Soccer articals

hydration in football

Hydration football - It used to be oranges in the centre circle... now it's a personal hydration strategy

One of the key areas where nutrition can have a direct impact on performance is in the area of hydration. There is good evidence that players who become dehydrated are more susceptible to the negative effects of fatigue, including loss of performance and increased risk of injury. There is also growing evidence that excessive sweat losses, especially high salt losses, can be a factor in some of the muscle cramps that affect players in training and competition.

Recently, however, a number of clubs have recognised that hydration is important and that no single strategy suits all players in all environments. This has led to an assessment of individual needs so that a personal drinking strategy can be put in place. This practice appears to have gained ground in American football, where pre-season training typically takes place in extreme heat and involves two sessions per day. In recent years, a number of high-profile fatalities, including that of Korey Stringer in the NFL, have raised the awareness of what can happen when things go seriously wrong. Several of the top English football clubs now have monitoring strategies in place.

Zero-cost analysis

A slightly better measure is obtained if the player is weighed before and after training or competition (nude and dry on both occasions) and his (or her) drinks bottle is also weighed before and after, assuming that all players drink from their own bottles and that anything that is taken from the bottle is swallowed and not spilled/poured over the head/spat out. If the decrease in weight of the drinks bottle is added to the decrease in weight of the player, we get the actual sweat loss. We also get a measure of the player’s drinking behaviour.

All of this is easy to do, and all it requires is a set of kitchen scales to weigh the drinks bottles, a reliable set of scales to weigh the players, and a bit of organisation. The cost is effectively nil – just a bit of time and effort on the part of one of the backroom staff. There is one more measure that can be usefully added, but this needs rather more specialised apparatus and is thus likely to be the preserve of the top clubs only: the measurement of salt losses in sweat.

Identifying salty sweaters

We have made these measurements on the first team squads at a number of Europe’s top teams, typically testing about 20-30 players at each club. They results have been consistent between clubs when the training sessions have been similar, but the variability between individual players has been striking. Key findings in a typical 90-minute training session are as follows:

1. 
   Average sweat loss is typically about 2L, but this can vary from about 1L to over 3L, even though all the players are doing the same training in the same conditions and are wearing the same amount of clothing.
   
2. 
   Average fluid intake is typically about 800-1,000ml, but this can vary from about 250ml to over 2L.
   
3. 
   There is no relationship between the amount of sweat a player loses and the amount he drinks.
   
4. 
   The sweat salt content varies greatly: the better acclimatised players have lower sweat content, but again there is a large individual difference. Sweat salt (sodium chloride) losses can reach almost 10g in a single training session in some players, and this during twice-a-day training. Others lose only small amounts – 2g or less in the same training session.
   
5. 
   When training takes place in the cold, sweat losses may be almost as high as when training in the heat, but players drink far less and so end up just as dehydrated – or even more so.
   

There is also a suspicion – and I should stress it is no more than a suspicion at present – that players with a very high sweat salt content are more prone to cramp and that this risk can be reduced by salt supplements.

These simple steps can make a difference between being able to score that vital goal in the last minute and being a virtual spectator. It is only surprising that it has taken the world of professional football so long to realise this.

Ron Maughan

football managers

Football managers - Who is there to support the managers? A psychologist reflects on survival techniques in a cut-throat world

You only have to read the sports pages or listen to the news to learn of yet another football manager who has got the sack, might get the sack or is in trouble. The world of the professional football manager is one in which danger and uncertainty about the future hover over every match the team plays. It is often a lonely and isolated position, which can leave managers vulnerable to psychological stress.

Here, I review the season I spent working with a professional football manager in my capacity as a sports psychologist. While the manager’s name must remain confidential, I want to make it clear that I have his full permission to write what follows. The journey I embarked upon taught me many important lessons about the culture of football and its impact on the psychological wellbeing of managers. I also learned how a sports psychologist could support a football manager in what is often hostile territory.

Initially, I focused on developing an understanding of the manager’s work environment. I needed to know what demands were being placed upon him and what their impact was. I discovered that football managers are subject to four main sources of pressure that influence their psychological wellbeing:

• 
  the players;
  
• 
  the club owners;
  
• 
  the fans;
  
• 
  the media.
  

The overall effect is to create a climate of uncertainty and insecurity for the manager. The elements of this climate that impact most significantly on his psychological wellbeing are as follows:

• 
  lack of personal security;
  
• 
  isolation;
  
• 
  fear of public humiliation;
  
• 
  lack of control over his own destiny (ie the players ultimately decide his fate);
  
• 
  need to appear strong and in control;
  
• 
  need for quick fixes;
  
• 
  culture of non-sharing;
  
• 
  ego-oriented culture in which everyone is an expert.
  

