these players consumed less than the recommended amounts of carbohydrates and more than the recommended amounts of fat. For trained soccer players, it is recommended that 55-65% of total calories come from carbohydrates and less than 25-30% from fat. In this group of players, only 45% of their calories come from carbohydrate and 37% from fat. Protein intake was also slightly higher than recommended, 17% versus 10-15%. Thus, the macronutrient intake (carbohydrates, fats and proteins) was less than ideal.

The researchers also found that 55% of the players’ calories came from cereals, potatoes, meat, poultry, milk and dairy products. Without taking preparation into account (e.g. fried chicken versus baked), these are all solid choices that should be included in the diet. However, the researchers also found that 25% of calories came from oils, biscuits, sweets, sweeteners, and pre-cooked foods. Since these items tend to be high in fat or high in simple sugars, they are not solid choices and should be limited to far less that 25%. What is more troubling is that only 1-2% of the players’ calories came from vegetables. A lack of vegetables in the diet not only reduces carbohydrate intake but also limits vitamin and mineral intake.

The overall conclusion from this study is that the caloric intake of these players is less than needed and the macronutrient intake (carbohydrates, fats and proteins) is less than optimal. This conclusion has been reached by others and highlighted on the SSO (Article 1, Article 2). Clearly players need to improve their diets. How can this be accomplished? The authors of the study suggest that the answer lies in education. Players need to understand how the composition of their diet affects their game, that a diet high in carbohydrates and low in fats yields peak performance.

Players also need to understand the food selection process. This is often overlooked in many educational programs – the concepts are taught but specifics are lacking. Few players realize what types of foods that they eat on a regular basis and many do not understand how to make proper food choices. For example, using the food records take from the Spanish players, an obvious suggestion is to reduce the amount of sweets and precooked meals eaten as well as foods cooked in oil (fried). These should be replaced by increased servings of vegetables (preferably fresh). Not only would this reduce the intake of fats but increase the percentage of carbohydrates in the diet (as well as add vitamins and minerals). The researchers emphasize that such a focus on the selection of specific foods and behaviors should be the focal point with young players.

Coaches can play a unique role in affecting the diets of young players, specifically players in their early teens. By making players be aware of what types of foods should be eaten and which should be avoided, it may be possible to improve their diets in terms of both total calories and the optimal percentages of carbohydrates, fats and proteins. There is little doubt that will improve performance. More importantly, instilling proper nutritional habits early in the player’s life can carry into adulthood and led to a healthy lifestyle. Thus, nutritional education can have both immediate and life-long benefits.

Reference:
Iglesias-Gutierrez E, Garcia A, Garcia-Zapico P, Perez-Landaluce J, Patterson A, Garcia-Roves M (2012) Is there a relationship between the playing position of soccer players and their food and macronutrient intake? Applied Physiology, Nutrition and Metabolism, 37: 225-232.

Further Reading:

The SCIENCE Behind Soccer Nutrition
The SCIENCE Behind Soccer Nutrition: Diet and Training Journal

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Translating Sports Science at The Huffines Institute

A word of thanks to the Huffines Institute for Sports Medicine and Human Performance at Texas A&M University for featuring the Science of Soccer Online during their weekly podcast. The Director of the Institute, Dr. Tim Lightfoot and I discussed the use of the internet and social media as a way to communicate with coaches and athletes. We also talked about some of the stumbling blocks that lead to the “information gap” between researchers and coaches.

The Huffines Institute is part of the Health and Kinesiology Department at Texas A&M. Its mission is “Facilitating research, application and communication between sports scientists, practitioners and the world”. On their website, you will find a wealth of information about sports science and human performance, presented in a variety of practical formats. What is unique about their site is that it is not just scientists discussing the latest findings. The site also contains pieces written by or featuring coaches, trainers and students. Through the use of short articles, video and audio interviews, blogs, Twitter and Facebook, the Huffines Institute is making headway in moving science out of the lab and onto the field.

The links to the Huffines Institute and our podcast are below. Visit their site often. Read and listen to the latest in sport science research.

