Fatigue and Underperformance in Athletes: the Overtraining Syndrome

Br J Sports Med 1998;32:107–110 107 Fatigue and underperformance in athletes: the overtraining syndrome Richard Budgett Introduction Intensive interval training, in which one to When athletes fail to recover from training they six minutes of hard exercise is repeated several become progressively fatigued and suVer from times with a short rest, is most likely to precipi- prolonged underperformance. They may also tate the overtraining syndrome. There may also suVer from frequent minor infections (particu- be a history of a sudden increase in training, larly respiratory infections). In the absence of prolonged heavy monotonous training, and any other medical cause, this is often called the very commonly some other physical or psycho- overtraining syndrome, burnout, staleness, or logical stress. Nevertheless, however hard the chronic fatigue in athletes.1–3 The condition is training, most athletes will recover fully after secondary to the stress of training but the exact two weeks of adequate rest. The cyclical nature cause and pathophysiology is not known. Many of most training programmes (periodisation) factors may lead to failure to recover from allows this recovery and full benefit from hard training or competition. exercise.9 Figure 1 summarises the responses to training. Definition Eventually fatigue becomes so severe that “The overtraining syndrome is a condition of recovery does not occur despite two weeks of fatigue and underperformance, often associ- relative rest. At this stage a diagnosis of the ated with frequent infections and depression overtraining syndrome can be made. which occurs following hard training and competition. The symptoms do not resolve despite SYMPTOMS two weeks of adequate rest, and there is no The main complaint is of underperformance. other identifiable medical cause.” Athletes will often ignore fatigue, heavy This contrasts with the definition of chronic muscles, and depression until performance is fatigue syndrome, for which symptoms must chronically aVected.10 Sleep disturbance occurs last at least six months.1 in over 90% of cases with diYculty in getting to sleep, nightmares, waking in the night, and Normal response to training waking unrefreshed.11 There may also be loss of All athletes, in any sport, must train hard in appetite, weight loss, loss of competitive drive order to improve. Initial hard training causes and libido, and increased emotional ability, underperformance but if recovery is allowed, anxiety, and irritability. The athlete may report there is supercompensation and improvement a raised resting pulse rate and excessive sweat- in performance.4 Training is designed in a ing. Upper respiratory tract infections or other cyclical way (periodisation) allowing time for minor infections frequently recur every time an recovery with progressive overload. During the athlete tries to return to training when they hard training/overload period, transient symp- have not fully recovered. This gives an apparent toms and signs and changes in diagnostic tests cycle of recurrent infection every few weeks (fig may occur; this is called overreaching.5 2).1 There are changes in the profile of mood state (POMS) questionnaire which show re- SIGNS duced vigour and increased tension, depres- Reported signs are often caused by associated sion, anger, fatigue, and confusion.6 Muscle illness and are inconsistent and generally glycogen stores are depleted and resting heart unhelpful in making the diagnosis. Cervical rate rises. The testosterone:cortisol ratio is lymphadenopathy is very common. There may reduced as the result of lower testosterone and be an increased postural fall in blood pressure higher cortisol levels. Microscopic damage to and postural rise in heart rate, probably related muscle also leads to raised creatine kinase lev- to the underlying pathophysiology.12 Physi- els if there is eccentric exercise.7 ological testing may show a reduced maximum All these changes are physiological and nor- oxygen consumption and maximum power British Olympic mal if recovery occurs within two weeks. Over- output and an increased submaximum oxygen Medical Centre, reaching is a vital part of training for improved consumption and pulse rate, with a slow return Northwick Park performance.5 of the pulse rate to normal after exercise.11 Hospital, Watford Road, Harrow, Abnormal response to training PREVENTION AND EARLY DETECTION Middlesex HA1 3UJ, United Kingdom In some athletes there is underrecovery as the Overtraining for one athlete may be insufficient R. Budgett result of excessively prolonged and/or intense training for another. Athletes tolerate diVerent exercise, stressful competition, or other levels of training, competition, and stress at Correspondence to: stresses. This leads to