Br J Sports Med 1998;32:107–110 107 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 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 com- petition. 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 spe- cific 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 ath- lete 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 infec- tion. 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 creased whenever the mood state improved and reduced whenever it deteriorated. The inci- dence of burnout, which was previously around 10% per year, was reduced to zero. The mood state is most significant if it does Enforced rest not improve during tapering in the lead up to a competition, but unfortunately it may then be Figure 2 Cycle of recurrent minor infections. too late to prevent underperformance. The Overtraining syndrome 109

advice is therefore to taper and recover Thus a decrease in levels of branched chain regularly throughout the season to enable amino acids in the blood as the result of an regular monitoring of recovery. increased rate of utilisation by muscle will At the British Olympic Medical Centre we increase the ratio of tryptophan to branched have shown that both performance and mood chain amino acids in the bloodstream and state improve with five weeks of physical rest. favour the entry of tryptophan into the brain. Low level exercise has also been shown to This may result in fatigue originating in the speed recovery from chronic fatigue brain. Free tryptophan is further increased by a syndrome.11 rise in plasma fatty acid levels. In endurance activity, non-esterified fatty acids increase and HORMONAL CHANGES branched chain amino acids decrease. In rats it The role of hormones in the overtraining has been shown that this increases the concen- syndrome is still not fully understood. Stress tration of 5HT in the hypothalamus and hormones, such as adrenaline and cortisol, brainstem.26 have been shown to be increased in overtrained 5HT-containing cells are widespread in the athletes compared with controls. Salivary central nervous system, and changes in 5HT cortisol levels (reflecting free cortisol levels) in levels could account for many of the symptoms a group of swimmers were significantly higher of overtraining aVecting sleep, causing central in stale underperforming athletes, and this cor- fatigue and loss of appetite, and inhibiting the related with the depressed mood state.19 release of factors from the hypothalamus that A low testosterone:cortisol ratio has been control pituitary hormones.27 28 suggested as a marker of the overtraining syndrome, reflecting a change in the balance of IMMUNOSUPPRESSION AND GLUTAMINE anabolism to catabolism. This ratio also falls in There is evidence that moderate regular response to overreaching, so only a very low exercise helps to reduce the level of infection in ratio is useful. In some athletes there is no sig- normal individuals. However, intense heavy nificant change, despite all the symptoms of the exercise increases the incidence of infection.29 overtraining syndrome.19 There is one report of Upper respiratory tract infections have been the (prohibited) use of anabolic steroids to shown to be more likely with higher training treat the overtraining syndrome.20 mileage30 and after a marathon.31 A number of A reduced response to insulin induced hypo- factors probably contribute to this apparent glycaemia was shown by Baron and Noakes immunosuppression, such as raised cortisol and colleagues21 suggesting hypothalamic dys- levels, reduced salivary immunoglobulin levels, function. and low glutamine levels. Glutamine is an Noradrenaline levels have been shown to be essential for rapidly dividing cells higher in overtrained swimmers than in con- such as lymphocytes. Low levels of glutamine trols, particularly during tapering, but levels have been found in overtrained athletes com- were generally proportional to the training pared with controls, and levels are known to be stress. There was no change in cortisol levels.22 lower after hard training.32 Plasma catecholamine levels and stress ratings Glutamine intervention studies have been (assessed by questionnaire) were a useful carried out and there is some evidence that the predictor of staleness, and a well being rating incidence of infection after prolonged exercise questionnaire during tapering predicted in endurance athletes taking glutamine is performance.23 reduced compared with those taking placebo.33 The rise in noradrenaline levels and fall in basal nocturnal plasma , noradrena- Management line, and adrenaline levels have been proposed Athletes suVering from chronic fatigue and as a method of monitoring overtraining. These underperformance are diVerent from seden- levels correlate with symptoms.24 tary individuals because they present earlier, they tend to recover more quickly, and there is CENTRAL FATIGUE an opportunity to alter the major stress in their The British Olympic Medical Centre has lives (training and competition). Nevertheless, shown that overtrained athletes produce a management is similar to that for any indi- lower peak power in 20 second Wingate sprint vidual with chronic fatigue and requires a tests and weaker isometric and concentric holistic approach. Rest and regeneration quadriceps contractions than do controls. strategies are central to recovery.1 Superimposed tetanic stimulation produced a If told to rest, athletes will not comply. So rise in isometric power. This suggests that there they should be given positive advice and told to is central fatigue with a failure to activate fast exercise aerobically at a pulse rate of 120–140 twitch muscle fibres fully and is consistent with beats per minute for five to ten minutes each the history of an inability to lift the pace at the day, ideally in divided sessions, and slowly end of a race and to sprint for the line.25 build this up over 6–12 weeks. The exercise programme has to be individually designed and AMINO ACIDS AND CENTRAL FATIGUE depends on the clinical picture and rate of The neurotransmitter 5-hydroxytryptamine improvement. The cycle of partial recovery fol- (5HT, serotonin) may be important in tired- lowed by hard training and recurrent break- ness and sleep. The amino acid tryptophan is down needs to be stopped. It is often necessary converted in the brain into 5HT and competes for athletes to avoid their own sports, and cross with the branched chain amino acids for entry training should be used because of the into the brain on the same amino acid carrier. tendency otherwise to increase exercise 110 Budgett

