Overtraining Syndrome

A Guide to Diagnosis, Treatment, and Prevention

Christopher J. Hawley, MD; Robert B. Schoene, MD

Practice Essentials Series Editors:
Kimberly G. Harmon, MD; Aaron Rubin, MD

THE PHYSICIAN AND SPORTSMEDICINE - VOL 31 - NO. 6 - JUNE 2003

In Brief: Overtraining syndrome is a common cause of underperformance in athletes. Symptoms such as persistent fatigue, muscle soreness, reduced coordination, weight loss, mood changes, and frequent illness may accompany performance decrements, but they may also be signs of underlying medical conditions. Reliable and practical diagnostic laboratory tests for overtraining have not yet been identified. Clinicians can prescribe relative or complete rest and strive to identify and correct the training, nutritional, and psychosocial factors that contributed to the athlete's condition.

Overtraining syndrome can be a devastating condition for any athlete, because recovery requires an extended period away from training and competition. Evaluating and treating a persistently fatigued and underperforming athlete for overtraining syndrome can be challenging. Frequently, overtraining syndrome is not recognized until months of poor performance and fatigue have occurred. The diagnosis is difficult, because numerous other medical and psychological conditions have similar symptoms. Overtraining syndrome can only be diagnosed after other causes have been excluded.

The existence of the condition has been well documented in the scientific literature and in many excellent reviews.^1-4 However, reliable and clinically practical tests for diagnosis have not been established, and the underlying mechanism for the performance decrements is not known.^5,6 Further research is needed to provide evidence-based diagnostic, treatment, and return-to-play approaches to this complex condition.

Definitions

Vigorous training, followed by recovery, is essential for improving athletic performance. Some level of fatigue, depression, feelings of burnout, anxiety, irritability, and difficulty concentrating or sleeping is normal for athletes undergoing heavy training or competition. Athletes may also experience persistent muscle soreness, decreased coordination, reduced libido, and frequent upper respiratory infections.⁷ This training state is termed "overreaching" and is an expected part of vigorous training.

The symptoms and reduced performance capacity of an overreached athlete resolve quickly if followed by a period of lighter training, often referred to as tapering. During tapering, the athlete's performance capacity will increase beyond the pretraining baseline, and this response is called "supercompensation." If overreaching continues for too long, overtraining syndrome can develop, and the symptoms and decreased performance ability can last for weeks to months (figure 1).

Overtraining syndrome has been defined as persistent underperforming, with or without other accompanying psychological and physical symptoms, despite 2 weeks of lighter training or complete rest.⁷ Overtraining syndrome develops when excessive physical and psychological stress are combined with inadequate recovery time. Immunosuppression, neurohormonal imbalances, and chronic inflammation may account for the observed symptoms, but the underlying mechanism is not known.^5,6

The syndrome has been documented in a wide variety of both endurance and strength or power sports. Morgan et al⁸ reported that overtraining syndrome developed in more than 60% of elite distance runners at least once in their careers. Other prevalence studies demonstrated that overtraining syndrome developed in 21% of the Australian swimming team after 6 months of training for a national competition, 33% of an Indian basketball team during a 6-week training period, and more than 50% of soccer players on a team monitored after the competitive season.⁹

Detailed History

Evaluating a fatigued athlete requires a comprehensive history and physical exam to narrow the differential diagnosis. The history should include a review of systems to screen for symptoms that could indicate life-threatening cardiac, respiratory, or infectious illnesses. Red flags include chest pain, syncope, palpitations, fevers, dyspnea, or family history of sudden cardiac death. When overtraining syndrome is suspected, the history should include the athlete's training and recovery patterns, an inventory of psychosocial stressors, and an assessment of nutritional practices.

Training and recovery. When applicable, the athlete's coach should be involved in the history taking process, evaluation, and treatment planning. Familiarity with training programs specific to a sport and the athlete's physical needs, psychological capacity, and skill level are valuable in identifying an athlete who might be training excessively. Consulting other physicians, coaches, and exercise physiologists is useful for clinicians who are unfamiliar with training patterns relevant to the athlete's situation.