Huffines Institute Website

Weekly Podcast with The SSO


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Traveling the Information Superhighway

It is estimated that 50-80% of the American public uses the Internet to obtain medical and health information. A single Google search using the term “soccer” returns nearly 850 million sites. Combining soccer with terms like nutrition, training or injury returns more than 10-20 million sites. While many of these sites are duplicates and news articles, it is clear that there is a tremendous amount of information about soccer available on the Internet. This raises a number of important questions. How accurate, reliable and complete is information posted on websites? Are some sites more reliable than others? Given the emergence of the information age, studies of website content are now being published. In general, these studies examine the quality and completeness of information found on various sites. The results are troubling. For the most part, traveling the information superhighway is littered with potholes. However, there are some bright spots along the way.

A 2010 survey asked more than 300 registered fitness professionals about where they obtain information on obesity (1). A large percentage these individuals utilize textbooks, class notes, journals and workshops. However, a significant portion also use the Internet and mass media. Those professionals without degrees in exercise science were more likely to utilize the Internet than those with formal education.

Unfortunately the information that these trainers find is relatively poor. A survey of physical activity sites found that less than 2% are considered accurate and 78% are characterized as having low accuracy (2). The researchers conclude that the quality of physical activity information found on the Internet is “dismal”. As a result, many fitness professionals may be utilizing and promoting inaccurate information about exercise training.

The same can be said for nutritional information found on the Internet. Commercial and sponsored sites could account for 80% of the visits and time spent seeking nutritional information (3). That is, Internet users are more likely to use websites that have a commercial investment and promote their product or service. Of these, only 31% have purely correct information. The worst sites are commercial site that contain articles written by “expert” journalists, professionals who write “scientific” articles but have little or no formal training in the medical or health field (3). Articles are often written in an attempt to entice readers to purchase a product rather that to educate them. News sites or sites featuring “news” articles about nutrition also provide questionable information. The investigators specifically mention sites such as Yahoo and MSN as publishing inaccurate or misleading articles.

While accuracy is a key problem, omission also raises concern. That is, the information is often incomplete and unable to answer the questions raised by readers. An example of this is found in a recent survey of sites focused on asthma (4). Researchers found that while many sites contain accurate information, less than 9% provide comprehensive information on the educational concepts provided by the National Heart, Lung and Blood Institute. That is, critical information was omitted. A second potential problem found is the owner of the website. Sponsored sites (those with a commercial interest) or those owned by a single individual are the least accurate and least comprehensive. Sites sponsored by governmental organizations (such as the National Institutes of Health) and professional organizations (like the American Lung Association) provide the most accurate and most complete information.

The problems obtaining accurate and complete information from the Internet are highlighted in a 2010 study (5). The investigators performed Google searches to answer five common child-health related questions. These questions ranged from MMR vaccines to infant sleeping positions. They entered search terms for each question then analyzed the first 500 sites that appeared on the search results.

Of the websites surveyed, 39% gave correct information, 11% gave incorrect information and 49% did not answer the question at all. Governmental sites (those ending in .gov) tended to be the most accurate. Educational sites (.edu) were the second most reliable. News sites provide correct information slightly more than half of the time and none of the sponsored sites surveyed provide accurate information. In particular, sponsored sites suffer from glaring conflicts of interest with many offering products or services that did not conform to sound medical advice.

From these studies, four trends emerge regarding health, nutrition and exercise information posted on the World Wide Web. First, be wary - many websites do not provide complete or accurate information about health conditions or treatments. Many are inaccurate and most suffer from a problem of omission. That is, the lack of information is as problematic as accuracy. Second, articles authored media experts can be unreliable in terms of accuracy and completeness. Most lay authors are not trained in exercise science, nutrition or injury management biology. Complex health issues such as these should be addressed by someone who is an expert in the field rather than someone who is an expert writer. Third, commercial and sponsored websites are rife with conflicts of interest. The problem here is that it is very difficult to determine if the information provided is accurate or if it is designed to entice the reader to purchase a product or service. Many times, misleading information can appear to be sound advice. Sponsored sites should not be used for advice on training because their primary goal is commerce, not necessarily improving performance.

