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RESPIRATORY ILLNESS & SOCCER PERFORMANCE
 
INTRODUCTION & CAUSES
 

You wake up one morning feeling terrible, you have a headache, sore throat, your chest feels congested and your breathing is affected. You know you have a cold or flu which are both caused by viruses. This experience has happened some time or other to many soccer players at all levels of the game. As Liesen who worked for the German National Team during major competitions such as the World Cup & European Championships mentions, "a stable top-level performance is only possible in combination with a stable psychological, neurological, endocrinological and immunological state of health". Any insufficiency in either of these areas leads to a higher susceptibility to illness or injury.

It has been proved that athletes who train moderately are less likely to be ill due to a strengthening of the immune system. However, those undergoing intensive hard training are more at risk of catching an upper respiratory tract infection such as colds or flu. This is due to the effect on Lymphocytes which are the white blood cells involved in fighting disease. Within 30 minutes of recovery after exercise, the bodies' lymphocyte count dips 30 - 50% below pre-exercise levels, and remains low for 3 - 6 hours thus leaving the player open to illness. The reduction in Lymphocyte levels is dependent on hormones such as adrenaline and cortisol which are produced in higher quantities during intensive exercise. Exercising in the heat, at altitude and dehydration may depress the immune function further.

Carbohydrate depletion is also linked to illness thus players who have low carbohydrate intake and do not replenish their body stores will be at risk. Generally poor diet with a lack of vitamins and minerals is also a factor involved in illness. Other factors increasing the risk of illness are contact with other athletes who may be poorly (especially straight after training )as well as poor personal hygiene and not enough sleep. Training sessions lasting more than 2 hours per session can also cause a depression of the immune system.

Finally, there is also a link between psychological stress and the immune system. During moments of psychological and emotional stress (often the case in professional soccer) there is again an increase in circulating hormones, which will have a detrimental effect on the immune system. Furthermore, during matches there is often much psychological stress, which might further affect the immune system.

 
PREVENTION & CURE
 

The main aim of the player, coach and team physician as with injury is prevention. An excellent practical example of this being the work of Liesen (mentioned above). During preparatory periods of the German Team, he concentrated on correct nutritive methods such as the substitution of vitamins, minerals, trace elements along with a well-balanced diet. Their training sessions involved mainly regenerative work loads based on a few technical/tactical repetitions lasting 2-3 minutes with regular 3-5 minute active recovery periods. Every 5 minutes, the players were given a mineral water drink enriched with trace elements and vitamin C to prevent dehydration which reduces performance capacity.

Otherwise, there are several preventative measures recommended by experts. Firstly, avoid training sessions lasting more than two hours and allow players sufficient recovery time between training and competitive matches. Overtraining will result in under-performance. Stopping suddenly after a hard session is one of the worst things you can do. End your session gently with a steady decrease in exercise intensity, followed by a few minutes stretching. Don't allow yourself to get cold - put on an extra layer of clothing if necessary. Replace fluid and energy lost during the exercise session with an isotonic sports drink or water and plenty of carbohydrates.

Also, for the first few hours after exercise, try to keep away from others with coughs and colds. Players should avoid sharing drinking bottles and ensure they have good general hygiene levels. Coaches and team doctors might consider anti-flu vaccinations.

Diet is crucial in maintaining peak performance. Ensure that athletesí diet provides them with adequate energy, carbohydrate and protein. Many vitamins and minerals help to fight infection, particularly vitamin C, vitamin A and zinc. A good, well-balanced diet should provide all the necessary vitamins and minerals players need. If fresh fruit and vegetables are not readily available, supplements may be considered. However do not overdo them as some supplements such as zinc can have immunosuppressive effects if taken in excessive amounts. Recently, glutamine (a non essential amino acid) has been shown to improve immune response following exercise and zinc supplements are shown to improve the immune system although more research is needed.

Curing colds and flu is never easy. Firstly, should the athlete train when ill ? Experts generally state no, unless you have something very minor. Training with a cold or virus can sometimes do serious long-term damage to the body, and taking a couple of days off may well help to speed up recovery from the illness itself. If the player has a fever then it is not advisable to train as the body temperature will already be higher than normal and will result in reduced performance and even heat stroke. However, very light exercise during convalescence may enhance recovery. Recovering athletes should not resume training at the same level but build up gradually.

As for treating the illness, your Doctor or a qualified Pharmacist are the best people to advise on the course of treatment (antibiotics, vitamins, herbal remedies, fluid intake...).

 
CONCLUSION
 

Many soccer players will miss games through illness such as colds or flu. Exercise scientists have shown that as individuals increase their total training load, the risk of respiratory infection also mounts. The risk of illness can be reduced by adhering to a strict post-exercise routine along with a good diet. Learning to manage psychological stress is also important in reducing the chances of being poorly as is a good lifestyle. Continuing to train whilst ill is generally not recommended by experts. However, if in doubt about or before following any of the points mentioned above, consult your Doctor as this information is not designed to replace the advice of a medical expert and it is only he or she who can decide on what is best for you !

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