intensity too quickly. A positive approach is 4 Morton RH. Modelling training and overtraining. J Sports Sci 1997;15:335–40. essential, with an emphasis on slowly building 5 Budgett R. The overtraining syndrome. Br J Sports Med up volume rather than intensity to about one 1990;24:231–6. hour per day. Once this volume is tolerated, 6 Morgan WP, Costill DC, Flynn MG, et al. Mood disturbance following increased training in swimmers. Med then more intense work can be incorporated Sci Sports Exerc 1988;20:408–14. above the onset of blood lactate 7 Costill DL, Flynn MG, Kirway JP, et al.EVects of repeated 18 days of intensified training on muscle glycogen and accumulation. swimming performance. Med Sci Sports Exerc 1988;20: Very short (less than 10 seconds) sprints/ 249–54. 8 Smith C, Kirby P, Noakes TD. The worn-out athlete: a power sessions with at least three to five clinical approach to chronic fatigue in athletes. J Sports Sci minutes of rest are safe and allow some hard 1997;15:341–51. training to be carried out. 9 Fry RW, Morton AR, Keast D. Periodisation and the prevention of overtraining. Can J Sports Sci 1992;17:241–8. There have been no trials of the regeneration 10 Dyment P. Frustrated by chronic fatigue? Physician and strategies widely used in the old Eastern Block Sports Medicine 1993;21:47–54. 25 11 Koutedakis Y, Budgett R, Faulmann L. Rest in underper- countries. These include rest, relaxation, forming elite competitors. Br J Sports Med 1990;24:248– counselling, and psychotherapy. and 52. 12 Kindermann W. Das Ubertraining-Ausdruck einer vegeta- hydrotherapy are used and nutrition is looked tiven Fehlsteurung. Deutsche Zeitschrift fur Sportsmedizin at carefully. Large quantities of and 1986;37:138–45. supplements are given, but there is no evidence 13 Budgett R. The overtraining syndrome. Coaching Focus 1995;28:4–6. that they are eVective. Stresses outside sport 14 Morgan WP, Brown DR, Raglin JS, et al. Psychological are reduced as much as possible. Occasionally, monitoring of overtraining and staleness. Br J Sports Med 1987;21:107–14. depression may need to be treated with anti- 15 Dressendorfer RH, Wade CE, ScaV JH. Increased morning depressants but normally drugs are of no value, heart rate in runners: a valid sign of overtraining? Physician and Sports Medicine 1985;13:77–86. although any concurrent illness must be 16 Morton RH. The quantitative periodisation of athletic treated. training: a model study. Sports Medicine: Training and Reha- Athletes who have been underperforming for bilitation 1991;3:19–28. 17 Fry AC, Kraemer WJ. Does short-term near-maximal many months are often surprised at the good intensity machine resistance training induce overtraining? performance they can produce after 12 weeks Journal of Strength and Conditioning Research 1994;8:188– 91. of extremely light exercise. At this point, care 18 Synder AC. A physiological/psychological indicator of over- must be taken not to increase the intensity of reaching during intensive training. Int J Sports Med training too fast and to allow full recovery after 1993;14:29–32. 19 Flynn MG, Pizza FX, Boone JB, et al. Indices of training hard parts of the training cycle. We recommend stress during competitive running and swimming seasons. that athletes recover completely at least once a Int J Sports Med 1994;15:21–6. 20 Kereszty A. Overtraining. In: Larson L, eds. Encyclopedia of week. sports science and medicine. New York: MacMillan, 1971: 218–22. 21 Barron JL, Noakes TD, Levy W, et al. Hypothalamic Summary dysfunction in overtrained athletes. J Clin Endocrinol Metab The overtraining syndrome aVects mainly 1985;60:803–6. endurance athletes. It is a condition of chronic 22 Hooper SL, Mackinnon LT, Gordon RD, et al. Markers for monitoring overtraining and recovery. Med Sci Sports Exerc fatigue, underperformance, and an increased 1995;27:106–12. vulnerability to infection leading to recurrent 23 Hooper SL, Mackinnon LT. Monitoring overtraining in ath- letes. Sports Med 1995;20:231–7. infections. It is not yet known exactly how the 24 Lehmann M, Dickhuth HH, Gendrisch E, et al. Training- stress of hard training and competition leads to overtraining. A prospective experimental study with experienced middle and long distance runners. Int J Sports the observed spectrum of symptoms. Psycho- Med 1991;12:444–52. logical, endocrinogical, physiological, and im- 25 Koutedakis Y, Frishknecht R, Vrbová G, et al. Maximal vol- munological factors all play a role in the failure untary quadriceps strength patterns in Olympic over- trained athletes. Med Sci Sports Exerc 1995;27:566–72. to recover from exercise. 26 Blomstrand E, Hassmen P, Newsholme EA. Administration Careful monitoring of athletes and their of branched-chain amino acids during sustained exercise. Eur J Appl Physiol 1991;63:83. response to training may help to prevent the 27 Blomstrand E, Perrett D, Parry-Billings M, et al.EVect of overtraining syndrome. With a very careful sustained exercise on plasma amino acid concentrations and on 5-hydroxtryptamine metabolism in six diVerent exercise regimen and regeneration strategies, brain regions in the rat. Acta Physiol Scand 1989;136:473. symptoms normally resolve in 6–12 weeks but 28 Rang HP, Dale MM. Pharmacology. London: Churchill Liv- may continue much longer or recur if athletes ingstone, 1987. 29 Nieman D. Exercise infection and immunity. Int J Sports return to hard training too soon. Med 1994;15:S131. 30 Heath GW, Ford ES, Craven TE, et al. Exercise and the incidence of upper respiratory tract infections. Med Sci I would like to thank my secretary Susan Wheeler for all her help Sports Exerc 1991;23:152–7. with producing this review article. 31 Nieman D, Johanssen LM, Lee JW, et al. 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