Is there hope? How can one go about finding credible and complete information about issues like soccer, diet, training and injury prevention? The most reliable sites are governmental and educational (typically ending in .gov or .edu). A number of universities have sports science centers that regularly post well-researched information about improving performance and avoiding injury. For example, the Soccer and Health Research Project at the University of Copenhagen has an excellent site that presents soccer-specific information. Professional organizations (not advocacy groups) are also provide sound web-based information. The American College of Sports Medicine’s Access Public Information website provides a number of excellent resources that coaches and players can use. Their sites provide accurate information and the information provided is thorough and complete. The articles are either written by or thoroughly reviewed by experts in the field rather than a copy editor. Likewise, FIFA and the FIFA FMARC group provide excellent information. The advantage of these sites is that they do not suffer from conflicts of interest. Their goal is to provide unbiased, educational information, not to sell a product or sway an opinion.

It is also important be skeptical and look for multiple points of view. It is also important to ask some simple questions when reading information posted online. First, what is the goal of the article? Is the objective to promote a product or to educate the reader? Second, ask who is writing the article? Is the author trained is the topic? Expert coaches are excellent resources for coaching information such as tactical formations, motivating players, etc. However, they may not be the best experts on issues such as supplement use or injury prevention. Likewise, scientists can explain what research says about diet, training and injuries but they may lack context or a sense of how research findings fit into the game. Often considering both a coach’s and researcher’s points of view give the best answer. Lastly, consider what the information is based on. Is the article simply the author’s opinion or is the info based on credible research? Opinions can be biased and sometimes wrong. Look for articles that provide references or list additional resources.

The bottom line, surfing the web for information about soccer, diet and exercise is a case of “reader beware”. The search for accurate information can be difficult. It is a process that must be carried out with care. However, by looking in the right places and asking a few questions, information that is accurate and complete as well as useful to the player and coach can be found in the World Wide Web.

REFERENCES

Stacey D, Hopkins M, Adamo KB, Schorr R, Prud’homme D (2010) Knowledge translation to fitness trainers: A systematic review. Implementation Science, 5: 28.

Bonnar-Kidd KK, Black DR, Mattson M, Coster D (2009) Online physical activity information: Will typical users find quality information. Health Communication, 24: 165-175.

Ostry A, Young ML, Hughes M (2007) The quality of nutritional information available on popular websites: a content analysis. Health Education Research, 23: 648-655.

Meadows-Oliver M, Banasiak NC (2010) Accuracy of asthma information on the world wide web. Journal for Specialists in Pediatric Nursing, 15: 211-216.

Scullard P, Peacock C, Davies P (2010) Googling children’s health: reliability of medical advice on the internet. Archives of Disease in Childhood. 95: 580-582.

NOTE

This article was extracted and modified from the new book, Questioning Research, recently published by Jay Williams.

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More Evidence Supporting Injury Prevention Training: Cost Effectiveness

Over the past years, the SSO has posted several articles about neuromuscular training programs designed to reduce the risk of injury. We have been especially concerned about preventing non-contact injuries to the anterior cruciate ligament (ACL) in female players. An ACL tear can be personally devastating to the athlete and result in significant financial costs. Fortunately, the overwhelming consensus is that neuromuscular training programs are highly effective in reducing risk factors as well as occurrence of ACL injuries. A new study by researchers at Northwestern University and the Children’s Memorial Hospital in Chicago trained urban-area, high school basketball and soccer coaches in using a neuromuscular warm-up program. They found teams that using the program substantially reduced injuries to both the knee and ankle. What is unique about this study is that for a small financial investment in training coaches, a large return in injury prevention was realized.

The study was conducted in the Chicago public school system. This is an urban school district that enrolls predominantly low-income students. This is an important aspect of the study as the investigators point out that these schools and athletic teams often have erratic practice conditions (times, equipment and facilities), no athletic trainers on staff and access to health care is lacking for most of the players. Given this, it is clear that the athletes in this school system could benefit greatly from a program designed to reduce the rate of injuries.

