Abstract
The Unexplained Underperformance Syndrome (UPS) is characterized by a continued decrement in athletic performance, unresolved by two weeks rest (Robson, 2003). This study qualitatively examined psychological factors of potential relevance to UPS, with specific consideration of the consequences of a mentally tough attitude in the interpretation of fatigue Seven elite athletes, clinically diagnosed with UPS or Chronic Fatigue, participated in one-to-one interviews to examine their experience of UPS The results of this study revealed a paradoxical relationship between mental toughness and UPS. Specifically, a mentally tough attitude, deemed desirable in competitive sport, obviated physiological markers of fatigue Furthermore, the results indicated that non-training related stressors appeared to have a pivotal influence on the onset of UPS.