Soccer as Preventative Medicine: More Evidence

There is little doubt that playing soccer directly affects one’s heath. The amount of physical activity and the emphasis on proper diet found in competitive soccer clearly reduces the risk and incidence of health-related problems such as childhood obesity. It also seems that the benefits of youth sports carry over to adulthood. Now, more evidence has emerged linking competitive athletics with decreased risk of health problems later in life. Researchers in Turku, Finland have found that participation in competitive sports is associated with reduced odds of developing metabolic syndrome.

Metabolic syndrome is cluster of several risk factors that increase ones odds of developing Type 2 diabetes, heart disease and stroke. These include obesity, elevated blood pressure (hypertension), elevated blood glucose, insulin resistance and elevated cholesterol. Some studies suggest that 25% of the US adult population may suffer from metabolic syndrome. More recent studies indicate that some of these risk factors are beginning to appear in both adolescents and children. Researchers agree that one key strategy to preventing or reversing metabolic syndrome is exercise, physical activity and diet.

In this study, researchers examined a series of surveys administered to Finnish children and youth (ages 6-18). The Young Finns Study asked a wide range of questions regarding health, physical activity, diet, etc. Specifically, the initial survey conducted between 1962 and 1977, asked the kids if they played competitive sports with a sports club less than once per week (non-athletic level), once per week (moderate-athletic level) or more than once per week with regional or national team play (high-athletic level). Because the survey was administered over the course of several years, the investigators could determine which athletes dropped out (played less 3 years) and those who persisted playing three or more years.

The original survey participants were contacted again after they had reached 24-39 years of age. At that time, they were asked about their current health status including several markers of metabolic syndrome (body weight, blood glucose, etc.).

The results showed that 16% of the male non-athletic group had developed metabolic syndrome compared to only 6% of the high-athletic group. In females, the rates of developing metabolic syndrome were lower, but the difference between non-athletic and high-athletic groups was similar to the males. In fact, the odds of non-athletic group developing metabolic syndrome were 3-4 times that of the high-athletic group.

Persistent athletes had lower odds of developing metabolic syndrome than those who played less than three years (drop outs). High-athletic athletes also had lower risk than moderate-athletes. Lastly, being a starter did not affect the risk as long as participation persisted.

This study indicates that participation in competitive youth sports for three or more years is associated with reduced risk of developing metabolic syndrome. Persistence seems to be the key rather than the individual skill level.

There are two reasons why this might occur. First, it is possible that competitive sports may lay the foundation for a healthy lifestyle. Regular exercise and proper diet, both of which lower the risk for metabolic syndrome, may be instilled at a young age. In a study reported earlier on the Science of Soccer Online, researchers found that kids who played sports at an early age remained more physically active later in life (link). So there is reason to suggest that competitive youth sports do in fact develop habits that will keep individuals health through adulthood.

Second, it is also possible that genetic factors and what is called self-selection may be at play. Genetics influences a number of metabolic syndrome characteristics such as blood pressure and cholesterol. It may be that kids who have a genetic make-up that makes them less susceptible to developing these risk factors are the same ones who gravitate towards competitive sports. That is, athletes may not only be gifted in terms of sports performance but also in terms of avoiding metabolic syndrome risk factors.

In either case, this finding has implications for promoting youth sports as part of a healthy lifestyle. It is yet another piece of a growing body of evidence linking youth sports to a healthy adult lifestyle. Soccer clubs can play an important role by providing an avenue for participation in physical activity and by instilling habits that will last a lifetime. These include, engaging in regular vigorous exercise and eating a diet that is high in nutrients and low in fat.

Reference:

Yang X, TElam R, Hirvensalo, Viikari SJA, Raitakari (2009) Sustained participation in youth sport decreases metabolic syndrome in adulthood. International Journal of Obesity, DOI: 10.1038/ijo.2009.171.
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Does ACL Injury Prevention Really Work?

One of the major problems facing female athletes is the risk of tearing their anterior cruciate ligament. Non-contact ALC injuries occur in women at a rate 4-6 times that of males. In addition to the personal costs, the financial costs of surgery and rehabilitation have been conservatively estimated at $1.7 billion annually. The exact reasons why women are so much more susceptible to ACL injuries than are men are still being debated. However, one issue that is clear is that something needs to be done to lower the risk of injury. One solution is the development of various neuromuscular training programs designed to prevent ACL injuries. In general, these programs use strengthening, plyometric, flexibility and balance exercises to enhance knee stability. But, do they really work? Do they actually reduce the risk of injuries in women?

A group of Korean researchers recently addressed these questions. To do this, they examined all of the available research studies involving women, ACL injuries and ACL injury prevention programs. Using these studies, this they performed a meta-analysis of the results. A meta-analysis is a statistical tool whereby the results of many studies are “pooled” and analyzed simultaneously. The goal is to come up with a “consensus” result. This process provides a more comprehensive look at whether or not these programs are effective in lowering the incidence of ACL injury.

Seven key studies were analyzed. All were similar in that they used young female subjects. Some subjects were under the age of 18 while a few studies used college-aged girls. In all, more than 11,000 subjects were included in the seven studies. The seven studies also used what is termed a “randomized control trial”. This means that each study compared a treatment group (received ACL injury prevention training) to a control group (received no prevention training). Also, the subjects were randomly assigned to one of the two groups.

The researchers found that the use of neuromuscular training was very effective in preventing ACL injuries in female athletes. The meta-analysis revealed that the neuromuscular training programs reduced the odds of suffering an ACL injury by 60%. These programs were more effective in young athletes. In adolescents, the odds of injury were cut by 73%.

The researchers also found that using a neuromuscular training both before and during the season was more effective than using the program only during pre- or in-season. The intensity of the program seemed to be an important factor. Programs conducted at practice and supervised by a coach were more effective than a home-based program. Lastly, plyometrics and strength training seems to be a bit more important than balance training. It seems that starting early in a players career may be more effective that beginning later.

Back to the original question; does ACL injury prevention really work? Based on this paper, the answer is a definitive yes. By including neuromuscular training as a part of both pre-season and in-season practice, the risk of suffering an ACL injury can be substantially reduced.

It is important to point out that this study shows that training can reduce the risk of injury. It does not indicate that this type of training will prevent injuries from occurring. Some injuries will occur despite the best training efforts. However, lowing risk will reduce the overall number of injuries that occur on a single team or within an individual club. Thus, improving the odds of avoiding ACL injuries will help a large number of players stay healthy and increase the chances of a successful season.