All of the 258 head girl’s soccer and basketball coaches in the school district (varsity, junior varsity, sophomore and freshman teams) were contacted and asked to participate in the study. Of those, 95 coaches (37%) representing 111 teams and almost 1500 athletes agreed to participate. The coaches were then randomly divided into control and intervention groups.

The coaches in the intervention group attended a 2-hour training session where they were instructed on how to use the 20-minute neuromuscular warm-up program. A similar program mentioned on the SSO is the FIFA 11+. They were taught the specific exercise that should be used before each practice as well as before games. They were also taught how to distinguish between correct and incorrect form and how to use verbal cues to encourage proper form. Each coach also received a DVD with narrated videos of the exercises, a laminated card for use on the field or court and printed educational materials about knee injuries and neuromuscular training. The compliance rate was very high. The coaches in the intervention group reported that they used the program at 80% of their practices.

The control group coaches received no training in injury prevention and simply went about coaching their teams as done previously.

All of the coaches were asked to complete weekly injury reports. In addition, the researchers met with the coaches and athletes to discuss injuries and to determine the type of injury and how the injury occurred. The investigators were interested in non-contact knee and ankle injuries and whether they were acute (due to a single event) or gradual-onset (developed over the course of several days). No additional information or encouragement to use the warm-up program was provided to the coaches of the intervention group.

The effectiveness of the warm-up program was impressive. The intervention group experienced a 65% reduction in gradual-onset injuries a 56% reduction in acute injuries. Ankle injuries were reduced by 66% in the intervention group. In addition, all athletes sustaining an ACL injury that required surgery were in the control group.

Overall, a 20-minute neuromuscular warm-up program, used prior to training reduced the rate of non-contact knee and ankle injuries by almost two-thirds.

An interesting aspect of the study is the cost effectiveness of the program. The investigators report that the cost of training each coach and providing him/her with a DVD and printed materials was $80 per coach ($4 for each soccer player). The return on this investment was a substantial reduction in medical costs used to treat knee and ankle injuries. For example, using data for ACL tears, for every 11 soccer coaches trained, one ACL injury could be prevented. To put that into perspective, a 6-team high school league could invest $960 towards training 6 varsity and 6 junior varsity coaches in neuromuscular injury prevention (12 X $80). That investment could result in one less torn ACL during the upcoming season. That doesn’t seem like a big impact, but given the costs of ACL surgery and rehabilitation, it translates into a savings of $17,000 to $25,000 in medical costs. Add to that, the personal costs associated with recovery and the increased risk of developing knee osteoarthritis later in life, the total cost savings could be considerable.

It should also be pointed out that this study examined injuries during a single school year or a single season. It seems reasonable that coaches who are trained in the warm-up program would continue to use it during the following seasons. Thus, the cost effectiveness becomes even greater. For example, over a four-year period, the medical cost savings on ACL ruptures alone could potentially approach $100,000. If the costs of other injuries such as ankle and knee sprains are considered, there could be a tremendous return for less than $1000 invested in prevention.

This notion can also be extended to local soccer clubs. Taking into account both recreational and competitive programs, a large club could easily enroll 100-150 high school aged girls. Thus, for a small financial investment in training coaches on injury prevention, there is the potential of lowering knee and ankle injuries by nearly two-thirds as well as reducing health care costs for a number of young female athletes.

In a follow-up commentary, clinicians at the University of Wisconsin at Madison point out that there has been a large increase in the number of for-profit sports performance-training programs available to young athletes. These programs typically emphasize performance but the types of exercises used (strengthening, balance, plyometrics flexibility and agility) mimic the components of a comprehensive neuromuscular injury prevention program. The costs of these programs can range from $100-200 per month or $20-50 per session. This is clearly out of reach for low-income families and young athletes such as those in the Chicago public school system. Thus, a low-cost, school-based training program could provide athletes from low-income families much needed access to injury prevention. Recall that athletes in urban school systems may not have access to athletic trainers. Also, financial situation may prevent them from seeking proper evaluation and treatment by a medical professional. Given this, it is easy to see the potential benefit of such a program in such a population of athletes cannot be underestimated.

