Reduced performance and undue tiredness are quite common complaints among athletes and gym attendees. Doctors, coaches and nutritionists are often confronted with athletes who are feeling excessively tired and are often uncertain as to whether they should be pushing themselves to train harder or whether they would be best to rest. They often worry about losing the level of performance and fitness that they have worked so hard to achieve.

There are many causes for an athlete's fatigue, some of which include:

• Inadequate sleep - This may be related to excessive time pressures on athletes who often have to fit in full-time employment or study with an excessive training schedule. Other factors may be anxiety related to sport, team selection or financial, family or relationship problems.
• Inadequate diet - e.g. dehydration, deficiency of fuel sources (carbohydrates and fats), of protein or micronutrients such as zinc, chromium, B12, and magnesium. The athlete must adapt his/her diet to changes in weather, altitude, training, playing schedules and travel. A Sports Nutritionist is of major assistance in this area.
• Illness - Athletes may be more susceptible to viruses and infections due to a lowered immune system from excessive training.

One particularly relevant and important cause of fatigue in the athlete is the "Overtraining Syndrome".

This is a state of chronically diminished performance, which manifests itself through persistent tiredness and staleness. Both excessive training load (doing too much, too hard) and inadequate recovery time (not enough day's rest) may result in overtraining syndrome. If this is recognised early and adequate rest is initiated the symptoms subside as the body recovers and a graduated training program can recommence. If the athlete however pushes on with training this serious syndrome may set in and recovery may take months. Early recognition and early rest can prevent overtraining syndrome.

Many factors affect the body's muscular, cardiovascular, physiological immunological and hormonal systems in this condition. These include:

• Muscular affects - Muscle soreness and weakness occur and are more persistent than usual after even moderate exercise. Biochemical tests can reveal evidence of muscle cell damage by detecting enzymes released from inside damaged cells into the bloodstream. Overuse injuries consequently can occur more readily and further reduce performance.
  "Easy" muscle fatigue - Due to reduced muscle energy (glycogen) storage and is evident by the athletes reduced ability to perform repetitive exercises which were previously easily achieved.
• Cardiovascular affects - These can be varied and troublesome, the most obvious of which is a raised resting heart rate, which can be easily self monitored by the athlete counting their pulse rate upon waking each morning. After a given exercise the heart rate and blood pressure may also be significantly higher and will take longer to return to normal levels after a cool down post exercise.
• Immunological changes - Recurrent infections, e.g. colds, cold sores, skin infections and flu can occur as the result of the affect of overtraining on the body's immune system. These abnormalities can be detected through blood tests.
• Psychological affects - These are a prominent factor in the athletes presenting symptoms and sometimes people feel uncomfortable about discussing these. Therefore it is important for the person dealing with the athlete to discreetly enquire about such feeling as irritability, general fatigue, reduced concentration and motivation, anxiety, depression and sleep disturbances.
• Hormonal changes - These are also often a reason to seek assistance, especially in females when irregular periods often occur. Changes in cortisol (the body's natural anti-inflammatory) are also measurable. Reduction in the male sex hormone, testosterone, may result in a reduced sex drive.

Awareness, early recognition and appropriate rest are all important. Prevention of this condition involves a carefully planned diet, training and competition schedule.

Regular medical screening, to ascertain baseline readings for heart rate, blood pressure, lung function, as well as urine and blood analysis (to test levels of creatinine, iron, B12, folate, B6, zinc, blood glucose levels, red and white blood cell count etc) should be carried out for athletes who are training at the top level required for competition.

A carefully planned diet and supplement program, specifically designed by a sports nutritionist, should be formulated taking considerations such as the sport, training regimes required and the competitive season so as to maximise performance and reduce risk of overtraining.

A training schedule should be varied, with some weight bearing activities such as weight training and running as well as non weight bearing such as swimming and cycling. This will enhance fitness levels whilst reducing boredom and the overuse of specific muscle groups and tendons. Also periodisation should be included, that is periods of training that include intense hard work to develop strength and fitness along with periods of lighter work that may put the emphasis on learning specific skills and co-ordination. These periods of "active rest" enable the body to recover from the constant strain of intense training. Also it is important to have a balanced lifestyle that includes time away from work and sport to ensure adequate rest, relaxation and sleep.

This requires total rest, the duration of which depends on how early the syndrome is recognised. Early recognition and intervention necessitates briefer periods of rest. Diet is also a very important factor that needs to be addressed. Psychological support is also important and this requires close liaison between the coach, nutritionist, therapist, athlete and other members of the athlete's team.