Reference:

Yoo JH, Lim BO, Ha M, Lee SW, Oh SJ, Lee YS, Kim JG (2009) A meta-analysis of the effect of neuromuscular training on the prevention of the anterior cruciate ligament injury in female athletes. Knee Surgery, Sports Traumatology and Arthroscopy, DOI: 10.1007/s00167-009-0901-2.

For more info on neuromuscular training programs, follow these links:

FIFA 11+

Santa Monica Orthopedic and Sports Medicine Group PEP Program
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Menthol: Fresh Breath and Better Performance?

Exercising in the heat is always a difficult task. Hot environments place a tremendous demand on the cardiovascular and thermoregulatory systems. This typically leads to decreased performance, particularly in sports that last an hour or more. As a result, coaches and players are always searching for new ways to perform in the heat. In a new study, researchers at Manchester Metropolitan University in the United Kingdom report that simply rinsing the mouth with menthol, a common flavoring agent, can actually improve performance during exercise in a hot environment.

The researchers asked nine moderately trained subjects to exercise on a stationary bicycle at ~65% of their maximal capacity. They were told to continue exercising as long as possible while the total duration was recorded. On one occasion, subjects swilled a 0.01% menthol solution in their mouth for 10 seconds after which it was spit out without swallowing. On the other occasion, they swilled an orange flavored placebo drink. They were given the solution every 10 minutes and were allowed to drink as much water as they wanted. All of the bouts were performed in the heat at a room temperature of 34°C or 93°F.

Eight of the nine subjects improved their exercise duration when they swilled the menthol. Total exercise time increased from an average of 58 to 63 minutes. Despite this improvement in performance, there were no differences in the subjects’ body temperature or the amount of energy expended. What seemed to be improved was the perception of their effort. Overall, the subjects felt that that the menthol was “refreshing” and “stimulating”. This resulted in the subjects feeling a reduced sense of effort during the exercise bout, particularly a reduced effort of breathing. That is, breathing felt easier which made the exercise seem easier.

The authors conclude that the improvement in performance was probably due to psychological factors. The menthol may have stimulated some region of the mouth which activated a network of taste- and reward-regions of the brain. The pleasantness of a cool mouth coupled with taste and flavor may have caused the subjects to experience less discomfort as they were approaching exhaustion.

Menthol is an interesting compound. It comes from various mint oils as well as peppermint. When it is applied to the skin, there is a cooling sensation. The same sensation is experienced when taken orally. As a result, many companies include menthol in all sorts of skin creams, foods, mouthwashes, medications and cigarettes. Ben Gay ointment, peppermint candies, and many throat lozenges all contain menthol. Some people report that this cooling effect increases alertness and reduces minor pain. For example, a throat lozenge soothing sore throat pain. So it is not surprising that swilling a menthol drink might reduce one’s perception of breathing during exercise.

There are a few important points to be made about this study. First, and most importantly, the menthol did not actually lower body temperature. The improvement in performance does not indicate that menthol protects against any of the potential problems of exercising in the heat such as dehydration. It remains very important that when exercising in the heat, players drink plenty of fluids and to be aware of heat-related illness and injury.

Second, the type of exercise performed in this study doesn’t really simulate match play. The subjects were asked to exercise at a constant, pre-determined pace and to continue as long as possible. Match play requires players to start and stop and run at a variety of speeds. This means that the reduced perceived exertion caused by the menthol may be specific to the type of exercise studied and may not occur during an activity like soccer. Also, it is difficult, if not impossible for players to drink every 10 minutes during a match.

Despite these drawbacks, the finding that menthol may improve performance is intriguing. While it may not actually combat the physiological effects of exercising in the heat, including it in drinks may have some positive psychological effect. This study also adds to a growing body of research showing that what goes into your mouth may affect exercise. Earlier, the SSO reported that merely swilling a carbohydrate beverage (sports drink) might also affect the central nervous system and improve performance (LINK). These studies suggest that the mouth may be more important than previously thought. It may be more than a simple a passage way to the stomach but a key sensory component of perceived exertion.

Reference:

Mundel T, Jones DA (2009) The effects of swilling an L(-)-menthol solution during exercise in the heat. European Journal of Applied Physiology, DOI: 10.1007/s00421-009-1180-0
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Kudos to the Soccer Moms

By design soccer is an activity that promotes health and fitness. The amount of exercise performed at practice and the emphasis on proper diet directly affects players’ fitness and promotes a lifestyle that influences health well into adulthood. A recent study now suggests that participation in youth sports may have other, unanticipated effects that may lead to an overall healthy lifestyle. Researchers from SUNY Brockport have found that playing sports may have some influence on whether or not high school kids use their seatbelts.

The study analyzed the data found in the US National Youth Risk Behavior Survey. This survey is administered every two years to groups of 9th through 12th graders. For this study, two aspects of the survey were used. The first was a question about seatbelt use when riding in a car. The teenagers were categorized as those who always / mostly / sometimes used seatbelts and those who rarely / never used them. Second, athletic participation was determined by how many high school or club sports each kid participated in. Non-athletes did not participate in any sports, moderately involved athletes played on 1-2 teams per year and highly involved athletes played on 3 on three or more teams.

Of nearly 19,000 students surveyed, 81% reported that they used seatbelts at least some of the time. The results also showed that girls were more likely than boys to wear seatbelts as were younger teens versus older teens. The more interesting finding was that both moderately and highly involved athletes reported more seatbelt use than the non-athletes. In this study, non-athletes were 25% more likely to report that they rarely or never wear seatbelts than were the teens that played sports.

The investigators argue that the differences between athletes and non-athletes may be related to personality types and the need for teens to engage in “risky” behaviors. Sports may provide an alternative to risky behaviors such as not wearing a seatbelt. They also suggest that athletes may avoid risky behaviors out of fear that their place on the team may be jeopardized. They may fear being punished by their coach or parents, especially if the behavior results in a violation of seatbelt laws.

While the researchers may be on to something, they may have overlooked a more obvious reason for the increased seatbelt use among teenage athletes. Seatbelt use is a habit that probably gets ingrained early in life. It seems reasonable that young children who grow up wearing seatbelts will use them as teens. This is where the soccer moms step in. How many parents who drive the team carpool have said, “We’re not going anywhere until everyone buckles up”? Could it be that this insistence on seatbelt use helps kids develop a habit that lasts once they’re driving on their own? Maybe all of those trips to and from practice have the unintended benefit of promoting a healthy lifestyle practice!

