The ‘unexplained underperformance syndrome’ (UUPS) is defined as a history of objective loss of performance, without a medical cause and despite two weeks of rest. This definition was arrived at by a group of experts in Oxford in 1999. They chose to call the syndrome UUPS as opposed to ‘over training’ to avoid restricting the cause to training per se.
UUPS is almost exclusively a condition of endurance athletes, commonly occurring after a period of heavy training and competition. There is often a his-tory of frequent minor infections.
Anecdotally it is thought that between 2% and 10% of elite endurance athletes suffer significant episodes of UUPS during their sporting careers. Often the condition occurs insidiously and remains undiagnosed for many weeks. The athlete typically will have sought advice from many quarters and have tried short periods of rest without success. Ideally the diagnosis of UUPS should be one that both athlete and coach agree upon.
Fatigue is the key presenting symptom. This fatigue persists despite rest and leads to underperformance. The athlete may lose motivation and often complains of sore muscles and poor sleep. Sometimes they may experience a loss of libido and appetite. They also often become depressed, and when this is clinically significant, it requires pharmacological treatment. It is often difficult for the athlete to determine whether the depression is the cause or the effect of the UUPS, but in my experience, if you do not treat the depression, you are likely to delay the resolution of the syndrome.
The onset of UUPS may coincide with upper respiratory tract infections, particularly viral. It is common, in taking the patient’s history, to find that they have trained intensively through a viral upper respiratory tract infection, leading to symptoms of fatigue.
Less common symptoms of UUPS include:
Sometimes the athlete has difficulty in raising his/her heart rate in exercise and a profound loss of motivation. It is important to stress that none of these symptoms are diagnostic or consistent across all UUPS subjects. Chronic fatigue syndrome is distinct from UUPS in that it is a more severe condition in which sufferers usually cannot even contemplate doing sport, and they recover less quickly.
Despite much ongoing excellent research work, there are as yet no unequivocal diagnostic serological (blood analysis), physiological or psychological markers for UUPS. Observations have included raised stress hormones and reticulocyte (immature red blood cell) counts, increased cortisol to testosterone ratios, raised neutrophil to lymphocyte ratios and lower branch chain amino acids. Some researchers have shown a relative loss of sympathetic neural tone in athletes with UUPS; this is the part of the nervous system which, among other things, increases heart rate. A loss of heart rate variability (HRV) occurs during morning postural testing and this reflects the loss of sympathetic neural tone. This may be useful in monitoring rehabilitation intensity during recovery from UUPS because the loss of HRV can be quantified and recovery thereby monitored.
Mood scores, whilst a helpful psychological tool in confirming the diagnosis, are neither sensitive nor specific. Serological markers may in future help provide a more accurate clinical diagnosis.
UUPS must not be confused with other medical causes of under performance. There is an extremely long list of differential diagnoses for fatigue in athletes, many of which can be excluded by taking a good history and (less importantly) examination of the athlete. Over the last 13 years I have seen 83 cases of athletes presenting with symptoms of UUPS, of which five (6%) had other medical causes. (Some clinicians report higher figures , but this may reflect the fact that many athletes I see have been through a medical screen prior to their consultation with me.) These included two cases of Epstein Barr infection (glandular fever), a Coxsacchie B myocarditis, an iron deficiency anaemia and a non-Hodgkin’s lymphoma. As a consequence of this I regularly perform a full blood count, ferritin, thyroid function test, ESR, urea and electrolytes and other blood tests as indicated by the history and examination. A pre- and post-exercise flow loop spirometry test, if the athlete can manage it, is helpful in the initial battery of tests.
The key to managing UUPS lies in a multi-disciplinary approach by a team of sports specialists, including physician, nutritionist, psychologist and physiologist. An experienced nutritionist should analyse a nutritional diary and the athlete’s carbohydrate ingestion before, during and after exercise. It is important to be able to rule out an eating disorder: the SCOFF questionnaire may be useful(1).
Many athletes with UUPS have coincident social, financial, domestic and career stresses, which a psychologist will need to explore. Physiologists with experience in heart rate variability monitoring can lead athlete and coach through the pulse-dependent rehabilitation that follows, and an early meeting between them is good practice.
The successful resolution of UUPS depends on clear communications between the multidisciplinary team and the athlete, their coach and family. It is really important to give the athlete a clear understanding of what is happening, and to make time to answer their questions throughout treatment and rehab. In my experience, recovery to full training often takes 10 to 15 weeks, during which time there should be regular team meetings, and meetings with the athlete and coach.
Psychological support throughout the whole process is very important to address the concerns of the athlete, family and coach. It is difficult for the athlete to accept that there is no ‘quick fix’ for UUPS and experienced consultation skills are required to address questions on the aetiology of UUPS where our know-ledge is, at best, incomplete. The multidisciplinary team must reflect regularly on the athlete’s clinical status, changing management swiftly when appropriate.
|Date||Fatigue||Muscle aches||Motivation||Upper respiratory tract symptoms||Other||Total|
There is no published evidence (to date) that one programme of management of UUPS is better than another. What follows is a pragmatic approach that has been adopted in the south-west region of the EIS, and which is regularly revised. Our strategy is based on symptom scoring and pulse-dependent rehabilitation (PDR). The athlete is asked early to score his/her symptoms in certain key areas (see Table 1). Significant symptoms are scored 1 – 10, less significant symptoms are given less weighting and are scored 1 – 5. Daily totals are collated (high is ‘bad’, low is ‘good’) and used to determine the progression of the PDR programme. We leave one column for ‘other’ symptoms that may be specific to the individual athlete’s history.
The PDR programme is agreed with the athlete and coach, and starts with a few weeks of complete rest, during which time the nutritionist and psychologist work with the athlete. The rate of progress thereafter is governed by improvements in the heart rate during exercise. The physician incrementally increases the volume and intensity of exercise based on heart rate response (see table 2).
|3||HR <120; 20 mins turbo training; 2 days off|
|4||HR <130; 20-25 mins TT; 2 days off|
|5||HR< 140; 30 mins TT; alternate days run 20 mins; 1 day off|
|6||HR < 150; 30 mins TT; run 20-30mins, swim 2k; 1 day off|
|7||HR 150-160 add short sprints (<10 secs)|
In institutes of sport and high performance centres the prevention of UUPS should be high on the agenda. A detailed review of the prevention of UUPS is beyond the scope of this article but the main issue is education of athletes and coaches. Overall attention to the ‘basics’ of sports exercise physiology; periodised training, carbohydrate and fluid replenishment and a holistic approach to athlete-centred training intensity are fundamental to maintaining the good health of the athlete.