What became apparent to me during the season was the lack of support available for the manager, who was often working in isolation to solve difficult problems. In theory, the assistant coach and the management were available to work with the manager, but in reality the manager was responsible for every decision. The fact that he then had to justify those decisions to everyone else was an additional source of stress.

Exploration of the manager’s mindset revealed pendulum-like swings from very negative to very positive which were completely dependent on the outcomes of matches. The following quotes illustrate some of the widely-held beliefs within football that were wholeheartedly embraced by the manager I was working with:

• 
  ‘When you don’t win people don’t believe in you’;
  
• 
  ‘When you are winning you are never wrong’;
  
• 
  ‘Players will lose you your job’;
  
• 
  ‘You live and die by your decisions’;
  
• 
  ‘I am too soft’;
  
• 
  ‘Results make you God’.
  

While it has been widely accepted that low self-confidence impacts negatively on an athlete’s performance, its effects on the performance of managers have been generally ignored. Furthermore, the consequences are particularly grave for managers: if the team’s results are poor the owners will still own the club, the players will still play for it and the fans will still support it, but the manager will be sacked in an effort to improve the team’s performance. This knife-edge existence leaves managers very vulnerable.

As my season progressed, it became clear that the toughest issues the manager had to contend with occurred away from the pitch. Examples included players trying to adjust to life in a foreign country, players facing retirement, players involved in gross misconduct, marital difficulties and older players intimidating younger ones. While these issues might appear to have nothing directly to do with the players’ ability to play the game, it became clear that the manager’s ability to help his players resolve them did have a direct impact on performance. And it is in these situations that football expertise, knowledge and ability can’t help you even though they might be the reasons why you were given the job.

It was also clear that these situations impacted in different ways for the team and the manager. Your perception of any situation will vary considerably, depending on your role within an organisation. The diagram (right) illustrates a situation in which there were differing beliefs within the team regarding a decision made by the manager. The consequence of this was a shift in the team dynamics, causing rifts and a negative impact on performance. For the coach, the situation generated inner conflict and uncertainty, which led to a lack of self-belief. The result of this was a change in coach behaviour to a more autocratic style.

My role as a sports psychologist was to work with the manager to help him find solutions. However, in order for my work to be effective there were a number of fundamental principles that defined the working relationship:

• 
  First, the confidentiality of the manager had to be assured. The importance of this principle should not be underestimated, given the culture of football. If other people had known about the work it could have been compromised, as could the manager’s position;
  
• 
  Secondly, it was important that I was not a stakeholder in the club and was there solely for the manager’s benefit;
  
• 
  Finally, it was important that I was non-judgmental about – indeed unconcerned with – the results. Our agenda was focused on the manager’s response to any given situation, whether on or off the pitch.
  

What I learned from my experience was that it is vital to really understand the culture of the game, so that, in a very real sense, you can learn to speak the same language as those who inhabit the football world. Coming from an essentially non-football background, I had to work hard to appreciate the context within which the manager’s job was being undertaken. Sometimes I got it wrong, but through questioning and acknowledging my own limitations I developed my understanding. Ultimately this made me more effective in my role. I discovered that it was good to challenge current practice, but that we had to work through realistic alternatives that would work in football. My role was to support the manager, not solve player problems.

My work with the manager had three key aims:

• 
  To develop more effective inter-personal communication skills;
  
• 
  To enhance understanding of group dynamics, and how to affect them;
  
• 
  Personal stress reduction.
  

In summary it is clear to me is that the managers of the future need to develop skills in inter-personal communication and to have an understanding of group dynamics and effective group management. They also need to work to develop personal coping and stress-reduction mechanisms if they are to survive the cut-throat world of football management.

Given the enormous importance of football referees – reflected in the almost universal tendency for die-hard fans to displace frustrations with the team onto their hapless shoulders – it is surprising that sports scientists have paid so little attention to their physical and psychological status and performance.

Now a pair of Brazilian researchers have attempted to redress the balance somewhat with a study of hydration status in six male refs and six assistants (linesmen) during matches of the 2000 Paraná football championship, held in Brazil in their autumn months of March, April and May.

Why study hydration status, you might ask? The answer is that negative effects on performance have been shown with modest degrees of dehydration (2% of body weight). And it is generally accepted that cognitive performance is also impaired when dehydration and hyperthermia are present, which could be particularly relevant to the decision-making aspects of refereeing.