Nearly everyone is aware of the importance of seatbelt use. Using a seatbelt is estimated to prevent nearly 16,000 deaths annually and as many as 350,000 injuries. Seatbelt use is perhaps the most important factors in preventing injury and death during an auto accident.

So, to all you soccer moms (and dads): keep up the good work. Pestering your kids to wear their seatbelts may be paying off!

Reference

Melnick MJ, Miller KE, Sabo DF, Barnes GM, Farrell MP (2009) Athletic participation and seatbelt omission among US high school students. Health Education and Behavior, in press, DOI 10.1177/1090198107308377.
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FIFA F-MARC "The 11+" Website

The FIFA and the FIFA Medical Assessment and Research Centre (F-MARC) have recently developed a website dedicated to "The 11+". The 11+ is a warm-up program developed for soccer players designed to reduce the risk of lower extremity injuries (for a discussion of The 11+, click here). The website contains downloads such as posters and instruction cards as well as an collection of videos showing how to perform each exercise. The is an excellent resource for those wanting ot incorperate The 11+ as part of a regular warm-up routine.

Click here to visit their website.

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Where Did All the Freshmen Go?

At some point in their soccer careers, many American youth players dream of playing beyond their high school days and joining a collegiate side. For some this becomes a reality. Each spring those high school seniors sign their National Letter of Intent, solidifying a commitment to a college program. Once the fall arrives, these new freshmen take the field and the next step in their playing carriers. However, in many cases, large numbers of newcomers appearing on college rosters are matched with relatively small numbers of veteran players. In fact, it’s not uncommon for programs to have only a handful of graduating seniors. The discrepancy between freshman and senior classes begs the question, “Where did all the freshmen go?”

To gain some insight into this question, the rosters of the nine ACC men’s soccer programs were analyzed. This conference was chosen because it is arguably the strongest college conference in the US. Nearly all of the ACC programs have appeared in at least one College Cup (the NCAA Final Four) and six of the nine programs have won national championships. The analysis focused on the rosters from 2004 to 2009 seasons. The numbers of players in each class were tallied as was the number of years each player appeared on their program’s roster. Players were classified as first year (freshman), second year (sophomore), third year (junior), fourth year (senior) or fifth year. Red shirt players were classified with their original class. That is, a red shirt junior was classified as a senior. Red shirt seniors were classified as fifth year players.

For all rosters combined, the number of players in each class decreased as they aged. As expected, freshmen occupied the largest percentage of players, 30%. Sophomores accounted for 26%, juniors 23% and seniors 21%. Fifth year players accounted for les than 2%.

The main objective of this analysis was to track the ’04, ’05 and ’06 freshman classes over their four years of eligibility to determine how many played for a full four years. These groups of players should appear as seniors on the ’07, ’08 and ’09 rosters. The results were interesting. For those three classes of athletes, less than half, 47% were rostered all four years. Nearly 25% of them were rostered for there freshman year only. Overall the average number of years played by these freshmen at their original institution was less than three.

There was quite a bit of variability between individual programs. One program retained 100% of its freshman players for their four years of eligibility. On the other end of the spectrum, two programs had four year retention rates of less than 30%.

As for the seniors on the ’07, ’08 and ’09 rosters, 61% were from each school’s original freshmen class. For a typical roster of 25 players, only 3-4 began their senior season with a full three years of playing experience in their program. The remaining 39% of the seniors on the roster entered the program after their freshman year with less than four years of eligibility. Those “transfer” players averaged slightly less than two years of playing experience with their new team.

What about women’s programs? For the nine ACC schools that play both men’s and women’s soccer, more than 80% of the freshmen play a full four years. Also, 94% of the seniors listed on the rosters began their careers at the same institution.

Does this occur in other levels of collegiate play? A quick check of team rosters from other conferences and some Division III programs suggests that the answer is yes. While the exact percentages vary, it is clear that a large number of players start out as freshman but do not complete their four years of eligibility.

Why does this happen? Unfortunately these numbers don’t really answer the original question, where did the freshmen go? The loss of players from an original freshman class is probably a combination of factors. Some such as Charlie Davies and Patrick Nyarko choose to forgo their remaining years of eligibility and pursue professional careers in the US or Europe. For some, this may happen after their freshman year. Other players may transfer to other programs for both athletic and academic reasons. Still others may suffer career-ending injuries or simply decide to give up playing and focus on their academic pursuits. Whatever the reason, it’s clear that many freshman players either end their careers or move on to other opportunities before they eligibility is exhausted.

The bottom line, there is considerable turnover in the rosters of men’s college programs. For the ACC, more than half of the freshman players leave their program before they exhaust their eligibility and some are replaced by others entering the program after their freshman year. If the results are projected forward, one can expect that a large percentage of high school players who sign a National Letter of Intent will not complete their four years of eligibility at that institution. Some will end their college careers early and others will finish playing with another program.
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Are We Stifling Creative Play?

An article posted on the website, Scientific Blogging, describes a talk given by speaker and author Dan Pink. A common belief is that extrinsic motivation in the form of rewards can improve performance. However, scientific research shows that incentivising a problem-solving task may stifle creativity and actually hinder the outcome. That is, the traditional carrot and stick approach seems to weaken problem solving abilities. Could it be that we are motivating players the wrong way? Is the reward system often used in training, limiting the players ability to develop on-field problem solving abilities?

Dan Pink emphasizes several research papers that look at problem solving in people who are offered incentives for their solutions. In these studies, subjects are given a task that requires them to formulate a creative solution to solve a problem. If the subjects are told that they will be rewarded for the fastest completion time, subjects actually take LONGER to solve the problem than when no reward is offered. They become focused on the reward and lose the ability to think creatively. Their reasoning capacity limits how they come up with a solution. If the subjects are left on their own with no reward, their intrinsic motivation drives the problem solving. They are then able to solve the problem in a shorter time period using a more innovative solution. In short, offering an external incentive as a motivational tool seems to prevent subjects from thinking outside of the box, so to speak.

Dan Pink presents this idea in the context of the business world and employees that need to solve tough problems. However, there may be implications for training soccer players. One criticism of US players is that they are not very creative in their play. Soccer requires a considerable amount of problem solving skill. Whether defending or attacking, players must “see the field”, think through a list of possible options, then execute. Only on set pieces can they “run a play”, so to speak. The question then is how to train players to think creatively. How can they be more creative on the field?