Documenting the volume and intensity of training at daily, weekly, monthly, and yearly intervals is important to assess for risk factors of overtraining syndrome. Lack of recovery time in the training schedule is the most important risk factor.³ Chronologically documenting objective performance indicators will also help identify when stagnation or performance decrements began.

A daily training log to track subjective symptoms is sensitive and specific for predicting which athletes will develop overtraining syndrome.^2-4,10 Sleep quality, stress levels, fatigue, and muscle soreness are rated to monitor training responses (see the Patient Adviser, "Overtraining Syndrome: Why Training too Hard, too Long, Doesn't Work"). One study¹⁰ quantified these ratings on a 1 to 7 scale in elite swimmers. Higher scores on individual items indicated a poor response to training. Rising scores predicted overtraining syndrome 1 to 2 weeks before the actual performance declined.

Psychosocial factors. Because both sport- and non-sport-related psychological stressors contribute to overtraining syndrome, a detailed psychosocial history is necessary. Sport-related factors can include conflict with teammates, coaches, or staff and fear of competition or poor performance. Elements not related to sport include concerns regarding employment, academic studies, and family or social relationships. The amount of required sleep and other time commitments of the athlete should also be considered.

Subjective symptoms remain the most sensitive indicators of overtraining syndrome.^2-5 A variety of psychological assessment tools have been applied to overtraining syndrome. The Profile of Mood States (POMS) has been the test most frequently studied. This 65-question test provides a mood profile with scores in seven different domains: tension-anxiety, depression, anger, vigor, fatigue, confusion, and total mood.¹¹ Athletes with overtraining syndrome have higher scores for total mood disturbance, depression, tension, and decreased vigor.^2,4,8,10 The POMS test doesn't diagnose overtraining syndrome but does provide a validated method for documenting mood changes consistent with the condition.

When maintained over a season, training logs and POMS can be useful tools for athletes and coaches. Significant changes in scores and performance may indicate overtraining, but other factors such as illness, injury, technique or equipment changes, diet, travel, and psychosocial issues must also be considered. The athlete's response to a few days of rest or recovery training can often help clarify whether symptoms represent short-term overreaching, overtraining syndrome, or another cause for mood and performance changes.

Diet. Nutritional factors that contribute to the development of fatigue include dehydration and inadequate intake of complex carbohydrates, protein, vitamins, or minerals.² The history should include present and past use of medications, supplements, and ergogenic aids and screen for disordered eating patterns. Dieting practices (eg, low-carbohydrate, vegetarian, or high-protein diets) should be reviewed. A dietary record can be requested from the athlete and analyzed by the clinician or nutritionist or relevant software package.

Environment. Common causes of fatigue (table 1) include factors not related to illness. Recent travel, increases in academic or employment workload, insufficient sleep, equipment changes, and changes in training environment (eg, extreme heat, cold, or altitude) should be considered.

TABLE 1. Causes of Persistent Fatigue and Underperformance in Sports Common Caffeine withdrawal Environmental allergies Exercise-induced asthma Infectious mononucleosis Insufficient sleep Iron deficiencies with or without anemia Overtraining syndrome Performance anxiety Primary mood disorder:    Anxiety, depression, adjustment reaction Psychosocial stress Upper respiratory infection Less Common Dehydration Diabetes mellitus Eating disorders Hepatitis A, B, or C Hypothyroidism Inadequate carbohydrate or protein intake Lower respiratory infection Medication or supplement side effect:    Antidepressants, antihistamines, anxiolytics, beta-blockers Postconcussive syndrome Pregnancy Substance abuse Relatively Rare, but Important Adrenocortical insufficiencies or excess    Addison's disease    Cushing's syndrome    Tumors or hyperplasia Congenital or acquired heart disease    Arrhythmias    Bacterial endocarditis    Congestive heart failure    Coronary artery disease    Hypertrophic cardiomyopathy    Myocarditis or pericarditis Human immunodeficiency virus Intestinal malabsorption Lung disease    Chronic obstructive pulmonary disease    Restrictive disease Lyme disease Malaria Malignancy Neuromuscular disorder Renal disease Syphilis

