Optimising skill and technique and the concept of adaptation

Adaptation takes place after repetitive exposure to a specific task. The greater the amount of adaptation, the better the athlete’s performance will be. The time required for adaptation will depend on the volume and intensity of the stimulus as well as the complex-ity of the sport. Each sport has its own unique needs and it is for this reason that athletes and coaches need to follow a multilateral approach when establishing a sport-specific plan.

Studies have looked at how different nutrition strategies may trigger training adaptations through nutrient–gene interactions (nutrigenomics) involved with training. An example of a strategy would be the ‘train-low, compete-high’ regimen which has become popular even in some team sports and is based on the premise that by training with low mus-cle glycogen stores (achieved by a low-carbohydrate diet, training or manipulating timing of training) subsequent training adaptations will be improved.

However, more conclusive results from longer-term studies conducted on trained athletes ‘in the field’ are

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needed before global practical recommendations can be made. Should athletes wish to experiment with this approach, it would be prudent to do this early in the season/pre-season.

Training for the technical aspects of sport involves many hours of focused mastery of specific tasks. The athlete can spend hours perfecting technique and economy of movement. The technical training can begin in more ‘clinical’ or familiar environments and progress into more unfamiliar settings. Training under unusual circumstances can prepare the athlete or team for any eventuality (weather, noise, lighting, pitch condition, equipment, etc.). This will ensure that the athlete can focus on the task at hand rather than the distraction of external stimuli.

Sports such as football and squash require a large amount of anticipation. These sports require the ath-lete to play a mental game of chess while pushing the body to perform at the same time. Training tactical factors allows the athlete and coach to prepare situa-tional probabilities and strategies for each game or each opponent. Sound theoretical knowledge of the sport and the laws of the sport will also enhance performance. The more psychological, theoretical and tactical training that takes place before the com-petition, the less situational stress will be endured during the competition itself.

From a nutritional perspective, it is also vitally important that an athlete, or team, plans for all situa-tions and eventualities. Leaving nothing to chance will go a long way to building overall confidence and reducing unnecessary stress during competition.

Motor learning, cognitive training and skills development

Classroom tactical sessions are commonplace in technical or skilled-based sports. These classroom sessions are essential in the planning process and require exam-like concentration. It is important to recognise that eating plans should be strategised for these sessions as well. Pangs of hunger or low blood sugar levels have the potential to derail the learning process for the athlete.

Training for a technical or skill-based sport is not all about getting the heart rate up, hustle and bustle, or sprinting from here to there. Quieter sessions are also required. Professional athletes will often set aside time for visualisation sessions. This internal form of medi-tation requires a deep peace but also an unrivalled

amount of concentration. For this internal meditation it is important that adequate dietary practices are implemented to ensure that athletes do not lose focus and shift attention onto the next meal they are craving.

It is also important to make sure that the food is the correct food that does not cause bloating or gastroin-testinal discomfort, which may become a distraction.

It is important for athletes to train the way they wish to play. The athlete and coach have to strate-gise the training programme to ensure that physical and mental preparation closely mimics match/

game situations. It is therefore important to chal-lenge the athlete’s cognitive ability under fatigue circumstances likely to be encountered during com-petition situations. However, it is unwise to tamper with the athlete’s diet or sleeping patterns to achieve this fatigue-like state. Strategies like this have been used successfully for elite Special Forces units to condition them for the extreme situations and pos-sible death they may encounter while on duty. The requirements of an athlete and an elite soldier differ remarkably and the coaching team needs to realise this before embarking on a ‘tough-love’ approach.

However, there are other strategies that can be used to challenge the athlete mentally. These strate-gies include ‘pre-fatiguing’ the athlete in a normal training session or match-like session and then using a cognitive drill either related to the sport or a drill aimed at challenging the athlete mentally. The following are examples of some motor learning/

cognitive drills currently in use: situational probabili-ties; anticipation and memory recall; reaction ball (erratic bounce ball); letter ball (ball with random letters/numbers); colour beacons; numbers; direc-tions; agility ladders; electronic resources (Stroop test);

and many more. The only limit to resources such as these is the level of the coaching team’s creativity.