Many coaches often use a rewards system during practices. For example, the winners of a small sided match are often given a reward and the losing team suffers a consequence. It’s not uncommon for the losing team to run sprints while the winners take a break. Coaches have long argued that this sort of competition make better players. However, could this carrot and stick approach be stifling the kids’ creativity? In this system, are the players more focused on the incentive rather than solving the problem? That is, are they more focused on not running sprints rather than figuring out how to attack and defend as a team? If this is the case, might they be less motivated to play more creativity?

Compare this to basketball. Playgrounds and gyms are filled with kids playing pick-up games. Here there is no reward for winning or punishment for losing (other than personal pride). The players own intrinsic motivation drives their efforts. They are free to try a wide range of solutions without repercussion. Kids try all sorts of new moves, some of which work and some don’t. The bottom line is that they are thinking outside of the box in an environment that allows them to do so. The result is that US basketball players are the most creative on the planet. Is their success linked to an environment that fosters creativity?

As mentioned above, Dan Pink presents his ideas for the business community, not the sports world. Also, he is talking about motivating adults to solve complex business problems not a bunch of middle school soccer players trying to win matches. Whether this approach is effective with young athletes remains to be seen. However, these ideas are certainly food for thought. They certainly raise questions about how we motivate young kids to become better soccer players.

Scientific Blogging Article (click here)

Dan Pink's Talk (click here)

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NSCA Position Statement on Youth Resistance Training

Part 2: Designing a Program

The NSCA’s Position Statement on youth weight training argues that if children are ready to participate in sports, they are ready to engage in some type of resistance exercise. In Part 1, the safety and benefits of weight training were highlighted. Part 2 summarizes of the authors’ recommendations for designing a weight lifting program for young participants. The overriding importance is designing a program that is age-appropriate, safe, enjoyable and effective in achieving realistic goals.

General Guidelines: The authors emphasize that a medical exam should precede any training to make sure that there are no issues that might prevent the child from exercising. This is common place as a medical exam should precede participation in any sport or strenuous exercise program. The most important aspect of a youth resistance training program is that it be supervised by a qualified trainer who has experience working with children and young adolescents. Proper instruction should be given early on. Kids need to be taught proper weight room etiquette, lifting and spotting techniques, use of machines, and handling weights (medicine balls, barbells, dumbbells, plates, etc). It is important that these instructions be presented in a way that children will understand them. The emphasis should be on a safe environment.

Trainers should discuss realistic goals and outcomes with each participant. These will vary from one child to another so it is important that each kid have reasonable expectations. Trainers should encourage self improvement and focus on individual performance. Discourage competition between participants, especially in beginners. Overall, create an environment where the children enjoy training, look forward to exercising and are excited about their individual gains.

Warm-Up and Cool-Down: There is quite a bit of debate on the effectiveness of warm-ups and what type of activities should be included. Much of this research was performed using adult subjects so the implications for kids are not clear. The authors of the Position Statement argue that a well designed, dynamic warm-up is appropriate for young lifters. It should include 5-10 minutes of hops, skips, jumps, etc. Light jogging or cycling could also be used. The rationale is that dynamic activity will prepare the body for training and help focus attention on the day’s session. After lifting, a cool-down period that includes stretching and calisthenics should be used. This is also an ideal time for the trainer and participants to reflect on the workout and re-emphasize instructions and safety issues.

Types of Exercises: Beginning lifters should start with relatively simple, single-joint exercises and slowly progress to more complex, multi-joint movements. Include body weight exercises, medicine balls and dumbbells. Begin with light to moderate loads and emphasize technique. For example, use 1-2 sets of 10-15 reps with a weight that can be comfortable handled. If technique falters late in the set, reduce the amount of weight. Introduce new exercises early in the workout session when there is less fatigue. At this time, technique can be better emphasized. Even in experienced lifters, new exercises should use the low weight – high rep approach. As technique improves, the load can slowly be increased and the number of reps reduced.

More experienced lifters can train using greater loads and fewer reps (e.g. 3 sets of 6-8 reps). These athletes can also begin to use more complex, multi-joint exercises. Free weight bench press, squats and even power cleans are appropriate in kids who have mastered simple exercises and who have developed both strength and skill. Plyomtrics are also appropriate for these athletes. When using heavier loads and free weights, it is critically important that proper technique be used. This means constant supervision of each lift. IT also means critically evaluating each participant to insure that he or she is ready to attempt more difficult exercises. If the athlete cannot execute the lift with proper technique, reduce the load and focus on skill. Poor technique when lifting heavy loads is a key cause of weight room injuries.

It is also a good idea to vary the types of exercises used. Changing the types of lifts every 4-6 weeks can prevent boredom and keeps kids interested in their workouts. Periodization can also be used with more experienced lifters a part of a pre-season program.

Other Comments: After reading the NSCA’s Position Statement, there are few more points that should be mentioned. First, during the course of training, kids may often develop muscle soreness. When this occurs, scale back on the intensity of the training session or take a day or two off. Also, if the participant experiences any sort of acute or chronic pain, stop training immediately and have them visit their physician. Young athletes should never be encouraged to “work through” any sort of pain or discomfort. It also makes no sense to jeopardize an athlete’s health for short-term gains. Time off to recover from injury is far more important than immediate goals.

Second, progression should not be rushed. Again, a long-term perspective is essential. Over training a 12 year old is of no benefit if he or she risks injury or burned out by age 18. Young athletes have plenty of time to develop strength. There is no need to push someone’s limits for short-term success.

Finally, kids should look forward to a trip to the weight room, not dread it. Create an environment that is safe, effective and enjoyable, especially with young lifters. Be firm enforcing safety issues and weight room etiquette but encourage and praise kids for their efforts and improvements. Remember, resistance training is a life-long activity.

Concluding Remarks: Despite misconceptions and concerns, a overwhelming body of research shows that youth resistance training is both safe and effective. All of the evidence indicates that a properly supervised weight training program can offer numerous health benefits to children and young adolescents. Whether the child is an athlete or simply interested in improving fitness, weight training programs can be designed to achieve individual goals and to promote a life-long enjoyment of physical activity.