The subjects were weighed without clothes and had blood samples taken before and after each match, after emptying their bladders. The difference in readings before and after a match, plus ad lib water intake at half-time and urinary volume, were used to estimate total body water loss during the match, with the assumption that a body mass loss of 1kg was equivalent to loss of 1 litre of fluid. The blood tests were analysed for changes in plasma volume – the fluid portion of the blood.

The key results were as follows:

• 
  Referees lost 1.22kg of body weight during matches, equivalent to 1.55% of their pre-match weight. Total body water loss averaged 1.60L, equivalent to 2.05% of their pre-match body weight. The difference between the two measurements reflects their half-time fluid intake;
  
• 
  Linesmen, by contrast, lost only 0.48kg (0.63%) of their body weight and body water loss averaged 0.79L, equivalent to 1.05% of their pre-match body weight;
  
• 
  The referees showed a reduction in their plasma volume, while the linesmen showed no significant changes in haematological status.
  

‘The physical activity performed by referees is a combination of various types of exercise (walking, jogging, sprinting and reverse running) covering an average distance of 9.3 miles in a match,’ they point out. ‘Our results show that this amount of activity caused significant dehydration which was not redressed by the spontaneous intake of water during the interval.

‘Additional studies are required to find the best form of fluid replacement for football referees (during, before and after a match) to prevent a decrease in their physical and mental performance.’

Br J Sports Med 2003;37:502-506

soccer fitness training

Soccer fitness training: Endurance training boosts performance in the field

Soccer players need a combination of technical, tactical and physical skills in order to succeed. It is odd, therefore, that Soccer research has tended to focus on technique and tactics, with little emphasis on how to develop the endurance and speed needed to become a better player.

Some studies have also shown that Soccerers tend to cover less distance and work at lower intensities during the second half of games than during the first half. The logical interpretation of these findings is that fatigue is limiting the players and that if they were fitter they would perform more effectively in the latter stages of their matches. None the less, until now no investigation has clearly shown that improving aerobic capacity and overall fitness boosts performance on the Soccer field.

Fortunately, that deficiency has now been remedied, thanks to the work of Jan Helgerud and his colleagues at the Norwegian University of Science and Technology in Trondheim(3). Their new study involved 19 male players from two Norwegian junior lite teams - 'Nardo' and 'Strindheim' - all of whom had been playing Soccer for at least eight years. Both teams had been among the most successful in Norway over the past five years and six of the participants were members of the Norwegian national junior team. The players had an average age of 18 and mean mass of 72kg (158lb).

Aerobic interval training v extra technical training

At the beginning and end of the eight-week study period, all players were tested for VO2max, lactate threshold, vertical jumping height, 40m sprint ability, maximal kicking velocity and the technical ability to kick a Soccer through defined targets.

After eight weeks of twice-weekly interval training, the players in the training group had improved VO2max by almost 11%, from 58.1 to 64.3 ml.kg-1.min-1; meanwhile control group players had not upgraded VO2max at all! Similarly, lactate-threshold running speed improved by 21% and running economy by 6.7% in the training group, while controls again failed to improve at all. Clearly the players in the training group were gaining tremendous physiological benefits from just two aerobic workouts per week!

Happily, all of these physiological details translated into some markedly improved performances on the Soccer field: interval-trained athletes increased the total distance covered during games by 20% (from 8,619 to 10,335m) and also doubled the number of times they sprinted during games (a sprint being defined as an all-out run lasting at least two seconds). Furthermore, after eight weeks of interval training the number of involvements with the ball per game increased by 24%, from 47 to 59. (Involvements were defined as situations in which a player was either in physical contact with the ball or applying direct pressure to an opponent in possession of the ball.)

Interval training also boosted the athletes' overall ability to play at high intensity; after eight weeks of interval work, they were able to perform at an average of 85.6% of max heart rate during their games, compared with just 82.7% beforehand. Training group members also spent 19 minutes longer than controls in the high-intensity zone (ie above 90% of max heart rate) during an actual game.

Of course, interval training isn't a panacea, and sprint speed, squatting strength, bench-press strength, jumping height, kicking velocity and the technical shooting and passing test were unchanged by the aerobic work, as you might expect.

None the less, this very simple interval training programme (with just two workouts per week and four 4-minute intervals @ 90-95% of max heart-rate per workout) produced some dramatic improvements in overall play. Put simply, boosting VO2max, lactate threshold and running economy with interval routines gave the players an enhanced ability to cover longer running distances at higher intensities during games and to be involved with the ball more frequently and thus play a greater role in deciding the outcomes of competitions.