Nutrition strategies

There are several nutrition strategies that may impact on arousal, anxiety, fatigue and skills, but this needs to be considered in conjunction with environmental, psychological and practical factors as in practice this is what may determine food availability, appetite and choices.

Body composition, skill and technique

Body composition may affect skill and technique. In squash, having excessively high body fat levels may

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reduce agility and speed as well as heat tolerance, whilst having excessively low body fat levels may mean an athlete lacks endurance or is not consuming adequate nutrients for training and competition demands. In golf, there is no scientific evidence to show that overweight golfers will improve their game with weight loss; however, there are other benefits such as improved heat tolerance, endurance and fit-ness that may help prevent fatigue and affect skill and concentration.

Practice tips

• Work with the individual athlete to determine appropriate body composition goals and calculate a practical programme that ties in with training (see section on preparation phase, p. 182).

• Monitor all changes, which may need to be gradual as this may also require adjustments to technique.

Carbohydrate

Carbohydrate is recognised as an important ergogenic aid affecting peripheral mechanisms (muscle), and also immune and central nervous function. Inadequate carbohydrate intakes will have a negative impact on performance resulting in fatigue and/or reduced work capacity across a whole range of sports, from single or repeated high-intensity bouts of exercise to sports of moderate intensity but longer duration. The brain is reliant on glucose for its fuel and even subtle reduc-tions in blood glucose concentrareduc-tions or carbohydrate availability to the brain can result in central fatigue.

Thus symptoms related to inadequate carbohydrate intakes range from hypoglycaemia with overt signs of fatigue, to disorientation and impaired work capacity (reductions in pacing strategies or muscle fibre recruitment) to impairments of skill, concentration and tactical decision-making.

Some specific benefits that have been shown to be associated with feeding carbohydrate during exercise (e.g. in football studies) include faster sprint times, higher jump heights (in fourth quarter of team game), reduced force sensation, enhanced and pre-served motor skills (like dribbling ability and shoot-ing), and improved mood late in exercise.

Some recent and intriguing research has shown that even just rinsing the mouth with carbohydrate

(sweet or maltodextrin) during exercise may postpone or attenuate central fatigue development.

The researchers suggest that the caloric content of the carbohydrate activates brain regions that were possibly inactive or inhibited and through this mechanism mediates a neural response. Mouth rinsing may be a useful ergogenic method for ath-letes needing to manage their calorie intake or for athletes who for situational reasons cannot tolerate ingesting large volumes of food/fluid (exercise of greater than 1 hour duration). More research is needed on athletes in competition situations and in a fed state.

Glycaemic index and glycaemic load

It is not entirely clear whether the glycaemic index (GI) (ranking of individual carbohydrates according to overall effects on blood glucose levels) or the glycaemic load (also considers amount of carbohydrate) offers the athlete a clear performance advantage. Some studies have shown that carbohydrate ingestion during endurance exercise negates the effect of the consumption of pre-exercise GI meals while other investigations have shown that when nutritional strategies incorporating GI are applied to multiple meals, there is no clear advantage to the athlete in terms of exercise performance and capacity.

Practice tips

• Carbohydrate intake goals are athlete and sports specific.

Moreover, for an individual athlete, absolute amounts of car-bohydrate required may vary according to specific training and competition schedules (see p. 185 and Table 14.6). Total daily carbohydrate intake goals may be anywhere in the range 3–12 g/kg/day, depending on the type of training, level of competition, and goals of the athlete.

• Timing of carbohydrate proximate to training can impact on performance and recovery: 1–4 g/kg carbohydrate should be consumed 1–4 hours before training/competing; during exer-cise, if the session is 1 hour, mouth rinsing with carbohydrate may suffice, but beyond 90 min of exercise a carbohydrate intake of 0.5–1.0 g/kg/hour is advised and this increases to

∼1.5–1.8 g/kg/min if exercise extends beyond 4 hours.