Reference:

Faigenbaum AD, Kraemer WJ, Blimkie CJR, Jeffereys I, Micheli LJ, Nitka M, Rowland TW (2009) Youth resistance training: Updated position statement from the National Strength and Conditioning Association. Journal of Strength and Conditioning Research, 23: (supplement 5) / S60-S79.
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National Strength & Conditioning Association Position Statement on Youth Resistance Training

Part 1: Safety & Benefits

The number of young athletes who are lifting weights as part of their training is steadily increasing. In past years, many discouraged weight training in children and young adolescents. This stemmed, in part, from the fear of injury and adverse effects on growth and development. We now know that properly supervised resistance exercise can have a number of positive effects on sports performance, health and psychological well-being. Recently, the National Strength and Conditioning Association assembled seven of the most prominent researchers in the area of youth fitness and resistance exercise. They reviewed 258 individual research studies and prepared a consensus paper regarding the safety, effectiveness, benefits and design of youth resistance training programs. What follows is a brief summary of the NSCA’s Position Statement. Part 1 focuses on safety issues and benefits of strength training. Part 2 addresses designing safe and effective programs.

Safety: For years, some argued that children should not lift weights as it could stunt their growth and injuries to the growth plates of the long bones. In fact, early surveys of sports-related injuries reported a number of injuries associated with youth weight training. However, the vast majority of these injuries were due to improper technique, poor supervision and unqualified trainers; not to weight lifting per se. In weight training studies that were properly supervised by knowledgeable trainers and the children were taught proper technique, very few, if any injuries occurred. This was the case when kids were using machines, body weight exercises, free weights or plyometrics. The key is that the programs must be properly supervised by qualified trainers that provide proper and constant instruction on the techniques and use of equipment. If this is done, the risk of injury is actually very small. As for growth and stature, no study has shown adverse effects on cartilage or growth plates and there is no evidence of “stunted growth”. In fact, resistance training in both children and adults promotes bone health rather than damage. Based on this, the authors of the Position Statement note that “there are no justifiable safety reasons that preclude children or adolescents from participating in a resistance training program”.

Effectiveness: There is little doubt that resistance training increases strength in children and adolescents. Studies show that children as young as 5-6 years of age can benefit from strength training. The strength gains of young children are usually slightly less than what happens in adolescents and adults but they are impressive none the less. Increases in strength of 30-50% have been reported. A wide variety of programs are effective including weight machines, free weights, medicine balls, elastic bands and body weight exercises.

A key difference between children and adults is how they adapt to resistance training and what is responsible for the strength gains. In adults, most of their strength gain is due to muscle hypertrophy (increased muscle mass). Children lack the testosterone needed to increase muscle size. Most of the strength increase that occurs in children is due to neuromuscular adaptations, improvements in skill, coordination and activation of individual muscle fibers. However, this is not to say that children cannot increase their muscle mass. Changes in muscle size are simply not as great as those that occur in adults.

Benefits: There are many potential benefits of youth resistance training programs for both the athlete and non-athlete. All health professionals agree that exercise is essential for proper growth and development. Almost any fitness program can enhance both physical health.
However, weight training offers several unique benefits that aerobic exercise programs may not. Studies have shown that weight training can improve fitness as well as reduce cardiovascular risk factors, strengthen bone, improve motor skill, increase resistance to sports-related injury and improve psychosocial well-being. For the non-athlete, resistance training has been shown to improve body composition by a combination of fat loss and muscle mass gain. It may also lower risk factors for developing diabetes, combat hypertension and improve other health markers. One advantage of resistance training for the non-athlete is that many children find it more enjoyable than traditional programs that involved prolonged aerobic exercise (e.g. jogging). This is especially true in non-athletes. For this reason, recent research studies promote weight training as a way to combat and treat childhood obesity. The changes in body shape, composition and strength can be a psychological boost. Improvements in self-confidence, self-image, mood and overall psychological well being are all associated with resistance exercise. Thus, weight training can be a very effective way to promote health in children and adolescents.

For any athlete, strength and power are essential elements of many sports. It is clear that weight training can lead to improved sports performance. This is especially true in young athletes. However, the benefits of resistance exercise extend beyond performance on the field. One of the more important payoffs of resistance training is that it increases the resistance to sports-related injuries. Improvements in bone health, neuromuscular coordination and muscular strength all make the young athlete less susceptible to injury. This is critically important for non-contact injuries such as knee and ankle ligament sprains and tears. In fact, one study suggests that a well-designed and properly supervised weight training program may reduce the risk of injury by 15-50%. Again, a wide range of programs ranging from free weights to body weight exercises seem to be effective. Thus the increased resistance to injury may be one of the more important benefits of resistance training. Given the high incidence of injuries in some athletes (e.g. ACL injuries in girls), some type of resistance training should be an essential part of any sports training routine.

Conclusions: Based on their examination of the research pertaining to youth resistance training, the NSCA arrives at seven key conclusions. They state that a properly designed and supervised resistance training program:

1. Is relatively safe

2. Can enhance the muscular strength and power in youth

3. Can improve the cardiovascular risk profile in youth

4. Can improve motor skill performance and may enhance sports performance in youth

5. Can increase a young athlete’s resistance to sports-related injury

6. Can help improve the psychological well-being of youth

7. Can promote and develop exercise habits during childhood and adolescents

Given this information, there is no reason why children and young adolescents should not participate in properly supervised resistance training programs. How these programs should be developed is the subject of Part 2 (coming soon).

Reference:

Faigenbaum AD, Kraemer WJ, Blimkie CJR, Jeffereys I, Micheli LJ, Nitka M, Rowland TW (2009) Youth resistance training: Updated position statement from the National Strength and Conditioning Association. Journal of Strength and Conditioning Research, 23: (supplement 5) / S60-S79.
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A Genetic Link For ACL Injuries?

One of the more hotly debated questions in soccer is why do female athletes suffer more ACL injuries than males. Researchers have proposed a whole host of possible explanations ranging from muscular strength to hormonal changes. For the first time, a preliminary study headed by researchers at the University of Cape Town, South Africa, has found a possible genetic link. It seems that a gene variant in one of the many genes that responsible for the production of collagen (the primary component of ligaments and tendons) may affect the risk of suffering an ACL injury.

A gene variant is a small variation in the genetic code. In many cases, gene variants affect health and may increase the risk of developing various diseases. The COL5A1 gene is responsible for the production of type V collagen. Collagen is the major protein found in ligaments and tendons. It gives these tissues, strength and elasticity. Compared to type I collagen, Type V collagen is a relatively minor component. However, it is necessary for organizing and strengthening Type I fibers. In an earlier study, this research group found the absence of what is called the CC genotype of COL5A1 BstUI RFLP to associated with increased risk of chronic tendinopathy (pain and swelling of the Achilles tendon). Based on this, they set out to determine if this same genetic variant was associated with increased risk of ACL injuries.

The investigators examined a total of 345 athletes from various sports. Of these 38 women and 91 men had suffered an ACL tear. Care was taken to match the injured and non-injured athletes in terms of age, weight, height as well as participation in contact, non-contact, non-jumping and skiing sports. A blood sample was taken and analyzed for variants in the COL5A1 gene.