No Soccerer can argue that he/she does not have enough time for such additional training, which should be included in all overall programmes. Interestingly enough, the VO2max ultimately attained by the interval-trained players (64.3 ml.kg-1.min-1) is above the average VO2max reported for experienced international Soccerers, suggesting that a large number of Soccer players could benefit from aerobic training.

Athletes in many other disciplines which are not traditionally viewed as endurance sports might also benefit from the kind of interval training carried out by the Norwegian Soccer players. In particular, interval work should offer advantages for those involved in rugby and basketball.

Recent research carried out at the Victoria University of Technology in Australia revealed that basketball places huge demands on the cardiovascular system, suggesting that aerobic capacity improvements might upgrade the quality of play(4). In this study, eight players (three guards and five forwards or centres) from the Australian National Basketball League were monitored during league competition and practice games. Each competition consisted of four 12-minute quarters, with a 15-minute break at half time and two-minute breaks between quarters. Maximal aerobic capacity (VO2max) was determined for each player.

When the ball was in play, there was a change in movement category (for example, from medium-intensity shuffling to sprinting) every two seconds, and 'very intense' activity accounted for almost 30% of court time. This translated into a heavy load on the players' cardiovascular systems, with heart rate during play averaging 89% (compared with 86% of max for the interval-trained Norwegian Soccer players and 83% for the Norwegian controls). Basketball players' heart rates were above 85% of max for at least 75% of court time. Even more impressively, cardiac beating was in the 95-100% of max range for 15% of court time and in the 90-95% range for 35% of total time. During free-throw shooting, heart rates recovered to around 70-75% of max.

Interestingly, blood-lactate levels were also quite high in the basketball players, with average lactate concentration at 6.8 millimolars (mM)/litre. Somewhat surprisingly, lactate levels as high as 13 mM/litre were recorded in some of the athletes, comparable to those seen in top-level sprinters after 400m races. These findings suggest that lactate-threshold improvement might benefit basketball players' performances.

As it turned out, the Australian basketball players had average VO2max readings of 61 ml.kg-1.min-1, compared with 64.3 in the interval-trained Soccer players and 59.5 in the control group. This suggests not only that basketball itself boosts VO2max but also that improvements in VO2max might foster better play, just as it does in Soccer.

What other interval workouts besides the Norwegians' 4x4-minute scheme might be beneficial for Soccer and basketball enthusiasts? Clearly, some of the renowned French scientist Veronique Billat's 'v VO2max' sessions would be helpful, since they are very intense in nature and lead to enhancements in VO2max, lactate threshold, and running economy.

Two of Veronique's workouts should be particularly beneficial:

l The 30-30. To perform this workout, athletes should simply warm up effectively, then alternate 30 seconds of running at close to max intensity with 30 seconds of easy ambling. Initially, they should go for 10 reps, but as aerobic capacity improves they can simply keep going until fatigue kicks in;

l The 3-3. This is like 30-30, except that athletes alternate three minutes of hard running with three minutes of loping. The pace for the strenuous three-minute intervals should be determined by the best-possible speed achieved during a six-minute test. (Naturally, 're-tests' of six-minute velocity will be needed every 4-6 weeks-or-so, since running capacity should improve.) Few athletes should try to complete more than five three-minute intervals per workout.

What's the bottom line? In several key ways, Soccer and basketball count as 'endurance sports', since they place a high demand on the cardiovascular system, and since performance ability appears to hinge on physiological variables such as VO2max, lactate threshold and running economy. Thus, performing the types of interval workouts used by endurance athletes should be helpful to players of both sports.

Owen Anderson

References

Science and Soccer, T Reilly, A Lees, K Davids, and WJ Murphy (Eds). London: E & F N Spon, 1988, pp 95-107

2. Proceedings of the 1st International Congress on Sports Medicine Applied to Soccer, Rome, 1980, L Vecchiet (Ed) Rome: D Guanillo, 1980, pp 795-801

training for football and rugby

Football and rugby teams pre-season training

The Third World Congress of Science and Football took place in Cardiff earlier this year. The congress included not only keynote lectures from authorities throughout the world but also short communications and poster presentations on scientific aspects of sport relating to all codes of football. But football wasn't the only sport on the menu--rugby, Aussie Rules, Grid Iron, Gaelic and the fast-growing sport of touch rugby for women Down Under were all discussed as well.

As far as football was concerned, the range of debate was wide, including such areas as psychological and physical preparation of players, coaching, biomechanics, sports medicine, match analysis and sociological perspectives. It was very much a multi-disciplinary conference, so it's a pity there was so little representation from British football clubs, who might have learned something. This could be one reason why British football is starting to lag behind the rest of the world. Other nations appear far more ready to take on new ideas for the preparation of their players.