Risk factors. Some common mistakes in training include lack of periodicity and rest days, year-round competition, and monotonous training routines. Athletes who train according to a published program of a top athlete, train without a coach or partner, or train with significantly more skilled or physically fit athletes may be headed for trouble. Frustration may tempt athletes to train more vigorously in response to plateaus or declines in performance or to train while experiencing significant psychosocial stressors. A thorough history will screen for these factors.

Thorough Physical Exam

A complete physical examination should address any underlying causes of fatigue not related to overtraining syndrome. Characteristic physical exam findings in overtraining syndrome have not been documented; however, common findings include resting heart rate changes, decreased body fat, cervical lymphadenopathy, and exaggerated blood pressure and heart rate responses to postural changes.^2-4 These findings are not consistently evident in athletes with overtraining syndrome and occur in many other medical conditions as well.

Laboratory Testing

Unfortunately, there are no sufficiently sensitive and specific diagnostic tests for overtraining syndrome. Many biologic markers for overtraining syndrome require serial measurements and comparison to baseline data. Collection must be well controlled, which is often achievable only under research conditions. Changes in laboratory parameters often don't distinguish between overreaching and overtraining syndrome.

Initial laboratory testing is useful, however, to screen for other causes of fatigue. Testing should include a complete blood count, thyroid-stimulating hormone level, iron studies, serum electrolytes, blood urea nitrogen, and creatinine levels. Pregnancy testing, liver function tests, urinalysis, serum cortisol levels (after stimulation testing) and serologies for Epstein-Barr, hepatitis, or human immunodeficiency virus are frequently indicated. Other studies may be needed based on the clinical situation.

If baseline measurements (eg, maximal oxygen consumption, heart rate, and workload) are known, exercise testing may demonstrate a reduced physical performance capacity. These changes are not consistently present in overtraining syndrome and are not specific for the diagnosis. Documenting a reduced physical capacity could be helpful, however, if other objective indicators of performance decrements are not found in the athlete's history. Continuous electrocardiography and pre- and posttest spirometry can also be used to evaluate exercise-induced bronchospasm and other pulmonary conditions, cardiac ischemia, and arrhythmias.

Overtraining or Fatigue?

When evaluating a fatigued athlete during a vigorous training or competition cycle, the line between overreaching and overtraining syndrome is often difficult to discern. The response of the athlete to a 2-week trial of lighter training or rest can help sort out difficult cases. The symptoms of an athlete who has overtraining syndrome will not resolve during a short-term reduction of training, unlike many other causes of fatigue that may improve significantly.

When fatigue has been present more than a few weeks, overtraining syndrome becomes a more likely diagnosis. The initial symptom is often an increased level of fatigue during usually well-tolerated workouts. As the syndrome progresses, chronic fatigue at rest and other symptoms commonly develop (see table 1).

Diagnosis

Currently, overtraining syndrome remains a clinical diagnosis that has no laboratory, exercise, or psychological testing criteria. Testing is useful but should not be relied upon for diagnosis. A constellation of subjective physical and psychological symptoms are frequently present but are not included as part of the diagnostic criteria. Diagnosis of the syndrome requires exclusion of other causes of underperforming and persistence of performance impairment after more than 2 weeks of relative or complete rest.

Treatment

Since little data exist to guide the clinician in the treatment of overtraining syndrome, we will discuss practical approaches for developing treatment programs that have been successful in our experience and are consistent with other published methods.^2-4,12

Rest. Rest is the foundation of treatment for overtraining syndrome, because the condition represents an imbalance of stress and recovery. Koutedakis et al¹³ found that underperforming Olympic athletes in a variety of sports had improvements in maximal oxygen consumption, body weight, lactate threshold, and psychological factors after 3 to 5 weeks of rest. A well-performing control group of athletes had no change in parameters during the same period.