Two key findings emerged from the results. First, women who possessed the CC gene variant were less likely to have suffered an ACL injury. Second, women who had a sibling with an ACL rupture were twice as likely to have had their own ACL torn. Interestingly, the risk of ACL injury in men was not affected by their gene variant.

This study if the first to suggest that there is a genetic component for ACL injury in women. Possessing a variant in one of the genes responsible for Type V collagen production seems to affect the female athlete’s risk of suffering an ACL rupture. Athletes who have the CC variant have reduced risk while those with other variants seem to have increased risk of injury.

What does this study mean for female athletes? First, this is a relatively small and preliminary study. More confirmation is needed to verify the results. Second the degree of risk associated with this gene variant is not clear. There are several examples of preliminary studies that initially showed a link between various factors and ACL injury risk. Subsequent studies failed to confirm the initial results or indicated that the risks were very small. So, further research is needed before we draw firm conclusions.

Third, let’s assume that the results are true and that this gene variant greatly affects risk of ACL injury. Then the importance of the study lies in the possibility of identifying “at risk” athletes before an injury occurs. A blood test could tell athletes, physicians and trainers which athletes are more likely to suffer a ligament tear. This information could then be to provide preventative measures to reduce the risk of injury. Those athletes without the CC variant of the COL5A1 gene might be given targeted training programs, special diets or preventative bracing / taping.

For the first time, researchers have identified a genetic risk factor for ACL ruptures in female athletes. While more research is needed to confirm these preliminary results, it may soon be possible to identify “at risk” individuals and design programs to counter this risk.

Reference:

Posthumus M, September AV, O’Cuinneagain D, van der Merwe W, Schwellnus MP, Collins M (2009) The COL5A1 gene is associated with increased risk of anterior cruciate ligament ruptures in female participants. American Journal of Sports Medicine, DOI: 10.1177/0363546509338266
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Substitutes: Combating Fatigue or a Strategic Change?

On February 10, 2008, during a scoreless draw with Siena, AC Milan coach Carlo Ancelotti, subbed in Alberto Paloschi. Fifteen seconds later, on his first touch of the match, Paloschi scored the only goal of the match. Many times matches hinge of the strategic use of substitute players. Coaches typically make substitutions late in the match for two key reasons. The first is a tactical move, as with Paloschi, an effort to increase the chances to earn a goal or to hold onto a lead. The second is to replace a player who is showing signs of fatigue, one whose work rate has declined. A recent study looked at this latter reason. Do coaches substitute players for lack of effort and do these substitutes pay off with higher level of intensity?

Researchers examined teams from the French First Division professional league. They tracked individual player movements using a multiple-camera tracking system. Over the course of the season, they followed the movements of both starters and second-half substitutes. The work rates of substitutes were compared to those of players remaining on the field and to the work rates of the players that were replaced. The researchers quantified “work rate” based on the distance ran, the number of high intensity efforts (e.g. sprints) and the recovery time between sprints.

By measuring player work rate, the investigators came away with three key findings. First, there was no drop off in the work rate of players who were replaced. The players who were subbed out showed the same work rate in both the first and second periods with no signs of fatigue. This suggests that most of the substitutions were made for strategic reasons rather than to remove a player who was fatigued.

Second, the work rate of forward substitutes was no greater than the work rate of the players that they replaced. In fact, the replacements had a slightly lower work rate during their first 10 minutes of play. The researchers mention that this may be due to the substitutes not being able to “get into the game”. It is also possible that match conditions, such as trying to protect a lead, may limit a substitute forwards involvement.

Third, the midfield substitutes work rate was noticeably greater than that of the players that were replaced. They tended to cover more distance and a higher intensity and spend less time recovering between sprints. It seems that midfield replacements get involved in the match more quickly that forwards.

This preliminary study provides some insight into why substitutions are made and if this strategy can potentially affect the match. However, as with many research projects, it also raises a number of important questions. First, do work rates of substitutes vary based on the status of the match? Will a replacement forward work at a high rate if his/her team is trailing? Second, when protecting a lead, teams often replace a forward with a midfielder. Does this affect the work rate of either the substitutes or players remaining on the field? Lastly, these results suggest that forward replacements do not utilize their full physical potential compared to midfielders. Perhaps this information can be used to emphasize the need for forward substitutes to elevate their intensity during the initial minutes after they enter the match.

Reference:

Carling C, Espie V, LaGall F, Bloomfield J, Jullien H (2009) Work-rate of substitutes in elite soccer: A preliminary study. Journal of Science and Medicine in Sport, doi:10.1016/j.jsams.2009.02.012
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Cutting Edge Research: Age Effect At The U17 World Cup

Is there an advantage to being born in the early part of the year? The relative age effect means that if you are born close to the cut-off age for a competition; you are more likely to be selected for the team than if you are born later in the year. This phenomenon seems to occur at all levels of play from local travel teams to the most advanced youth competitions. A new study published in the Scandinavian Journal of Medicine and Science in Sports shows that in nearly all countries participating in the U17 World Cup, there is a strong relative age effect. In fact, nearly 40% of the players are born in the first three months of the year while only 16% are born in the last quarter.

In this study, the rosters of all teams participating in the last six U17 World Cup competitions were obtained from FIFA. The player birthdates were recorded and analyzed to determine of there was a trend for players to be born in one part of the year versus another.

The first figure shows the percent of players born each month. It’s easy to see that there are far more players born in the early part of the year than in the later. This trend holds for all six competitions, and for all of the FIFA regions except Africa (more on this later). Also, the most and least successful teams showed similarly strong age-effects.

Several previous studies into the relative age-effect show that in many youth sports, it is advantageous to be born near the cut-off date for a give competition. For international soccer competitions (e.g. U17 World Cup), that cut-off date is based on the calendar year. For American youth soccer, that date is associated with the American school year, July 31.

Studies show that the relative age-effect most often occurs because coaches who select players for advanced training or competition typically use physical and psychological maturity as a major indicator of performance. Thus, those players with early birthdates tend to be bigger and faster than those born later in the year. As discussed previously on the Science of Soccer Online, this may have dramatic consequences for player development (click here). Potential players with late birthdates are being overlooked at a young age simply because they are not as physically mature. They are then denied the developmental opportunities that their older counterparts are offered. As a result, the talent pool for national teams, especially at the U17 level, may be diminished.