• Athletes who are especially susceptible to hunger and/or dips in blood sugar, concentration and focus during an event need to ensure an adequate intake of carbohydrate, before, during and after an event, including low GI foods (and foods low in fibre and residue for gut comfort) before the event and then select moderate to high GI foods during and after exercise.

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Protein

The effect of protein on skill and technique is unclear.

Theoretically, the rationale of ingesting branched-chain amino acids (BCAAs) during prolonged exercise would be to improve the psychological perception of fatigue (i.e. central fatigue by decreas-ing serotonin) but studies usdecreas-ing this strategy have shown mixed results. In fact taking BCAAs during exercise may cause ammonia to be produced and this may cause fatigue. There are some studies which report that when inadequate amounts of carbohy-drate are ingested during exercise, and glucose availability is compromised, endurance time to fatigue may be extended by adding protein to sports drinks. However, the mechanism for this is not clear and may just be an energy effect.

Fluid

The impact of hypohydration on performance in team sport and sports involving skill and technique is not as extensive as that seen during endurance exercise.

Interpretation of studies is also complicated by differ-ent protocols, for example the techniques used to achieve hypohydration (sweating, diuretics, exercise, energy restriction) and/or rehydration (volume and type of fluid and rate of ingestion). In team sports, research is complicated by the high degree of inter- and intra-individual variability in work rates between players that are often unpredictable and random.

There is very large inter-individual variation in sweat-ing, and dehydration also affects individuals differ-ently and may be influenced by the type and mode of exercise and temperature outside. Moreover, a cogni-tive skill may deteriorate with dehydration in a labora-tory setting, but psychological arousal in a competition may compensate for the deficit. A lower body mass may make some skills or activities easier, like sprinting or jumping (if muscle force or power is not reduced) and bowling speed in cricket. However, the decrease in physiological demand and subsequent improved per-formance may mask any other potential negative effects of hypohydration (such as bowling accuracy in cricket and withstanding tackles). Current evidence can be summarised as follows.

● Hypohydration, if of a sufficient level, can affect physical and cognitive performance, but not all hypohydration negatively affects performance.

● The environmental conditions experienced by an individual can influence both the hydration status, by means of influencing sweat loss, and the physiological responses to that hydration status.

● Athletes who do not drink anything during exercise will perform less well than they would if they drank ad libitum (according to thirst).

● If players are more than 2.5–3% dehydrated and thirsty in warm to hot conditions, cognitive func-tion, mood and mental readiness may be impaired.

A number of factors come into play when advis-ing individuals or teams on fluid. Other roles that fluid has on performance need to be considered.

Fluid can also be a practical source of nutrients such as carbohydrate (and protein if needed) and electrolytes. By increasing the production of saliva, which has antimicrobial properties, fluid may impact on immune function and help fight infec-tions. Fluid in the recovery period is important, since players continue to lose fluid by sweating or urinating and drinks are a practical way of taking in carbohydrate (and even a little protein), needed for recovery and anabolic processes, when appetite is reduced.

Understanding the individual (e.g. heavier players may require more fluid), the impact of the environment (e.g. in a colder environment, the carbohydrate to fluid ratio of a drink may be higher), the rules of the sport (opportunities to drink), and the influence of uniforms/protective gear is important when developing fluid strategies.

In a sport like Formula 1 racing, the environmental constraints (fireproof outfits and helmet, cabin conditions) and racing conditions impact heavily on fluid demands and delivery. Using practical systems like Camel Packs and specialised in-car drinking systems, and providing fluids with sodium, should be considered. Sodium improves fluid absorption and retention and decreases urine output. Oppor tunities to drink fluid may vary (informal breaks and stoppages in a team sport), the demand for fluid and fuel may vary (e.g. more mobile football players may require more fluid and carbohydrate; a squash player may become dehy-drated at temperatures of 25°C after less than 30 min), and in many sports the length of a game may be unpredictable.

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Practice tips

• Athletes should always take personally labelled drinks to prac-tices, see that they are accessible and familiarise themselves with their own fluid requirements in different environmental conditions.

• Body weight can only be used as a general guideline and to encourage an increased awareness of individual fluid require-ments. Players should be weighed before and after exercise in minimal clothing, taking into account urine losses and drink volume.

