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Can we detect non-functional overreaching in young elite soccer players and middle-long distance runners using field performance tests?
  1. S L Schmikli1,
  2. M S Brink2,3,
  3. W R de Vries1,
  4. F J G Backx1
  1. 1Rudolf Magnus Institute of Neuroscience, Department of Rehabilitation and Sports Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
  2. 2Center for Human Movement Sciences, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
  3. 3University Center for Sports, Exercise and Health, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
  1. Correspondence to Sandor L Schmikli, Rudolf Magnus Institute of Neuroscience, Deptartment of Rehabilitation and Sports Medicine, University Medical Center Utrecht, Utrecht 3508 GA, The Netherlands; s.l.schmikli{at}


Objective To study whether field performance tests can make a valid distinction between non-functionally overreaching (NFO) athletes and control athletes.

Design Monthly field performance tests were used to determine a performance decrement (PD) throughout a season. Athletes with a minimum of 1 month PD were compared with control athletes without a PD on mood characteristics and resting levels of stress hormones.

Setting Sporting field and sports medical laboratory.

Participants 129 young elite athletes, 77 soccer players and 52 middle-long distance runners were followed prospectively during the 2006–2007 season. Fifteen of them were invited to the laboratory. Eight athletes showed a performance decrease lasting longer than 1 month, and seven athletes without a performance decrease acted as their controls.

Main outcome measures Performance changes over time were measured using field tests. Profile of Mood States and resting levels of adrenocorticotrophic hormone (ACTH) and cortisol in blood were measured in the laboratory.

Results PD athletes showed several symptoms typical of the non-functional state of overreaching (OR). The PD group scored higher on depression and anger than controls. They also showed a specific pattern of correlations between negative mood subscales (tension, fatigue and depression), which was absent in controls. ACTH levels at rest were similar, but lower cortisol levels in PD athletes pointed at a blunted cortisol response. Cortisol levels were decoupled from ACTH levels only in PD athletes.

Conclusions Implementing performance-related criteria in field tests can help coaches and sports physicians to distinguish NFO athletes from athletes with balanced workload and recovery.

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  • Funding ZonMw, Den Haag, The Netherlands.

  • Competing interests None.

  • Ethics approval This study was conducted with the approval of the Central Committee on Research Ethics involving Human Subjects.

  • Provenance and peer review Not commissioned; externally peer reviewed.

    Detail has been removed from this case description/these case descriptions to ensure anonymity. The editors and reviewers have seen the detailed information available and are satisfied that the information backs up the case the authors are making.