Back to the African countries... The African region showed a much different patters of birth month distribution that the other regions. For the African teams, in particular, the western African countries of Ghana, Nigeria and Togo, showed a reverse age effect. That is, more players were born in the later part of the year than in the early months. 14% of the African players were born in December. Also of all underage players participating in the tournament, 41% were on African team rosters. The second figure clearly shows the spike in African birth dates in December of the competition year. Contrary to other regions, in Africa, it seems to be more advantageous of be born in the late in the year rather than early.

It’s not clear why the African teams show this trend. One explanation is that the African teams manipulate birth certificates in order to make older players eligible for competition. It is also possible that there are legitimate errors on African players’ birth certificates. According to UNICEF, many African births are not registered. That is, many African children are not issued a birth certificate when born. For many kids, birth certificates are issued years after birth. In these cases, parents often guess the actual birthdates. So, it’s not surprising that some player’s birthdates might be clustered in a single month.

The bottom line, even at the highest level of youth competition, the FIFA U17 World Cup, the relative age effect exists. Whether this is the result of long-term trends in the player selection process or the training environment provided for older players is not known. In either case, there are several negative outcomes for excluding potentially exceptional players based on their relative age and maturity.

Reference:

Williams JH (2009) Relative age effect in youth soccer: analysis of the FIFA U17 World Cup Competition. Scandinavian Journal of Medicine & Science in Sports. In press, DOI:10.1111/j.1600-0838.2009.00961.x
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Getting a Bigger Bang for Your Training Buck?

Coaches and athletes are constantly searching for ways to improve fitness. Endurance and interval training are the most often used. However, these programs usually require a time commitment of 30-00 minutes per day. This time commitment makes it difficult, if not impossible, to incorporate endurance training into a typical practice session. Researchers at McMaster University have found that a program brief, high intensity exercise might actually improve fitness more than a traditional endurance training program. This program requires only 2-3 minutes of exercise per session – a much bigger bang for the training buck. But, can this type of training be effectively used by soccer players?

In a series of studies headed by Dr. Kirsten Burgomaster, the researchers asked their subjects to perform a very small number of very high-intensity bouts of exercise. The high-intensity training groups used a stationary bicycle and performed 30 seconds of all-out, supra-maximal exercise - they pedaled as hard as they could for 30 seconds. They then rested for 4 minutes and repeated the bout 4 to 6 times. This was done 3 times per week for either 2 or 6 weeks. For comparison, an endurance training group cycled continuously for 40-60min per session, 5 times per week.

After only two weeks of training (only 6 sessions), the high-intensity group, doubled endurance time. That is, they exercise for nearly twice as long before reaching exhaustion. They also improved time-trial performance by 10%. The endurance group showed little to no improvement. After 6 weeks the high-intensity group showed several important biochemical changes within the muscle, such as glycogen, phosphocreatine levels and metabolic enzyme activities. Interestingly, laboratory measures of “fitness” such as VO2max and exercise heart rates were not improved.

A key difference in the two training groups was the amount of time spent training and the total amount of work performed. Training for high-intensity group required about 2-3 minutes of actual exercise compared to 60 minute for the endurance group. Including recovery, the high-intensity session lasted ~20 minutes. Also, the high-intensity group performed about half as much total work as the endurance group. The bottom line is that high-intensity training resulted in greater improvements with less time and work.

As a coach, it’s easy to see how this type of high-intensity training would be a tremendous benefit for improving fitness when practice time is limited. The big question is, should coaches consider using this type of training with their players? Instead of using an exercise bike, players could do repeated 30 second sprints (or 200-300 meter sprints) with a 4 minute recovery. However, there are a few things to consider before abandoning traditional training. First, the researchers are quick to point out that they don’t know for sure if high-intensity training provides all of the cardiovascular, metabolic and muscular benefits that traditional endurance training does. It’s also not known if the improvements are long lasting. Second, it’s not known if the improvements found in these studies will translate into improved fitness over the course of a 70-90 minute match. This is particularly important when one considers the stop-start, run-sprint nature of soccer. Third, and most importantly, cycling is much different than running when it comes to impact forces on the knee, ankle and hip. Using high-intensity running during training might increase the risk of orthopedic, over-use injuries, especially in young athletes. At the very least, players should be allowed a day or two to recover from each training session.

For now, this series of studies raises some very interesting ideas regarding training. They may ultimately cause us to re-think how we go about fitness development. However, much more work needs to be done to determine of high-intensity training is appropriate and effective for young footballers.

Note: Many thanks to Dr. Don Kirkendall of the FIFA Medical Assessment and Research Centre for suggesting this topic.

References:

Gibala MJ, McGee SL (2008) Metabolic adaptations to short-term high-intensity interval training: A little pain for a lot of gain? Exercise and Sports Sciences Reviews, 36:58-63.

Burgomaster KA, Howarth KR, Phillips SM, Rakobowchuk, MacDonald MJ, McGee SL, Gibala MJ (2008) Similar metabolic adaptation during exercise after low volume sprint interval and traditional endurance training in humans. Journal of Physiology, 586:151-160.

Gibala MJ, Little JP, van Essen M, Wilkin GP, Burgomaster KA, Safdar A, Raha S, Tarnopolsky MA (2006) Short-term spring interval versus traditional endurance training: similar initial adaptations in human skeletal muscle and exercise performance. Journal of Physiology, 575:901-911.

Burgomaster KA, Heigenhauser GJF, Gibala MJ (2005) Effect of short-term sprint interval traiig on human skeletal muscle carbohydrate metabolism during exercise and time-trial performance. Journal of Applied Physiology, 100:2041-2047.

Burgomaster KS, Hughes SC, Heigenhauser GJF, Bradwell SN, Gibalb MJ (2004) Six sessions of sprint interval training increases muscle oxidative potential and cycle endurance capacity in humans. Journal of Applied Physiology, 98:1985-1990.



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No Place for Alcohol

One of the time-honored, post-match traditions of adult league soccer leagues is to head to the pub and have a pint or two (or three). Many believe that beer and other alcohol-containing drinks actually aid recovery. The argument is that alcohol is a carbohydrate and carbohydrates help replenish energy stores. In fact, some athletes jokingly refer drinking beer as “carbohydrate loading”. Unfortunately, research clearly shows that drinking alcohol after exercise does not aid in recovery. In fact, beer and other adult beverage can dramatically impair the recovery process by affecting muscle damage, energy replenishment and re-hydration.