At this time of year, most clubs are concerned with the conditioning of players in the pre-season build-up. In this period players can concentrate on the development of skills and fitness without the stress of impending competition week in and week out. A couple of papers at the congress addressed the subject of pre- season conditioning, as there is little published work on what is the best blend of training to get to the season in good shape, as well as what fitness improvements can realistically be expected in this training period.

It was surprising to see that in this conditioning period there was only a small improvement in the aerobic endurance of the backs, and little change in that of the forward players. The fitness levels were typical of those expected in good-standard rugby players. There was, however, improvement in flexibility and the strength performance of the players, while there was a decrease in explosive leg power, a vital aspect of performance in the game. It would appear from the data presented that forwards may need to put more effort into improving aerobic endurance than they currently do. Although rugby is characterised by short, intense bursts of activity, there is little doubt that better aerobic endurance would help the players to maintain a higher work output throughout the duration of a match. It is also important to improve explosive power during this conditioning period.

Once again, a battery of fitness tests was used to assess the players both before and after the conditioning period. Over this period there was a significant improvement in aerobic endurance, as shown by a large increase in performing a progressive shuttle run to exhaustion. This improvement in endurance performance, a function of the hard aerobic training undertaken, was also reflected by a significant decrease in body fat percentage. Although performance of an agility run test also improved during the conditioning period, there was no improvement in the other fitness parameters measured, such as anaerobic endurance, flexibility, strength and power. Once again, these are important parts of match fitness which appear to have been relatively neglected in the training programme and may need attention in future.

One difficulty for the coach is in deciding which type of strength training to perform within the overall programme. Thus a comparison between three types of regime was used to help identify the more suitable method. The options were: using a constant resistance, where the load remains the same but the speed of movement can vary as does the muscle length (such as a squat exercise); variable resistance, which was similar, except the load was varied; and isokinetic work. The last needs specialised equipment, where the speed of movement is maintained constant throughout the whole range of movement, which means that the load also varies.

Measurement of the performance of I Repetition Max and isokinetic performance, both before and after the training programme, revealed that the variable resistance condition was most effective in the short term. For rehabilitation, however, the isokinetic condition proved to be most effective as a means of reconditioning the players in a safe and efficient manner.
Taking in carbo and fluids
Once the season gets underway, the emphasis of the coach tends to shift from long-term conditioning of the players to the maintenance of performance during matches. Clearly, fitness has an enormous impact here, but the importance of nutrition should not be forgotten.

A study from Chichester Institute of Higher Education examined the effects of administering carbohydrate before and during the game as a supplement. Because of the high intensity of football for a duration of 90 minutes, it is possible that maintaining carbohydrate levels throughout a match may help performance in the later stages of the game.

A simulated football match on a treadmill was set up, whereby subjects had to perform 30 six-second maximal sprints within a three-minute cycle of walking, jogging and running in an attempt to replicate the demands of the game. The players performed this test twice, once with a carbohydrate drink before the 'game' and at half time, and once with a placebo drink. The results showed that although the blood glucose level was higher after the carbohydrate drink, there was no significant difference in the performance variables such as maximal speeds in the match, or average sprint speed throughout the match.

A similar study was also completed at the same centre, using the simulated match idea, this time examining the ingestion of fluid--in this case, water-- throughout the match. In the previous study, the same amount of fluid was consumed in both conditions; it was just the carbohydrate concentration that varied. Here, the subjects performed two trials again, one with 8ml of water per kilogram of body mass (ml/kg/min) before the test and at half time, as well as smaller doses (2ml/kg/min) every 15 minutes throughout the simulated match. The second trial had no water ingestion at all in the test period.

Players who think they need to worry about drinking only during the warmer summer months should think again. Data collected from an English Premier League Team by Leeds Metropolitan University also examined the effects of dehydration on performance, but this time in actual matches. By carefully measuring the amount of fluid consumed by players and body mass before and after the matches, it was possible to calculate the amount of sweat loss during the matches. The average amount of weight loss during matches was 1.26kg which corresponds to a 1.54 per cent drop in body mass. However, when one considers the amount of fluid consumed in the same period, the actual loss is above 2 per cent. Given that these matches occurred during the winter, the importance of fluid replacement before and during matches is highlighted. It is particularly essential in the first few games of the season, when the temperature and sweat loss are likely to be higher.

(Abstracts of these and many other studies will soon be published in the Journal of Sports Sciences, while full papers of the conference will be published in a book, Science and Football III (E. & F.N. Spon.)
Joe Dunbar