We’ve all heard of overtraining, also known as overtraining syndrome (OTS), staleness, chronic fatigue in athletes, sports fatigue syndrome and burnout (Budgett et al. 2000, Lakier Smith 2003).
OTS should not be confused with over-reaching which reflects a temporary deterioration in athletic performance or short-term fatigue (Urhausen & Kindermann 2002). With sufficient rest, the over-reached athlete should recover and show improvement (Lakier Smith 2003). However if the intensity and duration of training are not reduced, this could lead to OTS. One of the main differences between over-reaching and OTS is in their recovery times. Recovery from over-reaching should take 2 to 3 weeks whilst OTS recovery could take several months (Petibois et al. 2002).
The exact aetiology of OTS is not fully understood and there is no universal tool to predict its occurrence before it is clinically diagnosed (Petibois et al. 2002). A number of hypotheses have been proposed in an attempt to explain the condition of overtraining syndrome (OTS), however the underlying mechanism(s) remains unclear. Many researchers agree that it is related to a dramatic increase of, or sustained periods of, high volume and/or intensity of training/competition with insufficient time for recovery (Lakier Smith 2003). Yet, some would argue that looking at factors outside the specific training environment, such as relationships between the athlete and the coach or personal relationships, are important as these could be a significant variable in OTS (Budgett et al. 2000, Mackinnon 2000).
The prevalence of OTS is difficult to estimate (Mackinnon 2000), hindered by unsystematic research with large variances in protocols from study to study (Mackinnon 2000,Uusitalo 2001). This has resulted in the very existence of overtraining being questioned (Halson & Jeukendrup 2004). In an attempt to clarify the diagnostic criteria to be used in the future a round table discussion was held in 1999 at St. Catherine’s College, Oxford to clarify the diagnostic criteria to be used in the future(Budgett et al. 1999). It was decided to redefine the syndrome as unexplained underperformance syndrome (UPS) defined as ‘a persistent unexplained performance deficit (recognised and agreed by coach and athlete) despite two weeks of relative rest’. This was said to be a broad and all inclusive definition which does not include over-reaching.
It is postulated that UPS is associated with suppressed immune function. This is associated with increased incidence and severity of upper respiratory tract infections (URTIs). There have also been reports of intestinal upsets, slow wound healing and increased sensitivity to environmental and food allergens. Alteration in immune cell function has also been recorded which include suppressed neutrophil function, suppressed lymphocyte count and proliferation, suppressed natural killer cell count and activity and decreased serum, nasal and salivary immunoglobulins (Dorshkind & Horseman 2001, Lakier Smith 2003).
Impaired mood state and subjective complaints are consistently described as sensitive and early markers of UPS and these usually start well before a definitive drop in performance (Urhausen & Kindermann 2002). Other signs and symptoms include the following:
decreased muscular strength
loss of coordination
loss of appetite
difficulty in concentrating
fear of competition
increased susceptibility to illnesses
minor scratches heal slowly
negative nitrogen balance
depressed muscle glycogen concentration
mineral depletion i.e. zinc, cobalt, aluminium, selenium, copper
low free testosterone
Athletes display different combinations of these symptoms with varying degrees of severity.
(McKenzie 1999, Lakier Smith 2000, Petibois et al 2002, Lakier Smith 2003)
Several factors contribute to UPS, including a sudden increase in training volume and or intensity, heavy competition schedule, lack of periodisation, monotonous training programme, lack of programmed recovery and high self-reported stress levels regardless of whether they are directly related to training (Mackinnon 2000).
A 41-year-old female professional dressage rider and trainer presented with the following:
Lethargy, apathy, loss of appetite as well as an intolerance to numerous foods, tiredness all day and especially after light exercise, anxiety (related to loud noises and to normal daily tasks that would otherwise have posed no problem), an inability to concentrate or make decisions, poor memory, palpitations, mood swings and a need to be left alone.
This was affecting her riding as dressage demands constant mental focus and alertness. As a result, she was unable to perform the simplest task with her horse. She found it impossible to remember everything she had to do to keep her posture as well as signal to her horse for him to perform a particular exercise.
She slept whenever she could and kept away from people feeling unable and unwilling to socialise.
Her blood test showed nothing out of the ordinary and a past history of her training regime did not show any change in training volume with ample recovery time. Her diet history showed that she normally had an excellent appetite and ate a fairly varied diet as she ‘liked everything’.
However in the last 18 months she moved to a new property which needed to be completely renovated and also sold several of her horses and moved to a new stable. All three incidences were highly stressful, each was laden with problems and it appeared she may not have been adapting to the stress.
An Adrenal Stress Index (ASI) test was recommended to ascertain her levels of cortisol. The results showed low noon cortisol levels whilst her afternoon levels dropped below the reference range. This is known as pre-exhaustion or pre-adrenal fatigue. This pattern indicates long-term stress which depletes the adrenal glands caused by an excess cortisol response (Raber 1998).
After a 6 week period, following a protocol of supplements to support the adrenal glands and help balance blood sugar levels, the subject regained her energy, appetite, mental concentration, memory and for the first time in over 10 years, was able to wake up relatively early each morning without an alarm and full of energy. Her own dressage training improved above her own expectations as she was able to multitask and keep her concentration.
Despite the fact that high cortisol has been recorded in some athletes with UPS, very little research is available on how to lower cortisol levels besides rest periods of several months.
Chronic secretions of cortisol need to be addressed as they can lead to the following:
-a weakening of the immune system making the athlete more prone to bacterial and viral infections. This is due to the adrenal glands using up large quantities of zinc, B vitamins and vitamin C, all of which are needed for optimal immune function, but are shown to be deficient in long-term stress.
-a depletion of zinc and B6, which are needed to make hydrochloric acid (HCl) in the stomach. A decrease in HCl production results in the incomplete digestion of foods (especially proteins). As such, absorption is marginalised.
-an increase of fat in the abdominal area.
-an increase in protein breakdown leading to a loss of muscle tone.
-an inability to heal wounds due to a depletion of zinc.
-increased sleep problems.
-an inability to focus mentally as memory is impaired.
-an increased possibility of insulin resistance which can lead to diabetes.
(Raber 1998, McKenzie 1999, Budgett et al. 2000, Lakier Smith 2000, Mackinnon 2000, Dorshkind & Horseman 2001, Kenttä et al. 2001, Urhausen & Kindermann 2002, Venkatraman & Pendergast 2002, Petibois et al. 2003, Steinacker et al. 2004, Uusitalo et al. 2004).
Although not all athletes with UPS will present with chronically high levels of cortisol, for those who do, a simple non-invasive saliva test can accurately reflect levels of Cortisol. Clinical evidence shows a return to normal function in as little as 6 weeks or as much as 9 months. Certainly more research is needed in this area but for the time being, for athletes showing signs of UPS and after excluding any form of disease or psychological problems, a simple saliva test may be worth considering.
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