A new study published in the Journal of Science and Medicine in Sports emphasizes this point. The researchers examined the effect of post-exercise alcohol consumption on markers of muscle damage and soreness. They asked their subjects perform a strenuous bout of exercise which was followed by a meal. One group drank orange juice (control) while the alcohol group drank orange juice mixed with vodka. For this group the total amount of alcohol consumed was equal to 8-9 standard drinks.

At 36 and 60 hours after exercise, muscle force produced by the alcohol group was considerably lower than the control group, 15-20% lower. Those in the alcohol group also reported higher ratings of muscle soreness and the 36 and 60 hour measures. Diminished muscle performance and increased pain, clearly two strikes against alcohol.

The investigators explained that the alcohol consumption after exercise likely magnifies the amount of muscle damage that is typically associated with strenuous activity. The type of muscle damage that leads to muscle soreness typically occurs in several stages (see The Painful Truth About Muscle Soreness). The first occurs during exercise. The second occurs immediately after exercise and the process usually last for several hours. This is the process that seems to be increased by alcohol , possibly through its negative effects on the immune system and inflammation. Whatever the cause, it’s clear from this study that the effects of drinking after exercise can literally be felt for several days.

The conclusion that alcohol is not a good recovery drink is supported by several earlier studies. These studies show that consuming alcohol after exercise adversely affects energy replenishment. Drinking after a match can impair the metabolism of carbohydrates which leads to reduced blood glucose levels and diminished replacement of muscle glycogen. In addition, consuming alcohol-containing drinks typically reduces the intake of other carbohydrates that are essential to recovery. As discussed previously on the Science of Soccer Online (link), restoration of muscle glycogen is possibly one of the most important aspects of recovery. Thus, from metabolic point of view, drinking after a hard match can prevent the muscles from replenishing much needed energy stores. Despite it being a carbohydrate, it actually hinders recovery.

Alcohol is also a potent diuretic that causes fluid loss through urination. It makes sense that drinking after a match can lead to further dehydration. Much of the fluid that is being consumed through alcoholic beverages is also being excreted. Research has shown that anything containing 4% or more alcohol can lead to further dehydration after exercise. By way of comparison, anything other than light beer contains more than 4% alcohol.

So, despite the popular belief that beer and other adult beverages help recovery from exercise, the scientific evidence clearly shows otherwise. Alcohol consumption after strenuous exercise 1) intensifies delayed-onset muscle soreness, 2) impairs muscle glycogen replenishment and 3) hinders re-hydration. So, hoisting a few pints after a hard match can leave the player in poor condition of play the following day. The bottom line... there is no place for alcohol after exercise.

References:

Barnes MJ, Mundel T, Stannard SR (2009) Acute alcohol consumption aggravates the decline in muscle performance following strenuous eccentric exercise. Journal of Science and Medicine in Sports, in press (doi:10.1016/j.jsams.2008.12.627)

Burke LM, Collier GR, Broad EM, Davis PG, Martin DT, Sanigorski AJ, Hargreaves M (2003) Effect of alcohol intake on muscle glycogen storage after prolonged exercise. Journal of Applied Physiology, 95:983-990.

Heikkonen E, Yilkahri R, Roine R, Valmaki M, Harkonen M, Salaspuro M (1998) Effect of alcohol on exercise-induced changes in serum glucose and serum fatty acids. Alcohol Clinical and Experimental Research, 22:437-443.

Shirreffs SM, Maughan RJ (1997) Restoration of fluid balance after exercise-induced dehydration: effects of alcohol consumption. Journal of Applied Physiology, 83:1152-1158.

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Cutting Edge Research: A New Way to Drink Sports Drinks

For years, sports drink companies such as Gatorade® and Powerade® have extolled the benefits of their products. They argue that sports drinks can replenish energy, electrolytes and fluid lost during exercise. The scientific community has largely shown that this is in fact the case. Sports drinks can play a key role in the recovery from prolonged exercise. However, there may be an added benefit of sports drinks and athletes might consider a new way to drink them. A new study shows that these beverages may also have short-term effects on the central nervous system – but only if they are consumed correctly.
A group of researchers from Ghent University in Belgium examined whether or not simply rinsing the mouth with a sports drink affects endurance performance. Twelve trained cyclists participated in four exercise trials. For each trial they were asked to complete a certain amount of work in as short of time as possible. The trials were designed to last about 60min.

Before and during each trial, the athletes were given either a sports drink (Gatorade) or an artificially sweetened placebo. For two of the trials, they took in ~120ml (~4 ounces) of the beverage, rinse it in their mouth for 5 second then spit it out. For the other two trials, they drank an equal volume of Gatorade or placebo.

The time needed to complete the ride was significantly lower when the Gatorade was used as a rinse compared to when the drink was actually consumed. Under the sports drink rinse condition the cyclists completed the ride in 61:42 compared to a mean time of 63:16, an improvement of almost 4%. This occurred despite slightly lower blood glucose level and blood lactic acid concentration. It appears that simply rinsing the mouth with a sports drink for ~5 second causes a diminished perception of effort for a given exercise intensity. That is, the riders could exercise harder for the same degree of discomfort.

The researchers point out that actually drinking the Gatorade did not affect endurance performance while rinsing the mouth did. This is intriguing since most experts would have expected the opposite to be true. It also means that something must be happening in the mouth rather than that through digestion. It is possible that the carbohydrates in the sports drink interact with some sort of “receptors” in the mouth to stimulate the central nervous system. This effect might, in turn, improve the athlete’s effort and aid performance. While this is speculation on behalf of the researchers, there is some logic in their idea.

As for soccer players drinking sports drinks, it probably not advisable to rinse and spit as was done in this study. Ingesting both carbohydrates and fluids are critically important during recovery and for avoiding dehydration. However, athletes should consider that gulping their Gatorade may not be the best approach. The might try taking a drink, holding it in the mouth for 5 second before swallowing. This might maximize the short-term effects on the central nervous system as well as benefit from the long-term effects on energy storage and hydration. In the end, holding your drink in your mouth for a few seconds before swallowing might provide a small edge during the match.

References:

Pottier A, Bouckaert J, Gillis W, Roels T, Derave W (2008) Mouth rinse but not ingestion of a carbohydrate solution improves 1-h cycle time trial performance. Scandinavian Journal of Medicine and Science in Sports, DOI: 10.1111/j.1600-0838.2008.00868.x

Carter JM, Jeukendrup AE, Jones DA (2004) The effect of carbohydrate mouth rinse on 1-h cycle time trial performance, Medicine and Science in Sports and Exercise, 36:2107-2111.
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