Prescribing prolonged rest to elite athletes who have a clinical syndrome, rather than a specific physical injury, can present challenging situations for the clinician. Resistance may arise from athletes, coaches, or administrators who are not familiar with the condition or have differing opinions on the cause of the athlete's fatigue and underperformance. Establishing an ongoing dialogue with interested parties and forging a trusting doctor-patient relationship with the athlete will improve the chances for a successful outcome.

Therapeutic exercise. No randomized controlled trials compare recovery patterns in athletes who are prescribed a significant decrease in training versus complete rest. Competitive athletes usually prefer a treatment plan based on "therapeutic exercise" rather than complete rest. The prescription should be tailored according to the degree of fatigue, duration of overtraining, and preference of the patient.

Relative rest consists of light aerobic exercise using a modality not related to the athlete's sport (eg, a swimmer may use an exercise bicycle, a runner may use an eliptical cross-trainer). This helps curb the temptation to compare their current volume and intensity of exercise to previous training experiences. Cross-training also increases the likelihood that they will adhere to a plan of exercise for therapy purposes, rather than return to training for performance enhancement.

Starting with 5 to 20 minutes of aerobic exercise at a heart rate less than 140/min ensures a light training load. Frequent discussions with the athlete and daily training diaries are useful for monitoring recovery. Simple dairies can include quantifying exercise volume and intensity with subjective scores for fatigue, sleep quality, stress levels, mood, and muscle soreness.

Mood monitoring. The POMS questionnaire is another option for monitoring recovery. As with any subjective feedback mechanism, be aware that some athletes may manipulate symptoms or responses. If scores or athletes' symptoms are steadily improving, exercise volume can be increased each week. Athletes should progress slowly, adding 5 to 10 minutes per week, until an hour of exercise is well tolerated. Six to 12 weeks is typically required before symptoms resolve and an hour of light exercise is tolerated.¹² Months or years of rest are required in a small number of patients.

Significant sports-related and non-sports-related psychosocial stressors should be adequately addressed. This may require coordination of care with a sports psychologist or other mental health professional familiar with the unique challenges of competitive athletics.

Athletes should be reassessed relatively soon after prescribed training reductions to assess compliance with rest and to monitor the psychological impact. Underlying mood state changes that accompany overtraining can initially worsen with recommended rest. No data are available to guide the decision for pharmacologic treatment of anxiety and depression symptoms. We recommend delaying treatment unless an underlying primary mood disorder is strongly suspected. Mood levels should slowly improve as physical recovery occurs.

Other modalities. Anecdotal adjuncts to rest include massage and hydrotherapy for persistent muscle soreness and stress reduction.^4,12 Nutritional practices should be optimized, with an emphasis on a balanced diet and proper hydration. Referral to a sports nutritionist can be beneficial.

Return to Play

Before advising a return to training or competition, mood state, fatigue, sleep quality, and muscle soreness should have normalized. A careful analysis of training factors that led to the syndrome should be identified. Training should be organized around principles of periodization (figure 2) to minimize the risk of the patient's having a relapse.^2-4,14,15 This should include at least 1 day a week of complete rest to allow for recovery. Monthly schedules should also have 1 lighter training week in the midst of heavier training weeks.

Training schedules should also be organized on a yearly calendar to ensure that adequate tapering time is available before competition. Olympic-level athletes may need to organize training on a 4-year schedule to peak at the desired times. Many excellent resources are available for further details on periodization of training.^14,15 Training cycles will differ by sport and by athletes' goals.

In team sports or group training situations, individual flexibility in workload is necessary to accommodate the different responses athletes have to the same training load. Clinicians may need to direct athletes toward consultation with expert coaches or exercise physiologists who are experienced in analyzing the periodization principles of the training program.

Monitoring. As the training levels begin to increase, athletes should be monitored for signs of maladaptation to training. Maintaining a training log and periodic POMS testing are relatively easy ways to evaluate training effects. A consistent downward trend in scores should prompt a reevaluation of the balances of stress and rest. Objective performance indicators and exercise testing may also be used to detect incomplete recovery or excessive training.