• Athletes should start games and training well hydrated and utilise every opportunity (e.g. stoppages/half time) to drink suf-ficient fluid. Players need to continue to replace fluid losses in the recovery period and fluid should also be provided at meal/

snack times to encourage further intake.

• More is not better: athletes should not drink at rates greater than sweat losses so that they gain weight during training or matches.

• Fluid absorption is best if the stomach is kept partially filled during exercise. In a football match for example, this can be achieved by drinking 250–500 ml immediately before running onto the field and then topping this up during the match.

• Sports drinks are practical as they provide carbohydrate and electrolytes such as sodium as well as fluid.

• Having access to cool and flavoured fluids may encourage intake and help with cooling in hot humid environments.

• Other cooling strategies are very important to prevent heat stroke in hot conditions. These include staying in the shade during breaks and removing warm jerseys, using cold-water ice packs and side-line fans.

Dehydration, over-hydration and cognitive skills

Both dehydration and over-hydration can impact on cognitive skills and performance. Early signs of dehydration include head-ache, fatigue, loss of appetite, flushed skin, heat intolerance, light-headedness, dry mouth and eyes, and dark urine with a strong odour. Advanced signs require urgent medical intervention and include difficulty in swallowing, clumsiness, shrivelled skin, sunken eyes and dim vision, painful urination, numb skin, muscle spasms, ‘abnormal behaviour’ and delirium.

Over-drinking, even in team sports, has been reported:

American football players, in an attempt to prevent heat cramps, over-hydrated by drinking too much water. Signs of over-hydration include nausea, vomiting, extreme fatigue, respiratory distress, dizziness, confusion, disorientation, oedema (rings, shoes, watches may feel tight), coma, seizures, and even death if left untreated.

Alcohol

Alcohol, by impacting on metabolic, cardiovascular, thermoregulatory and neuromuscular systems, can have profound negative effects on performance. Skill and behavioural changes like reduced reaction time

and poor judgements, impaired balance, accuracy, hand–eye coordination, strength, power and endur-ance are associated with alcohol intake. Athletes cel-ebrating or commiserating after a game with alcohol may be distracted from sound recovery strategies, injury treatment and sleep. Drinking alcohol after a match interferes with the recovery of the body’s carbohydrate stores, and by increasing urinary fluid losses delays rehydration. Alcohol also has a vasodila-tory effect, which can increase bleeding and swelling, thus delaying or slowing recovery of soft-tissue dam-age and rehabilitation from injury.

For an athlete needing to manage weight, it is important to consider the significant calories con-tributed by alcohol (29 kJ/g, 7 kcal/g) and its poten-tial to increase endogenous fat.

Practice tips

• Adhere to the 24-hour rule, i.e. avoid alcohol in the 24 hours before a match and in the 24 hours after a match, if any soft-tissue injuries or bruising have occurred. Some teams may have a ban on alcohol intake!

• Ensure that plenty of non-alcoholic drinks are available after training or a match. Those players who choose to drink alcohol should first see that they are adequately rehydrated and refu-elled with carbohydrates and fluid before drinking alcoholic drinks, which in any case should be limited.

Caffeine

One of caffeine’s primary sites of action is the central nervous system and it has been shown to affect cogni-tive performance in different modes of exercise (endurance, high-intensity intermittent and strength–

power). Studies have shown that moderate doses of caffeine can result in several advantageous improve-ments important for team sports like football, field hockey and rugby, including a 10% improvement in ball-passing accuracy with a caffeine intake of 6 mg/kg, and maintenance of sprint times.

However, caffeine can be a double-edged sword.

It may increase arousal, but as a central nervous stim-ulant it can be counter-productive by also increasing nervousness and anxiety and may cause palpitations, headaches, visual disturbances and dehydration.

Some individuals are more sensitive to the effects of caffeine; this may be related to habitual intake, gen-der, type of exercise, level of training, and body weight. More is also not necessarily better. Several studies have shown that significant improvements in

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performance can be achieved with doses as low as

performance can be achieved with doses as low as