progressive fatigue and diVerent times, depending on their level of Dr R Budgett. underperformance. The reaction to this under- health and fitness through the season. The Accepted for publication performance is often an increase in training training load must therefore be individualised 10 March 1998 rather than rest.8 and reduced or increased, depending on the 108 Budgett Normal periodisation of training CLINICAL INVESTIGATIONS Athletes presenting with chronic fatigue and underperformance are often looking for a specific diagnosis and expect investigations. There Quick is no diagnostic test available, so the aim of recovery Time still possible clinical investigations must be to exclude other with rest causes of chronic fatigue and reassure the athlete that there is no serious pathology. The Overreaching Performance range of any test depends on a sensible (quickly reversable symptoms) Underrecovery approach to clinical possibilities, guided by the history and examination. A routine haemato- logical screen may be all that is necessary, but Prolonged recovery needed below this line occasionally more extensive investigations are Overtraining syndrome justified to exclude serious disease such as viral (prolonged symptoms) myocarditis and arrhythmia. Figure 1 Overtraining or underrecovery, leading to the overtraining syndrome. A history of recurrent upper respiratory tract infections may represent allergic rhinitis or athlete’s response. Other stresses such as exams 13 exercise induced asthma, in which case lung need to be taken into account. function tests are needed.8 Creatine kinase lev- In practice it is very diYcult to distinguish els are often very high in athletes, and the rise between overreaching and the overtraining is proportional to the intensity, volume, and syndrome. Researchers have attempted to type of exercise (particularly eccentric work).12 follow blood parameters such as haemoglobin, Unfortunately, creatine kinase cannot be used packed cell volume, and creatine kinase but to indicate who will fail to recover from hard these do not help. Mood state profiling on a training. Many athletes also have a low packed regular basis can give useful guidance.14 cell volume and relatively low haemoglobin. Many athletes monitor their heart rate. This This athletic anaemia is physiological; it is due is non-specific but can provide objective to haemodilution and does not aVect perform- evidence that something is wrong.15 Other pre- ance. vention strategies are a good diet, full hydra- The history may suggest a post-viral illness. tion, and rest between training sessions. It is To make a firm diagnosis, viral titres must be more diYcult for athletes who have a full time shown to rise. There may also be reactive lym- job and other commitments to recover quickly phocytes, and a positive Paul-Bunnell test is after training. highly suggestive of Epstein-Barr viral infection. Because it is very diYcult to predict which Many athletes use supplements, but these do athletes will slip into an overtrained state not seem to oVer any protection from chronic during a period of prolonged overreaching, it is fatigue. Trace elements and minerals such as prudent to allow full recovery at least every two magnesium have been investigated, but there is weeks. Many sports scientists and coaches are no proven link to the overtraining syndrome.5 advising alternate-day hard and light training within the normal cyclical programme.9 Training intensity and spacing of the training Pathophysiology are the most important factors in optimising TRAINING AND PSYCHOLOGY performance and minimising the risk of Fry et al17 tried to induce overtraining by short overtraining. Morton16 used a complex math- near maximum high intensity exercise but ematical model to optimise periodisation of failed, suggesting that this is a safe regimen. athletic training. In this he suggested intensive This may be because of the frequent long peri- training on alternate days over a 150 day ods of rest between eVorts. This supports our season, with a build up over the first half taper- own observations that sprinters and power ath- ing oV over the second half. This was more letes do not suVer from the overtraining eVective than moderate training throughout syndrome. the whole year. Other researchers have shown a fall in the “lactate:rating of perceived exertion” ratio with heavy training.18 Thus, for a set lactate level, the Hard training and perceived exertion is higher, but this may competition represent glycogen depletion causing lower lactate levels rather than the overtraining Stresses/infection syndrome. The POMS questionnaire was used on a group of collegiate swimmers in the United Underperformance, States by Morgan .14 Training was in- Partial recovery et al fatigue and infection

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