Clinician, coaches, and athletes will need to negotiate their respective roles in monitoring for excessive training. While instituting a formal monitoring program may provide additional information, no foolproof system exists that will guarantee against overtraining. Formal monitoring programs cannot serve as a substitute for good communication between the athlete and coaching staff in assessing the response to vigorous training.

Prevention Benefits

Because overtraining syndrome can prematurely end an athlete's season or career, prevention remains the ideal goal. The diagnosis is based on clinical assessment, since highly sensitive and specific tests are not yet available. The foundations of treatment are rest, minimizing psychosocial stressors, and improving nutrition. Identifying the training excesses that led to the athlete's declines will help prevent recurrence.

References

1. Kreider RB, Fry AC, O'Toole ML (eds): Overtraining in Sport. Champaign, IL, Human Kinetics, 1998
2. Mackinnon LT, Hooper SL: Overtraining and overreaching: causes, effects, and prevention, in Garrett WE, Kirkendall DT (eds): Exercise and Sport Science. Philadelphia, Lippincott Williams & Wilkins, 2000, pp 487-498
3. Fry RW, Morton AR, Keast D: Overtraining in athletes: an update. Sports Med 1991;12(1):32-65
4. Uusitalo AL: Overtraining: making a difficult diagnosis and implementing targeted treatment. Phys Sportsmed 2001;29(5):35-50
5. Urhausen A, Kindermann W: Diagnosis of overtraining: what tools do we have? Sports Med 2002;32(2):95-102
6. Armstrong LE, VanHeest JL: The unknown mechanism of the overtraining syndrome: clues from depression and psychoneuroimmunology. Sports Med 2002;32(3):185-209
7. Kreider RB, Fry AC, O'Toole ML: Overtraining and overreaching in sport: terms, definitions, and prevalence, in Kreider RB, Fry AC, O'Toole ML (eds): Overtraining in Sport. Champaign, IL, Human Kinetics, 1998, pp vii-ix
8. Morgan WP, Brown DR, Raglin JS, et al: Psychological monitoring of overtraining and staleness. Br J Sports Med 1987;21(3):107-114
9. Lehmann M, Foster C, Netzer N, et al: Physiological responses to short and long-term overtraining in endurance athletes, in Kreider RB, Fry AC, O'Toole ML (eds): Overtraining in Sport. Champaign, IL, Human Kinetics, 1998, pp 19-47
10. Hooper SL, Mackinnon LT, Howard A, et al: Markers for monitoring overtraining and recovery. Med Sci Sports Exerc 1995;27(1):106-112
11. McNair DM, Lorr M, Droppleman LF: POMS Manual: Profile of Mood States. San Diego, Educational and Industrial Testing Service, 1992
12. Budgett R: Fatigue and underperformance in athletes: the overtraining syndrome. Br J Sports Med 1998;32(2):107-110
13. Koutedakis Y, Budgett R, Faulmann L: Rest in underperforming elite competitors. Br J Sports Med 1990;24(4):248-252
14. Fry RW, Morton AR, Keast D: Periodisation and the prevention of overtraining. Can J Sport Sci 1992;17(3):241-248
15. Rowbottom DG: Periodization of training, in Garrett WE, Kirkendall DT (eds): Exercise and Sport Science. Philadelphia, Lippincott Williams & Wilkins, 2000, pp 499-512

Dr Hawley is a staff and team physician in the Sports Medicine Clinic of the University Health Services at the University of Texas in Austin. Dr Schoene is a professor of medicine in the division of pulmonary and critical care and director of clinical exercise testing at the University of Washington Medical Center in Seattle. Address correspondence to Christopher J. Hawley, MD, Box 7339, University Station, Austin, TX 78713; e-mail to chrishawley@usa.net.

Disclosure information: Drs Hawley and Schoene disclose no significant relationship with any manufacturer of any commercial product mentioned in this article. No drug is mentioned in this article for an unlabeled use.