The authors of the commentary also point out that more coaches and administrators might be more interested in injury prevention if the program was repackaged as a sport enhancement program. After all, “we play to win the game” and coaches are often more keen to work on sport-specific skills than injury prevention. There is scientific support for this marketing idea. Multiple studies show that neuromuscular training designed to reduce injury risk also improves performance in soccer players as well as volleyball, basketball and tennis athletes. Thus, emphasizing that a neuromuscular training program could improve match performance might entice more coaches to make it a part of their regular training session.

The evidence continues to mount. Neuromuscular training programs are successful in reducing the risk of knee and ankle injuries. In addition, they have the added benefit of being both cost-effective and improving performance in the field or on the court.

REFERENCES

LaBella CR, Huxford MR, Grissom J, Kim K-Y, Peng J, Christoffel KK (2011) Effect of neuromuscular warm-up on injuries in female soccer and basketball athletes in urban public high schools. Archives of Pediatric and Adolescent Medicine, 165, 1033-1040.

Brooks MA, McGuine TA (2011) Translating cost-effective injury prevention research into sustainable change on the playing field. The youth injury epidemic. Archives of Pediatric and Adolescent Medicine, 165, 1050-1049.

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What Separates the Professionals from the Amateurs?

Talent identification in youth soccer is an ongoing debate among the coaching community. What characteristics separate those players who will succeed at the next level from those who will struggle? Factors such as physical size, speed, fitness and technical ability are all important attributes of success. But how important? Many coaches also consider the ability to “read the game” as a critical trait. That is, “off-the-ball” skills are needed to be successful. Researchers at the University of Groningen in the Netherlands looked at this later concept as a predictor of future success. They found that the tactical ability of “positioning and deciding” is a key factor determining which players will reach the professional level and those who will not.

The study focused on elite youth players from Dutch premier league clubs who trained with their club’s talent development program. The authors note that the players’ level of performance placed them in the top 0.5% of all other players at their age. Bottom line - these were highly talented youth players preparing to play that the professional level.

At 17-18 years of age, the players were given the Tactical Skills Inventory for Sports (TACSIS) survey. This survey asks players about their knowledge of the game as well as their confidence in executing specific tactical actions. The goal is to determine their knowledge, decision-making and execution abilities performed during a match.

The players were later tracked into adulthood. At that point, they were divided into two groups based on their adult performance – those who played on a professional team (Premier or national league) and those who played for an amateur club.

The investigators found that the knowledge of the game did not differ between the players who reached the professional level and those who did not. However, those players who scored highest in the area of “positioning and deciding” as a youth player were almost seven times more likely to reach the professional level that those who scored lowest. This was especially true for the midfielders. Even though all of the players had more than 10 years of training and were some of the most talented players in the Netherlands, half of them did not reach the professional level. What separated the professional from the armatures was the ability to make correct decisions and position themselves correctly on the field.

The authors argue that tactical skills involve both the ability to decide the right action as well as the ability to execute it. That is, being able to make the right decision does not always translate into being able to carry out the right maneuver. This component is what the investigators called “positioning and deciding” and what they found to be highly important for success. For example, players may all understand what to do strategically when shifting from a 4-4-2 to a 3-4-3 system. The may also have the technical skills to execute it. However, it is the ability to put that strategy into play during the course of the match that separates the truly talented players. Positioning oneself in the right place making the right decision is essential. That is, seeing the making the correct run or playing the correct ball separates the professionals from the amateurs. In fact, the authors suggest that it may be impossible for midfielders who lack this ability to ever succeed as a professional player.

This study focused on players in the Dutch youth system that trained at the highest level. So, it is not clear if the results are applicable for identifying success at other levels. For example, does positioning and deciding ability determine which US youth players will be successful at the college level? This study suggests it might but more research is needed. Nevertheless the investigators stress that coaches should pay attention to the concept of positioning and deciding when evaluating and training young players. Given that this characteristic impacts future success, fostering that ability is essential in developing young players into successful adults.

References

Kannekens R, Elfernik-Gemser MT, Visscher C (2011) Positioning and deciding: key factors for talent development in soccer. Scandinavian Journal of Medicine and Science in Sports, 21: 846-852.

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